Update jsoncpp to 1.9.4 (#10477)

Co-authored-by: Zughy <4279489-marco_a@users.noreply.gitlab.com>

4 files changed, 2473 insertions, 2283 deletions

diff --git a/lib/jsoncpp/json/UPDATING b/lib/jsoncpp/json/UPDATING
index f0226e8ee..0893244cf 100644
--- a/lib/jsoncpp/json/UPDATING
+++ b/lib/jsoncpp/json/UPDATING
@@ -1,6 +1,6 @@
 #!/bin/sh
 cd ..
-git clone https://github.com/open-source-parsers/jsoncpp -b 1.8.3 --depth 1
+git clone https://github.com/open-source-parsers/jsoncpp -b 1.9.4 --depth 1
 cd jsoncpp
 python amalgamate.py
 cp -R dist/json ../json
diff --git a/lib/jsoncpp/json/json-forwards.h b/lib/jsoncpp/json/json-forwards.h
index de2e4bd79..d3260c57c 100644
--- a/lib/jsoncpp/json/json-forwards.h
+++ b/lib/jsoncpp/json/json-forwards.h
@@ -80,6 +80,151 @@ license you like.
 #define JSON_IS_AMALGAMATION
 
 // //////////////////////////////////////////////////////////////////////
+// Beginning of content of file: include/json/version.h
+// //////////////////////////////////////////////////////////////////////
+
+#ifndef JSON_VERSION_H_INCLUDED
+#define JSON_VERSION_H_INCLUDED
+
+// Note: version must be updated in three places when doing a release. This
+// annoying process ensures that amalgamate, CMake, and meson all report the
+// correct version.
+// 1. /meson.build
+// 2. /include/json/version.h
+// 3. /CMakeLists.txt
+// IMPORTANT: also update the SOVERSION!!
+
+#define JSONCPP_VERSION_STRING "1.9.4"
+#define JSONCPP_VERSION_MAJOR 1
+#define JSONCPP_VERSION_MINOR 9
+#define JSONCPP_VERSION_PATCH 3
+#define JSONCPP_VERSION_QUALIFIER
+#define JSONCPP_VERSION_HEXA                                                   \
+  ((JSONCPP_VERSION_MAJOR << 24) | (JSONCPP_VERSION_MINOR << 16) |             \
+   (JSONCPP_VERSION_PATCH << 8))
+
+#ifdef JSONCPP_USING_SECURE_MEMORY
+#undef JSONCPP_USING_SECURE_MEMORY
+#endif
+#define JSONCPP_USING_SECURE_MEMORY 0
+// If non-zero, the library zeroes any memory that it has allocated before
+// it frees its memory.
+
+#endif // JSON_VERSION_H_INCLUDED
+
+// //////////////////////////////////////////////////////////////////////
+// End of content of file: include/json/version.h
+// //////////////////////////////////////////////////////////////////////
+
+
+
+
+
+
+// //////////////////////////////////////////////////////////////////////
+// Beginning of content of file: include/json/allocator.h
+// //////////////////////////////////////////////////////////////////////
+
+// Copyright 2007-2010 Baptiste Lepilleur and The JsonCpp Authors
+// Distributed under MIT license, or public domain if desired and
+// recognized in your jurisdiction.
+// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
+
+#ifndef JSON_ALLOCATOR_H_INCLUDED
+#define JSON_ALLOCATOR_H_INCLUDED
+
+#include <cstring>
+#include <memory>
+
+#pragma pack(push, 8)
+
+namespace Json {
+template <typename T> class SecureAllocator {
+public:
+  // Type definitions
+  using value_type = T;
+  using pointer = T*;
+  using const_pointer = const T*;
+  using reference = T&;
+  using const_reference = const T&;
+  using size_type = std::size_t;
+  using difference_type = std::ptrdiff_t;
+
+  /**
+   * Allocate memory for N items using the standard allocator.
+   */
+  pointer allocate(size_type n) {
+    // allocate using "global operator new"
+    return static_cast<pointer>(::operator new(n * sizeof(T)));
+  }
+
+  /**
+   * Release memory which was allocated for N items at pointer P.
+   *
+   * The memory block is filled with zeroes before being released.
+   * The pointer argument is tagged as "volatile" to prevent the
+   * compiler optimizing out this critical step.
+   */
+  void deallocate(volatile pointer p, size_type n) {
+    std::memset(p, 0, n * sizeof(T));
+    // free using "global operator delete"
+    ::operator delete(p);
+  }
+
+  /**
+   * Construct an item in-place at pointer P.
+   */
+  template <typename... Args> void construct(pointer p, Args&&... args) {
+    // construct using "placement new" and "perfect forwarding"
+    ::new (static_cast<void*>(p)) T(std::forward<Args>(args)...);
+  }
+
+  size_type max_size() const { return size_t(-1) / sizeof(T); }
+
+  pointer address(reference x) const { return std::addressof(x); }
+
+  const_pointer address(const_reference x) const { return std::addressof(x); }
+
+  /**
+   * Destroy an item in-place at pointer P.
+   */
+  void destroy(pointer p) {
+    // destroy using "explicit destructor"
+    p->~T();
+  }
+
+  // Boilerplate
+  SecureAllocator() {}
+  template <typename U> SecureAllocator(const SecureAllocator<U>&) {}
+  template <typename U> struct rebind { using other = SecureAllocator<U>; };
+};
+
+template <typename T, typename U>
+bool operator==(const SecureAllocator<T>&, const SecureAllocator<U>&) {
+  return true;
+}
+
+template <typename T, typename U>
+bool operator!=(const SecureAllocator<T>&, const SecureAllocator<U>&) {
+  return false;
+}
+
+} // namespace Json
+
+#pragma pack(pop)
+
+#endif // JSON_ALLOCATOR_H_INCLUDED
+
+// //////////////////////////////////////////////////////////////////////
+// End of content of file: include/json/allocator.h
+// //////////////////////////////////////////////////////////////////////
+
+
+
+
+
+
+// //////////////////////////////////////////////////////////////////////
 // Beginning of content of file: include/json/config.h
 // //////////////////////////////////////////////////////////////////////
 
@@ -90,19 +235,14 @@ license you like.
 
 #ifndef JSON_CONFIG_H_INCLUDED
 #define JSON_CONFIG_H_INCLUDED
-#include <stddef.h>
-#include <string> //typedef String
-#include <stdint.h> //typedef int64_t, uint64_t
-
-/// If defined, indicates that json library is embedded in CppTL library.
-//# define JSON_IN_CPPTL 1
-
-/// If defined, indicates that json may leverage CppTL library
-//#  define JSON_USE_CPPTL 1
-/// If defined, indicates that cpptl vector based map should be used instead of
-/// std::map
-/// as Value container.
-//#  define JSON_USE_CPPTL_SMALLMAP 1
+#include <cstddef>
+#include <cstdint>
+#include <istream>
+#include <memory>
+#include <ostream>
+#include <sstream>
+#include <string>
+#include <type_traits>
 
 // If non-zero, the library uses exceptions to report bad input instead of C
 // assertion macros. The default is to use exceptions.
@@ -110,164 +250,132 @@ license you like.
 #define JSON_USE_EXCEPTION 1
 #endif
 
+// Temporary, tracked for removal with issue #982.
+#ifndef JSON_USE_NULLREF
+#define JSON_USE_NULLREF 1
+#endif
+
 /// If defined, indicates that the source file is amalgamated
 /// to prevent private header inclusion.
 /// Remarks: it is automatically defined in the generated amalgamated header.
 // #define JSON_IS_AMALGAMATION
 
-#ifdef JSON_IN_CPPTL
-#include <cpptl/config.h>
-#ifndef JSON_USE_CPPTL
-#define JSON_USE_CPPTL 1
-#endif
-#endif
-
-#ifdef JSON_IN_CPPTL
-#define JSON_API CPPTL_API
-#elif defined(JSON_DLL_BUILD)
+// Export macros for DLL visibility
+#if defined(JSON_DLL_BUILD)
 #if defined(_MSC_VER) || defined(__MINGW32__)
 #define JSON_API __declspec(dllexport)
 #define JSONCPP_DISABLE_DLL_INTERFACE_WARNING
+#elif defined(__GNUC__) || defined(__clang__)
+#define JSON_API __attribute__((visibility("default")))
 #endif // if defined(_MSC_VER)
+
 #elif defined(JSON_DLL)
 #if defined(_MSC_VER) || defined(__MINGW32__)
 #define JSON_API __declspec(dllimport)
 #define JSONCPP_DISABLE_DLL_INTERFACE_WARNING
 #endif // if defined(_MSC_VER)
-#endif // ifdef JSON_IN_CPPTL
+#endif // ifdef JSON_DLL_BUILD
+
 #if !defined(JSON_API)
 #define JSON_API
 #endif
 
-// If JSON_NO_INT64 is defined, then Json only support C++ "int" type for
-// integer
-// Storages, and 64 bits integer support is disabled.
-// #define JSON_NO_INT64 1
+#if defined(_MSC_VER) && _MSC_VER < 1800
+#error                                                                         \
+    "ERROR:  Visual Studio 12 (2013) with _MSC_VER=1800 is the oldest supported compiler with sufficient C++11 capabilities"
+#endif
 
-#if defined(_MSC_VER) // MSVC
-#  if _MSC_VER <= 1200 // MSVC 6
-    // Microsoft Visual Studio 6 only support conversion from __int64 to double
-    // (no conversion from unsigned __int64).
-#    define JSON_USE_INT64_DOUBLE_CONVERSION 1
-    // Disable warning 4786 for VS6 caused by STL (identifier was truncated to '255'
-    // characters in the debug information)
-    // All projects I've ever seen with VS6 were using this globally (not bothering
-    // with pragma push/pop).
-#    pragma warning(disable : 4786)
-#  endif // MSVC 6
-
-#  if _MSC_VER >= 1500 // MSVC 2008
-    /// Indicates that the following function is deprecated.
-#    define JSONCPP_DEPRECATED(message) __declspec(deprecated(message))
-#  endif
-
-#endif // defined(_MSC_VER)
-
-// In c++11 the override keyword allows you to explicitly define that a function
-// is intended to override the base-class version.  This makes the code more
-// managable and fixes a set of common hard-to-find bugs.
-#if __cplusplus >= 201103L
-# define JSONCPP_OVERRIDE override
-# define JSONCPP_NOEXCEPT noexcept
-#elif defined(_MSC_VER) && _MSC_VER > 1600 && _MSC_VER < 1900
-# define JSONCPP_OVERRIDE override
-# define JSONCPP_NOEXCEPT throw()
-#elif defined(_MSC_VER) && _MSC_VER >= 1900
-# define JSONCPP_OVERRIDE override
-# define JSONCPP_NOEXCEPT noexcept
+#if defined(_MSC_VER) && _MSC_VER < 1900
+// As recommended at
+// https://stackoverflow.com/questions/2915672/snprintf-and-visual-studio-2010
+extern JSON_API int msvc_pre1900_c99_snprintf(char* outBuf, size_t size,
+                                              const char* format, ...);
+#define jsoncpp_snprintf msvc_pre1900_c99_snprintf
 #else
-# define JSONCPP_OVERRIDE
-# define JSONCPP_NOEXCEPT throw()
+#define jsoncpp_snprintf std::snprintf
 #endif
 
-#ifndef JSON_HAS_RVALUE_REFERENCES
+// If JSON_NO_INT64 is defined, then Json only support C++ "int" type for
+// integer
+// Storages, and 64 bits integer support is disabled.
+// #define JSON_NO_INT64 1
 
-#if defined(_MSC_VER) && _MSC_VER >= 1600 // MSVC >= 2010
-#define JSON_HAS_RVALUE_REFERENCES 1
-#endif // MSVC >= 2010
+// JSONCPP_OVERRIDE is maintained for backwards compatibility of external tools.
+// C++11 should be used directly in JSONCPP.
+#define JSONCPP_OVERRIDE override
 
 #ifdef __clang__
-#if __has_feature(cxx_rvalue_references)
-#define JSON_HAS_RVALUE_REFERENCES 1
-#endif  // has_feature
-
-#elif defined __GNUC__ // not clang (gcc comes later since clang emulates gcc)
-#if defined(__GXX_EXPERIMENTAL_CXX0X__) || (__cplusplus >= 201103L)
-#define JSON_HAS_RVALUE_REFERENCES 1
-#endif  // GXX_EXPERIMENTAL
-
-#endif // __clang__ || __GNUC__
-
-#endif // not defined JSON_HAS_RVALUE_REFERENCES
-
-#ifndef JSON_HAS_RVALUE_REFERENCES
-#define JSON_HAS_RVALUE_REFERENCES 0
+#if __has_extension(attribute_deprecated_with_message)
+#define JSONCPP_DEPRECATED(message) __attribute__((deprecated(message)))
 #endif
-
-#ifdef __clang__
-#  if __has_extension(attribute_deprecated_with_message)
-#    define JSONCPP_DEPRECATED(message)  __attribute__ ((deprecated(message)))
-#  endif
-#elif defined __GNUC__ // not clang (gcc comes later since clang emulates gcc)
-#  if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5))
-#    define JSONCPP_DEPRECATED(message)  __attribute__ ((deprecated(message)))
-#  elif (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
-#    define JSONCPP_DEPRECATED(message)  __attribute__((__deprecated__))
-#  endif  // GNUC version
-#endif // __clang__ || __GNUC__
+#elif defined(__GNUC__) // not clang (gcc comes later since clang emulates gcc)
+#if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5))
+#define JSONCPP_DEPRECATED(message) __attribute__((deprecated(message)))
+#elif (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
+#define JSONCPP_DEPRECATED(message) __attribute__((__deprecated__))
+#endif                  // GNUC version
+#elif defined(_MSC_VER) // MSVC (after clang because clang on Windows emulates
+                        // MSVC)
+#define JSONCPP_DEPRECATED(message) __declspec(deprecated(message))
+#endif // __clang__ || __GNUC__ || _MSC_VER
 
 #if !defined(JSONCPP_DEPRECATED)
 #define JSONCPP_DEPRECATED(message)
 #endif // if !defined(JSONCPP_DEPRECATED)
 
-#if __GNUC__ >= 6
-#  define JSON_USE_INT64_DOUBLE_CONVERSION 1
+#if defined(__clang__) || (defined(__GNUC__) && (__GNUC__ >= 6))
+#define JSON_USE_INT64_DOUBLE_CONVERSION 1
 #endif
 
 #if !defined(JSON_IS_AMALGAMATION)
 
-# include "version.h"
-
-# if JSONCPP_USING_SECURE_MEMORY
-#  include "allocator.h" //typedef Allocator
-# endif
+#include "allocator.h"
+#include "version.h"
 
 #endif // if !defined(JSON_IS_AMALGAMATION)
 
 namespace Json {
-typedef int Int;
-typedef unsigned int UInt;
+using Int = int;
+using UInt = unsigned int;
 #if defined(JSON_NO_INT64)
-typedef int LargestInt;
-typedef unsigned int LargestUInt;
+using LargestInt = int;
+using LargestUInt = unsigned int;
 #undef JSON_HAS_INT64
 #else                 // if defined(JSON_NO_INT64)
 // For Microsoft Visual use specific types as long long is not supported
 #if defined(_MSC_VER) // Microsoft Visual Studio
-typedef __int64 Int64;
-typedef unsigned __int64 UInt64;
+using Int64 = __int64;
+using UInt64 = unsigned __int64;
 #else                 // if defined(_MSC_VER) // Other platforms, use long long
-typedef int64_t Int64;
-typedef uint64_t UInt64;
-#endif // if defined(_MSC_VER)
-typedef Int64 LargestInt;
-typedef UInt64 LargestUInt;
+using Int64 = int64_t;
+using UInt64 = uint64_t;
+#endif                // if defined(_MSC_VER)
+using LargestInt = Int64;
+using LargestUInt = UInt64;
 #define JSON_HAS_INT64
 #endif // if defined(JSON_NO_INT64)
-#if JSONCPP_USING_SECURE_MEMORY
-#define JSONCPP_STRING        std::basic_string<char, std::char_traits<char>, Json::SecureAllocator<char> >
-#define JSONCPP_OSTRINGSTREAM std::basic_ostringstream<char, std::char_traits<char>, Json::SecureAllocator<char> >
-#define JSONCPP_OSTREAM       std::basic_ostream<char, std::char_traits<char>>
-#define JSONCPP_ISTRINGSTREAM std::basic_istringstream<char, std::char_traits<char>, Json::SecureAllocator<char> >
-#define JSONCPP_ISTREAM       std::istream
-#else
-#define JSONCPP_STRING        std::string
-#define JSONCPP_OSTRINGSTREAM std::ostringstream
-#define JSONCPP_OSTREAM       std::ostream
-#define JSONCPP_ISTRINGSTREAM std::istringstream
-#define JSONCPP_ISTREAM       std::istream
-#endif // if JSONCPP_USING_SECURE_MEMORY
-} // end namespace Json
+
+template <typename T>
+using Allocator =
+    typename std::conditional<JSONCPP_USING_SECURE_MEMORY, SecureAllocator<T>,
+                              std::allocator<T>>::type;
+using String = std::basic_string<char, std::char_traits<char>, Allocator<char>>;
+using IStringStream =
+    std::basic_istringstream<String::value_type, String::traits_type,
+                             String::allocator_type>;
+using OStringStream =
+    std::basic_ostringstream<String::value_type, String::traits_type,
+                             String::allocator_type>;
+using IStream = std::istream;
+using OStream = std::ostream;
+} // namespace Json
+
+// Legacy names (formerly macros).
+using JSONCPP_STRING = Json::String;
+using JSONCPP_ISTRINGSTREAM = Json::IStringStream;
+using JSONCPP_OSTRINGSTREAM = Json::OStringStream;
+using JSONCPP_ISTREAM = Json::IStream;
+using JSONCPP_OSTREAM = Json::OStream;
 
 #endif // JSON_CONFIG_H_INCLUDED
 
@@ -299,17 +407,23 @@ typedef UInt64 LargestUInt;
 namespace Json {
 
 // writer.h
+class StreamWriter;
+class StreamWriterBuilder;
+class Writer;
 class FastWriter;
 class StyledWriter;
+class StyledStreamWriter;
 
 // reader.h
 class Reader;
+class CharReader;
+class CharReaderBuilder;
 
-// features.h
+// json_features.h
 class Features;
 
 // value.h
-typedef unsigned int ArrayIndex;
+using ArrayIndex = unsigned int;
 class StaticString;
 class Path;
 class PathArgument;
diff --git a/lib/jsoncpp/json/json.h b/lib/jsoncpp/json/json.h
index 625ba02e9..3f4813a95 100644
--- a/lib/jsoncpp/json/json.h
+++ b/lib/jsoncpp/json/json.h
@@ -82,17 +82,25 @@ license you like.
 // Beginning of content of file: include/json/version.h
 // //////////////////////////////////////////////////////////////////////
 
-// DO NOT EDIT. This file (and "version") is generated by CMake.
-// Run CMake configure step to update it.
 #ifndef JSON_VERSION_H_INCLUDED
-# define JSON_VERSION_H_INCLUDED
-
-# define JSONCPP_VERSION_STRING "1.8.4"
-# define JSONCPP_VERSION_MAJOR 1
-# define JSONCPP_VERSION_MINOR 8
-# define JSONCPP_VERSION_PATCH 4
-# define JSONCPP_VERSION_QUALIFIER
-# define JSONCPP_VERSION_HEXA ((JSONCPP_VERSION_MAJOR << 24) | (JSONCPP_VERSION_MINOR << 16) | (JSONCPP_VERSION_PATCH << 8))
+#define JSON_VERSION_H_INCLUDED
+
+// Note: version must be updated in three places when doing a release. This
+// annoying process ensures that amalgamate, CMake, and meson all report the
+// correct version.
+// 1. /meson.build
+// 2. /include/json/version.h
+// 3. /CMakeLists.txt
+// IMPORTANT: also update the SOVERSION!!
+
+#define JSONCPP_VERSION_STRING "1.9.4"
+#define JSONCPP_VERSION_MAJOR 1
+#define JSONCPP_VERSION_MINOR 9
+#define JSONCPP_VERSION_PATCH 3
+#define JSONCPP_VERSION_QUALIFIER
+#define JSONCPP_VERSION_HEXA                                                   \
+  ((JSONCPP_VERSION_MAJOR << 24) | (JSONCPP_VERSION_MINOR << 16) |             \
+   (JSONCPP_VERSION_PATCH << 8))
 
 #ifdef JSONCPP_USING_SECURE_MEMORY
 #undef JSONCPP_USING_SECURE_MEMORY
@@ -113,6 +121,109 @@ license you like.
 
 
 // //////////////////////////////////////////////////////////////////////
+// Beginning of content of file: include/json/allocator.h
+// //////////////////////////////////////////////////////////////////////
+
+// Copyright 2007-2010 Baptiste Lepilleur and The JsonCpp Authors
+// Distributed under MIT license, or public domain if desired and
+// recognized in your jurisdiction.
+// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
+
+#ifndef JSON_ALLOCATOR_H_INCLUDED
+#define JSON_ALLOCATOR_H_INCLUDED
+
+#include <cstring>
+#include <memory>
+
+#pragma pack(push, 8)
+
+namespace Json {
+template <typename T> class SecureAllocator {
+public:
+  // Type definitions
+  using value_type = T;
+  using pointer = T*;
+  using const_pointer = const T*;
+  using reference = T&;
+  using const_reference = const T&;
+  using size_type = std::size_t;
+  using difference_type = std::ptrdiff_t;
+
+  /**
+   * Allocate memory for N items using the standard allocator.
+   */
+  pointer allocate(size_type n) {
+    // allocate using "global operator new"
+    return static_cast<pointer>(::operator new(n * sizeof(T)));
+  }
+
+  /**
+   * Release memory which was allocated for N items at pointer P.
+   *
+   * The memory block is filled with zeroes before being released.
+   * The pointer argument is tagged as "volatile" to prevent the
+   * compiler optimizing out this critical step.
+   */
+  void deallocate(volatile pointer p, size_type n) {
+    std::memset(p, 0, n * sizeof(T));
+    // free using "global operator delete"
+    ::operator delete(p);
+  }
+
+  /**
+   * Construct an item in-place at pointer P.
+   */
+  template <typename... Args> void construct(pointer p, Args&&... args) {
+    // construct using "placement new" and "perfect forwarding"
+    ::new (static_cast<void*>(p)) T(std::forward<Args>(args)...);
+  }
+
+  size_type max_size() const { return size_t(-1) / sizeof(T); }
+
+  pointer address(reference x) const { return std::addressof(x); }
+
+  const_pointer address(const_reference x) const { return std::addressof(x); }
+
+  /**
+   * Destroy an item in-place at pointer P.
+   */
+  void destroy(pointer p) {
+    // destroy using "explicit destructor"
+    p->~T();
+  }
+
+  // Boilerplate
+  SecureAllocator() {}
+  template <typename U> SecureAllocator(const SecureAllocator<U>&) {}
+  template <typename U> struct rebind { using other = SecureAllocator<U>; };
+};
+
+template <typename T, typename U>
+bool operator==(const SecureAllocator<T>&, const SecureAllocator<U>&) {
+  return true;
+}
+
+template <typename T, typename U>
+bool operator!=(const SecureAllocator<T>&, const SecureAllocator<U>&) {
+  return false;
+}
+
+} // namespace Json
+
+#pragma pack(pop)
+
+#endif // JSON_ALLOCATOR_H_INCLUDED
+
+// //////////////////////////////////////////////////////////////////////
+// End of content of file: include/json/allocator.h
+// //////////////////////////////////////////////////////////////////////
+
+
+
+
+
+
+// //////////////////////////////////////////////////////////////////////
 // Beginning of content of file: include/json/config.h
 // //////////////////////////////////////////////////////////////////////
 
@@ -123,19 +234,14 @@ license you like.
 
 #ifndef JSON_CONFIG_H_INCLUDED
 #define JSON_CONFIG_H_INCLUDED
-#include <stddef.h>
-#include <string> //typedef String
-#include <stdint.h> //typedef int64_t, uint64_t
-
-/// If defined, indicates that json library is embedded in CppTL library.
-//# define JSON_IN_CPPTL 1
-
-/// If defined, indicates that json may leverage CppTL library
-//#  define JSON_USE_CPPTL 1
-/// If defined, indicates that cpptl vector based map should be used instead of
-/// std::map
-/// as Value container.
-//#  define JSON_USE_CPPTL_SMALLMAP 1
+#include <cstddef>
+#include <cstdint>
+#include <istream>
+#include <memory>
+#include <ostream>
+#include <sstream>
+#include <string>
+#include <type_traits>
 
 // If non-zero, the library uses exceptions to report bad input instead of C
 // assertion macros. The default is to use exceptions.
@@ -143,164 +249,132 @@ license you like.
 #define JSON_USE_EXCEPTION 1
 #endif
 
+// Temporary, tracked for removal with issue #982.
+#ifndef JSON_USE_NULLREF
+#define JSON_USE_NULLREF 1
+#endif
+
 /// If defined, indicates that the source file is amalgamated
 /// to prevent private header inclusion.
 /// Remarks: it is automatically defined in the generated amalgamated header.
 // #define JSON_IS_AMALGAMATION
 
-#ifdef JSON_IN_CPPTL
-#include <cpptl/config.h>
-#ifndef JSON_USE_CPPTL
-#define JSON_USE_CPPTL 1
-#endif
-#endif
-
-#ifdef JSON_IN_CPPTL
-#define JSON_API CPPTL_API
-#elif defined(JSON_DLL_BUILD)
+// Export macros for DLL visibility
+#if defined(JSON_DLL_BUILD)
 #if defined(_MSC_VER) || defined(__MINGW32__)
 #define JSON_API __declspec(dllexport)
 #define JSONCPP_DISABLE_DLL_INTERFACE_WARNING
+#elif defined(__GNUC__) || defined(__clang__)
+#define JSON_API __attribute__((visibility("default")))
 #endif // if defined(_MSC_VER)
+
 #elif defined(JSON_DLL)
 #if defined(_MSC_VER) || defined(__MINGW32__)
 #define JSON_API __declspec(dllimport)
 #define JSONCPP_DISABLE_DLL_INTERFACE_WARNING
 #endif // if defined(_MSC_VER)
-#endif // ifdef JSON_IN_CPPTL
+#endif // ifdef JSON_DLL_BUILD
+
 #if !defined(JSON_API)
 #define JSON_API
 #endif
 
-// If JSON_NO_INT64 is defined, then Json only support C++ "int" type for
-// integer
-// Storages, and 64 bits integer support is disabled.
-// #define JSON_NO_INT64 1
+#if defined(_MSC_VER) && _MSC_VER < 1800
+#error                                                                         \
+    "ERROR:  Visual Studio 12 (2013) with _MSC_VER=1800 is the oldest supported compiler with sufficient C++11 capabilities"
+#endif
 
-#if defined(_MSC_VER) // MSVC
-#  if _MSC_VER <= 1200 // MSVC 6
-    // Microsoft Visual Studio 6 only support conversion from __int64 to double
-    // (no conversion from unsigned __int64).
-#    define JSON_USE_INT64_DOUBLE_CONVERSION 1
-    // Disable warning 4786 for VS6 caused by STL (identifier was truncated to '255'
-    // characters in the debug information)
-    // All projects I've ever seen with VS6 were using this globally (not bothering
-    // with pragma push/pop).
-#    pragma warning(disable : 4786)
-#  endif // MSVC 6
-
-#  if _MSC_VER >= 1500 // MSVC 2008
-    /// Indicates that the following function is deprecated.
-#    define JSONCPP_DEPRECATED(message) __declspec(deprecated(message))
-#  endif
-
-#endif // defined(_MSC_VER)
-
-// In c++11 the override keyword allows you to explicitly define that a function
-// is intended to override the base-class version.  This makes the code more
-// managable and fixes a set of common hard-to-find bugs.
-#if __cplusplus >= 201103L
-# define JSONCPP_OVERRIDE override
-# define JSONCPP_NOEXCEPT noexcept
-#elif defined(_MSC_VER) && _MSC_VER > 1600 && _MSC_VER < 1900
-# define JSONCPP_OVERRIDE override
-# define JSONCPP_NOEXCEPT throw()
-#elif defined(_MSC_VER) && _MSC_VER >= 1900
-# define JSONCPP_OVERRIDE override
-# define JSONCPP_NOEXCEPT noexcept
+#if defined(_MSC_VER) && _MSC_VER < 1900
+// As recommended at
+// https://stackoverflow.com/questions/2915672/snprintf-and-visual-studio-2010
+extern JSON_API int msvc_pre1900_c99_snprintf(char* outBuf, size_t size,
+                                              const char* format, ...);
+#define jsoncpp_snprintf msvc_pre1900_c99_snprintf
 #else
-# define JSONCPP_OVERRIDE
-# define JSONCPP_NOEXCEPT throw()
+#define jsoncpp_snprintf std::snprintf
 #endif
 
-#ifndef JSON_HAS_RVALUE_REFERENCES
+// If JSON_NO_INT64 is defined, then Json only support C++ "int" type for
+// integer
+// Storages, and 64 bits integer support is disabled.
+// #define JSON_NO_INT64 1
 
-#if defined(_MSC_VER) && _MSC_VER >= 1600 // MSVC >= 2010
-#define JSON_HAS_RVALUE_REFERENCES 1
-#endif // MSVC >= 2010
+// JSONCPP_OVERRIDE is maintained for backwards compatibility of external tools.
+// C++11 should be used directly in JSONCPP.
+#define JSONCPP_OVERRIDE override
 
 #ifdef __clang__
-#if __has_feature(cxx_rvalue_references)
-#define JSON_HAS_RVALUE_REFERENCES 1
-#endif  // has_feature
-
-#elif defined __GNUC__ // not clang (gcc comes later since clang emulates gcc)
-#if defined(__GXX_EXPERIMENTAL_CXX0X__) || (__cplusplus >= 201103L)
-#define JSON_HAS_RVALUE_REFERENCES 1
-#endif  // GXX_EXPERIMENTAL
-
-#endif // __clang__ || __GNUC__
-
-#endif // not defined JSON_HAS_RVALUE_REFERENCES
-
-#ifndef JSON_HAS_RVALUE_REFERENCES
-#define JSON_HAS_RVALUE_REFERENCES 0
+#if __has_extension(attribute_deprecated_with_message)
+#define JSONCPP_DEPRECATED(message) __attribute__((deprecated(message)))
 #endif
-
-#ifdef __clang__
-#  if __has_extension(attribute_deprecated_with_message)
-#    define JSONCPP_DEPRECATED(message)  __attribute__ ((deprecated(message)))
-#  endif
-#elif defined __GNUC__ // not clang (gcc comes later since clang emulates gcc)
-#  if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5))
-#    define JSONCPP_DEPRECATED(message)  __attribute__ ((deprecated(message)))
-#  elif (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
-#    define JSONCPP_DEPRECATED(message)  __attribute__((__deprecated__))
-#  endif  // GNUC version
-#endif // __clang__ || __GNUC__
+#elif defined(__GNUC__) // not clang (gcc comes later since clang emulates gcc)
+#if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5))
+#define JSONCPP_DEPRECATED(message) __attribute__((deprecated(message)))
+#elif (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
+#define JSONCPP_DEPRECATED(message) __attribute__((__deprecated__))
+#endif                  // GNUC version
+#elif defined(_MSC_VER) // MSVC (after clang because clang on Windows emulates
+                        // MSVC)
+#define JSONCPP_DEPRECATED(message) __declspec(deprecated(message))
+#endif // __clang__ || __GNUC__ || _MSC_VER
 
 #if !defined(JSONCPP_DEPRECATED)
 #define JSONCPP_DEPRECATED(message)
 #endif // if !defined(JSONCPP_DEPRECATED)
 
-#if __GNUC__ >= 6
-#  define JSON_USE_INT64_DOUBLE_CONVERSION 1
+#if defined(__clang__) || (defined(__GNUC__) && (__GNUC__ >= 6))
+#define JSON_USE_INT64_DOUBLE_CONVERSION 1
 #endif
 
 #if !defined(JSON_IS_AMALGAMATION)
 
-# include "version.h"
-
-# if JSONCPP_USING_SECURE_MEMORY
-#  include "allocator.h" //typedef Allocator
-# endif
+#include "allocator.h"
+#include "version.h"
 
 #endif // if !defined(JSON_IS_AMALGAMATION)
 
 namespace Json {
-typedef int Int;
-typedef unsigned int UInt;
+using Int = int;
+using UInt = unsigned int;
 #if defined(JSON_NO_INT64)
-typedef int LargestInt;
-typedef unsigned int LargestUInt;
+using LargestInt = int;
+using LargestUInt = unsigned int;
 #undef JSON_HAS_INT64
 #else                 // if defined(JSON_NO_INT64)
 // For Microsoft Visual use specific types as long long is not supported
 #if defined(_MSC_VER) // Microsoft Visual Studio
-typedef __int64 Int64;
-typedef unsigned __int64 UInt64;
+using Int64 = __int64;
+using UInt64 = unsigned __int64;
 #else                 // if defined(_MSC_VER) // Other platforms, use long long
-typedef int64_t Int64;
-typedef uint64_t UInt64;
-#endif // if defined(_MSC_VER)
-typedef Int64 LargestInt;
-typedef UInt64 LargestUInt;
+using Int64 = int64_t;
+using UInt64 = uint64_t;
+#endif                // if defined(_MSC_VER)
+using LargestInt = Int64;
+using LargestUInt = UInt64;
 #define JSON_HAS_INT64
 #endif // if defined(JSON_NO_INT64)
-#if JSONCPP_USING_SECURE_MEMORY
-#define JSONCPP_STRING        std::basic_string<char, std::char_traits<char>, Json::SecureAllocator<char> >
-#define JSONCPP_OSTRINGSTREAM std::basic_ostringstream<char, std::char_traits<char>, Json::SecureAllocator<char> >
-#define JSONCPP_OSTREAM       std::basic_ostream<char, std::char_traits<char>>
-#define JSONCPP_ISTRINGSTREAM std::basic_istringstream<char, std::char_traits<char>, Json::SecureAllocator<char> >
-#define JSONCPP_ISTREAM       std::istream
-#else
-#define JSONCPP_STRING        std::string
-#define JSONCPP_OSTRINGSTREAM std::ostringstream
-#define JSONCPP_OSTREAM       std::ostream
-#define JSONCPP_ISTRINGSTREAM std::istringstream
-#define JSONCPP_ISTREAM       std::istream
-#endif // if JSONCPP_USING_SECURE_MEMORY
-} // end namespace Json
+
+template <typename T>
+using Allocator =
+    typename std::conditional<JSONCPP_USING_SECURE_MEMORY, SecureAllocator<T>,
+                              std::allocator<T>>::type;
+using String = std::basic_string<char, std::char_traits<char>, Allocator<char>>;
+using IStringStream =
+    std::basic_istringstream<String::value_type, String::traits_type,
+                             String::allocator_type>;
+using OStringStream =
+    std::basic_ostringstream<String::value_type, String::traits_type,
+                             String::allocator_type>;
+using IStream = std::istream;
+using OStream = std::ostream;
+} // namespace Json
+
+// Legacy names (formerly macros).
+using JSONCPP_STRING = Json::String;
+using JSONCPP_ISTRINGSTREAM = Json::IStringStream;
+using JSONCPP_OSTRINGSTREAM = Json::OStringStream;
+using JSONCPP_ISTREAM = Json::IStream;
+using JSONCPP_OSTREAM = Json::OStream;
 
 #endif // JSON_CONFIG_H_INCLUDED
 
@@ -332,17 +406,23 @@ typedef UInt64 LargestUInt;
 namespace Json {
 
 // writer.h
+class StreamWriter;
+class StreamWriterBuilder;
+class Writer;
 class FastWriter;
 class StyledWriter;
+class StyledStreamWriter;
 
 // reader.h
 class Reader;
+class CharReader;
+class CharReaderBuilder;
 
-// features.h
+// json_features.h
 class Features;
 
 // value.h
-typedef unsigned int ArrayIndex;
+using ArrayIndex = unsigned int;
 class StaticString;
 class Path;
 class PathArgument;
@@ -365,7 +445,7 @@ class ValueConstIterator;
 
 
 // //////////////////////////////////////////////////////////////////////
-// Beginning of content of file: include/json/features.h
+// Beginning of content of file: include/json/json_features.h
 // //////////////////////////////////////////////////////////////////////
 
 // Copyright 2007-2010 Baptiste Lepilleur and The JsonCpp Authors
@@ -373,8 +453,8 @@ class ValueConstIterator;
 // recognized in your jurisdiction.
 // See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
 
-#ifndef CPPTL_JSON_FEATURES_H_INCLUDED
-#define CPPTL_JSON_FEATURES_H_INCLUDED
+#ifndef JSON_FEATURES_H_INCLUDED
+#define JSON_FEATURES_H_INCLUDED
 
 #if !defined(JSON_IS_AMALGAMATION)
 #include "forwards.h"
@@ -411,27 +491,27 @@ public:
   Features();
 
   /// \c true if comments are allowed. Default: \c true.
-  bool allowComments_;
+  bool allowComments_{true};
 
   /// \c true if root must be either an array or an object value. Default: \c
   /// false.
-  bool strictRoot_;
+  bool strictRoot_{false};
 
   /// \c true if dropped null placeholders are allowed. Default: \c false.
-  bool allowDroppedNullPlaceholders_;
+  bool allowDroppedNullPlaceholders_{false};
 
   /// \c true if numeric object key are allowed. Default: \c false.
-  bool allowNumericKeys_;
+  bool allowNumericKeys_{false};
 };
 
 } // namespace Json
 
 #pragma pack(pop)
 
-#endif // CPPTL_JSON_FEATURES_H_INCLUDED
+#endif // JSON_FEATURES_H_INCLUDED
 
 // //////////////////////////////////////////////////////////////////////
-// End of content of file: include/json/features.h
+// End of content of file: include/json/json_features.h
 // //////////////////////////////////////////////////////////////////////
 
 
@@ -448,38 +528,49 @@ public:
 // recognized in your jurisdiction.
 // See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
 
-#ifndef CPPTL_JSON_H_INCLUDED
-#define CPPTL_JSON_H_INCLUDED
+#ifndef JSON_H_INCLUDED
+#define JSON_H_INCLUDED
 
 #if !defined(JSON_IS_AMALGAMATION)
 #include "forwards.h"
 #endif // if !defined(JSON_IS_AMALGAMATION)
-#include <string>
-#include <vector>
-#include <exception>
 
-#ifndef JSON_USE_CPPTL_SMALLMAP
-#include <map>
+// Conditional NORETURN attribute on the throw functions would:
+// a) suppress false positives from static code analysis
+// b) possibly improve optimization opportunities.
+#if !defined(JSONCPP_NORETURN)
+#if defined(_MSC_VER) && _MSC_VER == 1800
+#define JSONCPP_NORETURN __declspec(noreturn)
 #else
-#include <cpptl/smallmap.h>
+#define JSONCPP_NORETURN [[noreturn]]
 #endif
-#ifdef JSON_USE_CPPTL
-#include <cpptl/forwards.h>
 #endif
 
-//Conditional NORETURN attribute on the throw functions would:
-// a) suppress false positives from static code analysis
-// b) possibly improve optimization opportunities.
-#if !defined(JSONCPP_NORETURN)
-#  if defined(_MSC_VER)
-#    define JSONCPP_NORETURN __declspec(noreturn)
-#  elif defined(__GNUC__)
-#    define JSONCPP_NORETURN __attribute__ ((__noreturn__))
-#  else
-#    define JSONCPP_NORETURN
-#  endif
+// Support for '= delete' with template declarations was a late addition
+// to the c++11 standard and is rejected by clang 3.8 and Apple clang 8.2
+// even though these declare themselves to be c++11 compilers.
+#if !defined(JSONCPP_TEMPLATE_DELETE)
+#if defined(__clang__) && defined(__apple_build_version__)
+#if __apple_build_version__ <= 8000042
+#define JSONCPP_TEMPLATE_DELETE
+#endif
+#elif defined(__clang__)
+#if __clang_major__ == 3 && __clang_minor__ <= 8
+#define JSONCPP_TEMPLATE_DELETE
+#endif
+#endif
+#if !defined(JSONCPP_TEMPLATE_DELETE)
+#define JSONCPP_TEMPLATE_DELETE = delete
+#endif
 #endif
 
+#include <array>
+#include <exception>
+#include <map>
+#include <memory>
+#include <string>
+#include <vector>
+
 // Disable warning C4251: <data member>: <type> needs to have dll-interface to
 // be used by...
 #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING)
@@ -493,17 +584,19 @@ public:
  */
 namespace Json {
 
+#if JSON_USE_EXCEPTION
 /** Base class for all exceptions we throw.
  *
  * We use nothing but these internally. Of course, STL can throw others.
  */
 class JSON_API Exception : public std::exception {
 public:
-  Exception(JSONCPP_STRING const& msg);
-  ~Exception() JSONCPP_NOEXCEPT JSONCPP_OVERRIDE;
-  char const* what() const JSONCPP_NOEXCEPT JSONCPP_OVERRIDE;
+  Exception(String msg);
+  ~Exception() noexcept override;
+  char const* what() const noexcept override;
+
 protected:
-  JSONCPP_STRING msg_;
+  String msg_;
 };
 
 /** Exceptions which the user cannot easily avoid.
@@ -514,7 +607,7 @@ protected:
  */
 class JSON_API RuntimeError : public Exception {
 public:
-  RuntimeError(JSONCPP_STRING const& msg);
+  RuntimeError(String const& msg);
 };
 
 /** Exceptions thrown by JSON_ASSERT/JSON_FAIL macros.
@@ -525,13 +618,14 @@ public:
  */
 class JSON_API LogicError : public Exception {
 public:
-  LogicError(JSONCPP_STRING const& msg);
+  LogicError(String const& msg);
 };
+#endif
 
 /// used internally
-JSONCPP_NORETURN void throwRuntimeError(JSONCPP_STRING const& msg);
+JSONCPP_NORETURN void throwRuntimeError(String const& msg);
 /// used internally
-JSONCPP_NORETURN void throwLogicError(JSONCPP_STRING const& msg);
+JSONCPP_NORETURN void throwLogicError(String const& msg);
 
 /** \brief Type of the value held by a Value object.
  */
@@ -554,10 +648,12 @@ enum CommentPlacement {
   numberOfCommentPlacement
 };
 
-//# ifdef JSON_USE_CPPTL
-//   typedef CppTL::AnyEnumerator<const char *> EnumMemberNames;
-//   typedef CppTL::AnyEnumerator<const Value &> EnumValues;
-//# endif
+/** \brief Type of precision for formatting of real values.
+ */
+enum PrecisionType {
+  significantDigits = 0, ///< we set max number of significant digits in string
+  decimalPlaces          ///< we set max number of digits after "." in string
+};
 
 /** \brief Lightweight wrapper to tag static string.
  *
@@ -610,7 +706,7 @@ private:
  * The get() methods can be used to obtain default value in the case the
  * required element does not exist.
  *
- * It is possible to iterate over the list of a #objectValue values using
+ * It is possible to iterate over the list of member keys of an object using
  * the getMemberNames() method.
  *
  * \note #Value string-length fit in size_t, but keys must be < 2^30.
@@ -621,76 +717,86 @@ private:
  */
 class JSON_API Value {
   friend class ValueIteratorBase;
+
 public:
-  typedef std::vector<JSONCPP_STRING> Members;
-  typedef ValueIterator iterator;
-  typedef ValueConstIterator const_iterator;
-  typedef Json::UInt UInt;
-  typedef Json::Int Int;
+  using Members = std::vector<String>;
+  using iterator = ValueIterator;
+  using const_iterator = ValueConstIterator;
+  using UInt = Json::UInt;
+  using Int = Json::Int;
 #if defined(JSON_HAS_INT64)
-  typedef Json::UInt64 UInt64;
-  typedef Json::Int64 Int64;
+  using UInt64 = Json::UInt64;
+  using Int64 = Json::Int64;
 #endif // defined(JSON_HAS_INT64)
-  typedef Json::LargestInt LargestInt;
-  typedef Json::LargestUInt LargestUInt;
-  typedef Json::ArrayIndex ArrayIndex;
+  using LargestInt = Json::LargestInt;
+  using LargestUInt = Json::LargestUInt;
+  using ArrayIndex = Json::ArrayIndex;
 
   // Required for boost integration, e. g. BOOST_TEST
-  typedef std::string value_type;
+  using value_type = std::string;
+
+#if JSON_USE_NULLREF
+  // Binary compatibility kludges, do not use.
+  static const Value& null;
+  static const Value& nullRef;
+#endif
 
-  static const Value& null;  ///< We regret this reference to a global instance; prefer the simpler Value().
-  static const Value& nullRef;  ///< just a kludge for binary-compatibility; same as null
-  static Value const& nullSingleton(); ///< Prefer this to null or nullRef.
+  // null and nullRef are deprecated, use this instead.
+  static Value const& nullSingleton();
 
   /// Minimum signed integer value that can be stored in a Json::Value.
-  static const LargestInt minLargestInt;
+  static constexpr LargestInt minLargestInt =
+      LargestInt(~(LargestUInt(-1) / 2));
   /// Maximum signed integer value that can be stored in a Json::Value.
-  static const LargestInt maxLargestInt;
+  static constexpr LargestInt maxLargestInt = LargestInt(LargestUInt(-1) / 2);
   /// Maximum unsigned integer value that can be stored in a Json::Value.
-  static const LargestUInt maxLargestUInt;
+  static constexpr LargestUInt maxLargestUInt = LargestUInt(-1);
 
   /// Minimum signed int value that can be stored in a Json::Value.
-  static const Int minInt;
+  static constexpr Int minInt = Int(~(UInt(-1) / 2));
   /// Maximum signed int value that can be stored in a Json::Value.
-  static const Int maxInt;
+  static constexpr Int maxInt = Int(UInt(-1) / 2);
   /// Maximum unsigned int value that can be stored in a Json::Value.
-  static const UInt maxUInt;
+  static constexpr UInt maxUInt = UInt(-1);
 
 #if defined(JSON_HAS_INT64)
   /// Minimum signed 64 bits int value that can be stored in a Json::Value.
-  static const Int64 minInt64;
+  static constexpr Int64 minInt64 = Int64(~(UInt64(-1) / 2));
   /// Maximum signed 64 bits int value that can be stored in a Json::Value.
-  static const Int64 maxInt64;
+  static constexpr Int64 maxInt64 = Int64(UInt64(-1) / 2);
   /// Maximum unsigned 64 bits int value that can be stored in a Json::Value.
-  static const UInt64 maxUInt64;
+  static constexpr UInt64 maxUInt64 = UInt64(-1);
 #endif // defined(JSON_HAS_INT64)
-
+  /// Default precision for real value for string representation.
+  static constexpr UInt defaultRealPrecision = 17;
+  // The constant is hard-coded because some compiler have trouble
+  // converting Value::maxUInt64 to a double correctly (AIX/xlC).
+  // Assumes that UInt64 is a 64 bits integer.
+  static constexpr double maxUInt64AsDouble = 18446744073709551615.0;
+// Workaround for bug in the NVIDIAs CUDA 9.1 nvcc compiler
+// when using gcc and clang backend compilers.  CZString
+// cannot be defined as private.  See issue #486
+#ifdef __NVCC__
+public:
+#else
 private:
+#endif
 #ifndef JSONCPP_DOC_EXCLUDE_IMPLEMENTATION
   class CZString {
   public:
-    enum DuplicationPolicy {
-      noDuplication = 0,
-      duplicate,
-      duplicateOnCopy
-    };
+    enum DuplicationPolicy { noDuplication = 0, duplicate, duplicateOnCopy };
     CZString(ArrayIndex index);
     CZString(char const* str, unsigned length, DuplicationPolicy allocate);
     CZString(CZString const& other);
-#if JSON_HAS_RVALUE_REFERENCES
     CZString(CZString&& other);
-#endif
     ~CZString();
     CZString& operator=(const CZString& other);
-
-#if JSON_HAS_RVALUE_REFERENCES
     CZString& operator=(CZString&& other);
-#endif
 
     bool operator<(CZString const& other) const;
     bool operator==(CZString const& other) const;
     ArrayIndex index() const;
-    //const char* c_str() const; ///< \deprecated
+    // const char* c_str() const; ///< \deprecated
     char const* data() const;
     unsigned length() const;
     bool isStaticString() const;
@@ -699,11 +805,11 @@ private:
     void swap(CZString& other);
 
     struct StringStorage {
-      unsigned policy_: 2;
-      unsigned length_: 30; // 1GB max
+      unsigned policy_ : 2;
+      unsigned length_ : 30; // 1GB max
     };
 
-    char const* cstr_;  // actually, a prefixed string, unless policy is noDup
+    char const* cstr_; // actually, a prefixed string, unless policy is noDup
     union {
       ArrayIndex index_;
       StringStorage storage_;
@@ -711,29 +817,26 @@ private:
   };
 
 public:
-#ifndef JSON_USE_CPPTL_SMALLMAP
   typedef std::map<CZString, Value> ObjectValues;
-#else
-  typedef CppTL::SmallMap<CZString, Value> ObjectValues;
-#endif // ifndef JSON_USE_CPPTL_SMALLMAP
 #endif // ifndef JSONCPP_DOC_EXCLUDE_IMPLEMENTATION
 
 public:
-  /** \brief Create a default Value of the given type.
-
-    This is a very useful constructor.
-    To create an empty array, pass arrayValue.
-    To create an empty object, pass objectValue.
-    Another Value can then be set to this one by assignment.
-This is useful since clear() and resize() will not alter types.
-
-    Examples:
-\code
-Json::Value null_value; // null
-Json::Value arr_value(Json::arrayValue); // []
-Json::Value obj_value(Json::objectValue); // {}
-\endcode
-  */
+  /**
+   * \brief Create a default Value of the given type.
+   *
+   * This is a very useful constructor.
+   * To create an empty array, pass arrayValue.
+   * To create an empty object, pass objectValue.
+   * Another Value can then be set to this one by assignment.
+   * This is useful since clear() and resize() will not alter types.
+   *
+   * Examples:
+   *   \code
+   *   Json::Value null_value; // null
+   *   Json::Value arr_value(Json::arrayValue); // []
+   *   Json::Value obj_value(Json::objectValue); // {}
+   *   \endcode
+   */
   Value(ValueType type = nullValue);
   Value(Int value);
   Value(UInt value);
@@ -744,38 +847,35 @@ Json::Value obj_value(Json::objectValue); // {}
   Value(double value);
   Value(const char* value); ///< Copy til first 0. (NULL causes to seg-fault.)
   Value(const char* begin, const char* end); ///< Copy all, incl zeroes.
-  /** \brief Constructs a value from a static string.
-
+  /**
+   * \brief Constructs a value from a static string.
+   *
    * Like other value string constructor but do not duplicate the string for
-   * internal storage. The given string must remain alive after the call to this
-   * constructor.
+   * internal storage. The given string must remain alive after the call to
+   * this constructor.
+   *
    * \note This works only for null-terminated strings. (We cannot change the
-   *   size of this class, so we have nowhere to store the length,
-   *   which might be computed later for various operations.)
+   * size of this class, so we have nowhere to store the length, which might be
+   * computed later for various operations.)
    *
    * Example of usage:
-   * \code
-   * static StaticString foo("some text");
-   * Json::Value aValue(foo);
-   * \endcode
+   *   \code
+   *   static StaticString foo("some text");
+   *   Json::Value aValue(foo);
+   *   \endcode
    */
   Value(const StaticString& value);
-  Value(const JSONCPP_STRING& value); ///< Copy data() til size(). Embedded zeroes too.
-#ifdef JSON_USE_CPPTL
-  Value(const CppTL::ConstString& value);
-#endif
+  Value(const String& value);
   Value(bool value);
-  /// Deep copy.
+  Value(std::nullptr_t ptr) = delete;
   Value(const Value& other);
-#if JSON_HAS_RVALUE_REFERENCES
-  /// Move constructor
   Value(Value&& other);
-#endif
   ~Value();
 
-  /// Deep copy, then swap(other).
-  /// \note Over-write existing comments. To preserve comments, use #swapPayload().
-  Value& operator=(Value other);
+  /// \note Overwrite existing comments. To preserve comments, use
+  /// #swapPayload().
+  Value& operator=(const Value& other);
+  Value& operator=(Value&& other);
 
   /// Swap everything.
   void swap(Value& other);
@@ -800,17 +900,14 @@ Json::Value obj_value(Json::objectValue); // {}
 
   const char* asCString() const; ///< Embedded zeroes could cause you trouble!
 #if JSONCPP_USING_SECURE_MEMORY
-  unsigned getCStringLength() const; //Allows you to understand the length of the CString
+  unsigned getCStringLength() const; // Allows you to understand the length of
+                                     // the CString
 #endif
-  JSONCPP_STRING asString() const; ///< Embedded zeroes are possible.
+  String asString() const; ///< Embedded zeroes are possible.
   /** Get raw char* of string-value.
    *  \return false if !string. (Seg-fault if str or end are NULL.)
    */
-  bool getString(
-      char const** begin, char const** end) const;
-#ifdef JSON_USE_CPPTL
-  CppTL::ConstString asConstString() const;
-#endif
+  bool getString(char const** begin, char const** end) const;
   Int asInt() const;
   UInt asUInt() const;
 #if defined(JSON_HAS_INT64)
@@ -836,6 +933,10 @@ Json::Value obj_value(Json::objectValue); // {}
   bool isArray() const;
   bool isObject() const;
 
+  /// The `as<T>` and `is<T>` member function templates and specializations.
+  template <typename T> T as() const JSONCPP_TEMPLATE_DELETE;
+  template <typename T> bool is() const JSONCPP_TEMPLATE_DELETE;
+
   bool isConvertibleTo(ValueType other) const;
 
   /// Number of values in array or object
@@ -853,42 +954,33 @@ Json::Value obj_value(Json::objectValue); // {}
   /// \post type() is unchanged
   void clear();
 
-  /// Resize the array to size elements.
+  /// Resize the array to newSize elements.
   /// New elements are initialized to null.
   /// May only be called on nullValue or arrayValue.
   /// \pre type() is arrayValue or nullValue
   /// \post type() is arrayValue
-  void resize(ArrayIndex size);
+  void resize(ArrayIndex newSize);
 
-  /// Access an array element (zero based index ).
-  /// If the array contains less than index element, then null value are
-  /// inserted
-  /// in the array so that its size is index+1.
+  //@{
+  /// Access an array element (zero based index). If the array contains less
+  /// than index element, then null value are inserted in the array so that
+  /// its size is index+1.
   /// (You may need to say 'value[0u]' to get your compiler to distinguish
-  ///  this from the operator[] which takes a string.)
+  /// this from the operator[] which takes a string.)
   Value& operator[](ArrayIndex index);
-
-  /// Access an array element (zero based index ).
-  /// If the array contains less than index element, then null value are
-  /// inserted
-  /// in the array so that its size is index+1.
-  /// (You may need to say 'value[0u]' to get your compiler to distinguish
-  ///  this from the operator[] which takes a string.)
   Value& operator[](int index);
+  //@}
 
-  /// Access an array element (zero based index )
+  //@{
+  /// Access an array element (zero based index).
   /// (You may need to say 'value[0u]' to get your compiler to distinguish
-  ///  this from the operator[] which takes a string.)
+  /// this from the operator[] which takes a string.)
   const Value& operator[](ArrayIndex index) const;
-
-  /// Access an array element (zero based index )
-  /// (You may need to say 'value[0u]' to get your compiler to distinguish
-  ///  this from the operator[] which takes a string.)
   const Value& operator[](int index) const;
+  //@}
 
   /// If the array contains at least index+1 elements, returns the element
-  /// value,
-  /// otherwise returns defaultValue.
+  /// value, otherwise returns defaultValue.
   Value get(ArrayIndex index, const Value& defaultValue) const;
   /// Return true if index < size().
   bool isValidIndex(ArrayIndex index) const;
@@ -896,61 +988,51 @@ Json::Value obj_value(Json::objectValue); // {}
   ///
   /// Equivalent to jsonvalue[jsonvalue.size()] = value;
   Value& append(const Value& value);
-
-#if JSON_HAS_RVALUE_REFERENCES
   Value& append(Value&& value);
-#endif
+
+  /// \brief Insert value in array at specific index
+  bool insert(ArrayIndex index, const Value& newValue);
+  bool insert(ArrayIndex index, Value&& newValue);
 
   /// Access an object value by name, create a null member if it does not exist.
   /// \note Because of our implementation, keys are limited to 2^30 -1 chars.
-  ///  Exceeding that will cause an exception.
+  /// Exceeding that will cause an exception.
   Value& operator[](const char* key);
   /// Access an object value by name, returns null if there is no member with
   /// that name.
   const Value& operator[](const char* key) const;
   /// Access an object value by name, create a null member if it does not exist.
   /// \param key may contain embedded nulls.
-  Value& operator[](const JSONCPP_STRING& key);
+  Value& operator[](const String& key);
   /// Access an object value by name, returns null if there is no member with
   /// that name.
   /// \param key may contain embedded nulls.
-  const Value& operator[](const JSONCPP_STRING& key) const;
+  const Value& operator[](const String& key) const;
   /** \brief Access an object value by name, create a null member if it does not
-   exist.
-
-   * If the object has no entry for that name, then the member name used to store
-   * the new entry is not duplicated.
+   * exist.
+   *
+   * If the object has no entry for that name, then the member name used to
+   * store the new entry is not duplicated.
    * Example of use:
-   * \code
-   * Json::Value object;
-   * static const StaticString code("code");
-   * object[code] = 1234;
-   * \endcode
+   *   \code
+   *   Json::Value object;
+   *   static const StaticString code("code");
+   *   object[code] = 1234;
+   *   \endcode
    */
   Value& operator[](const StaticString& key);
-#ifdef JSON_USE_CPPTL
-  /// Access an object value by name, create a null member if it does not exist.
-  Value& operator[](const CppTL::ConstString& key);
-  /// Access an object value by name, returns null if there is no member with
-  /// that name.
-  const Value& operator[](const CppTL::ConstString& key) const;
-#endif
   /// Return the member named key if it exist, defaultValue otherwise.
   /// \note deep copy
   Value get(const char* key, const Value& defaultValue) const;
   /// Return the member named key if it exist, defaultValue otherwise.
   /// \note deep copy
   /// \note key may contain embedded nulls.
-  Value get(const char* begin, const char* end, const Value& defaultValue) const;
+  Value get(const char* begin, const char* end,
+            const Value& defaultValue) const;
   /// Return the member named key if it exist, defaultValue otherwise.
   /// \note deep copy
   /// \param key may contain embedded nulls.
-  Value get(const JSONCPP_STRING& key, const Value& defaultValue) const;
-#ifdef JSON_USE_CPPTL
-  /// Return the member named key if it exist, defaultValue otherwise.
-  /// \note deep copy
-  Value get(const CppTL::ConstString& key, const Value& defaultValue) const;
-#endif
+  Value get(const String& key, const Value& defaultValue) const;
   /// Most general and efficient version of isMember()const, get()const,
   /// and operator[]const
   /// \note As stated elsewhere, behavior is undefined if (end-begin) >= 2^30
@@ -958,51 +1040,44 @@ Json::Value obj_value(Json::objectValue); // {}
   /// Most general and efficient version of object-mutators.
   /// \note As stated elsewhere, behavior is undefined if (end-begin) >= 2^30
   /// \return non-zero, but JSON_ASSERT if this is neither object nor nullValue.
-  Value const* demand(char const* begin, char const* end);
+  Value* demand(char const* begin, char const* end);
   /// \brief Remove and return the named member.
   ///
   /// Do nothing if it did not exist.
-  /// \return the removed Value, or null.
   /// \pre type() is objectValue or nullValue
   /// \post type() is unchanged
-  /// \deprecated
   void removeMember(const char* key);
   /// Same as removeMember(const char*)
   /// \param key may contain embedded nulls.
-  /// \deprecated
-  void removeMember(const JSONCPP_STRING& key);
+  void removeMember(const String& key);
   /// Same as removeMember(const char* begin, const char* end, Value* removed),
   /// but 'key' is null-terminated.
   bool removeMember(const char* key, Value* removed);
   /** \brief Remove the named map member.
-
-      Update 'removed' iff removed.
-      \param key may contain embedded nulls.
-      \return true iff removed (no exceptions)
-  */
-  bool removeMember(JSONCPP_STRING const& key, Value* removed);
-  /// Same as removeMember(JSONCPP_STRING const& key, Value* removed)
+   *
+   *  Update 'removed' iff removed.
+   *  \param key may contain embedded nulls.
+   *  \return true iff removed (no exceptions)
+   */
+  bool removeMember(String const& key, Value* removed);
+  /// Same as removeMember(String const& key, Value* removed)
   bool removeMember(const char* begin, const char* end, Value* removed);
   /** \brief Remove the indexed array element.
-
-      O(n) expensive operations.
-      Update 'removed' iff removed.
-      \return true iff removed (no exceptions)
-  */
-  bool removeIndex(ArrayIndex i, Value* removed);
+   *
+   *  O(n) expensive operations.
+   *  Update 'removed' iff removed.
+   *  \return true if removed (no exceptions)
+   */
+  bool removeIndex(ArrayIndex index, Value* removed);
 
   /// Return true if the object has a member named key.
   /// \note 'key' must be null-terminated.
   bool isMember(const char* key) const;
   /// Return true if the object has a member named key.
   /// \param key may contain embedded nulls.
-  bool isMember(const JSONCPP_STRING& key) const;
-  /// Same as isMember(JSONCPP_STRING const& key)const
+  bool isMember(const String& key) const;
+  /// Same as isMember(String const& key)const
   bool isMember(const char* begin, const char* end) const;
-#ifdef JSON_USE_CPPTL
-  /// Return true if the object has a member named key.
-  bool isMember(const CppTL::ConstString& key) const;
-#endif
 
   /// \brief Return a list of the member names.
   ///
@@ -1011,23 +1086,22 @@ Json::Value obj_value(Json::objectValue); // {}
   /// \post if type() was nullValue, it remains nullValue
   Members getMemberNames() const;
 
-  //# ifdef JSON_USE_CPPTL
-  //      EnumMemberNames enumMemberNames() const;
-  //      EnumValues enumValues() const;
-  //# endif
-
   /// \deprecated Always pass len.
-  JSONCPP_DEPRECATED("Use setComment(JSONCPP_STRING const&) instead.")
-  void setComment(const char* comment, CommentPlacement placement);
+  JSONCPP_DEPRECATED("Use setComment(String const&) instead.")
+  void setComment(const char* comment, CommentPlacement placement) {
+    setComment(String(comment, strlen(comment)), placement);
+  }
   /// Comments must be //... or /* ... */
-  void setComment(const char* comment, size_t len, CommentPlacement placement);
+  void setComment(const char* comment, size_t len, CommentPlacement placement) {
+    setComment(String(comment, len), placement);
+  }
   /// Comments must be //... or /* ... */
-  void setComment(const JSONCPP_STRING& comment, CommentPlacement placement);
+  void setComment(String comment, CommentPlacement placement);
   bool hasComment(CommentPlacement placement) const;
   /// Include delimiters and embedded newlines.
-  JSONCPP_STRING getComment(CommentPlacement placement) const;
+  String getComment(CommentPlacement placement) const;
 
-  JSONCPP_STRING toStyledString() const;
+  String toStyledString() const;
 
   const_iterator begin() const;
   const_iterator end() const;
@@ -1043,20 +1117,20 @@ Json::Value obj_value(Json::objectValue); // {}
   ptrdiff_t getOffsetLimit() const;
 
 private:
+  void setType(ValueType v) {
+    bits_.value_type_ = static_cast<unsigned char>(v);
+  }
+  bool isAllocated() const { return bits_.allocated_; }
+  void setIsAllocated(bool v) { bits_.allocated_ = v; }
+
   void initBasic(ValueType type, bool allocated = false);
+  void dupPayload(const Value& other);
+  void releasePayload();
+  void dupMeta(const Value& other);
 
   Value& resolveReference(const char* key);
   Value& resolveReference(const char* key, const char* end);
 
-  struct CommentInfo {
-    CommentInfo();
-    ~CommentInfo();
-
-    void setComment(const char* text, size_t len);
-
-    char* comment_;
-  };
-
   // struct MemberNamesTransform
   //{
   //   typedef const char *result_type;
@@ -1071,13 +1145,33 @@ private:
     LargestUInt uint_;
     double real_;
     bool bool_;
-    char* string_;  // actually ptr to unsigned, followed by str, unless !allocated_
+    char* string_; // if allocated_, ptr to { unsigned, char[] }.
     ObjectValues* map_;
   } value_;
-  ValueType type_ : 8;
-  unsigned int allocated_ : 1; // Notes: if declared as bool, bitfield is useless.
-                               // If not allocated_, string_ must be null-terminated.
-  CommentInfo* comments_;
+
+  struct {
+    // Really a ValueType, but types should agree for bitfield packing.
+    unsigned int value_type_ : 8;
+    // Unless allocated_, string_ must be null-terminated.
+    unsigned int allocated_ : 1;
+  } bits_;
+
+  class Comments {
+  public:
+    Comments() = default;
+    Comments(const Comments& that);
+    Comments(Comments&& that);
+    Comments& operator=(const Comments& that);
+    Comments& operator=(Comments&& that);
+    bool has(CommentPlacement slot) const;
+    String get(CommentPlacement slot) const;
+    void set(CommentPlacement slot, String comment);
+
+  private:
+    using Array = std::array<String, numberOfCommentPlacement>;
+    std::unique_ptr<Array> ptr_;
+  };
+  Comments comments_;
 
   // [start, limit) byte offsets in the source JSON text from which this Value
   // was extracted.
@@ -1085,6 +1179,36 @@ private:
   ptrdiff_t limit_;
 };
 
+template <> inline bool Value::as<bool>() const { return asBool(); }
+template <> inline bool Value::is<bool>() const { return isBool(); }
+
+template <> inline Int Value::as<Int>() const { return asInt(); }
+template <> inline bool Value::is<Int>() const { return isInt(); }
+
+template <> inline UInt Value::as<UInt>() const { return asUInt(); }
+template <> inline bool Value::is<UInt>() const { return isUInt(); }
+
+#if defined(JSON_HAS_INT64)
+template <> inline Int64 Value::as<Int64>() const { return asInt64(); }
+template <> inline bool Value::is<Int64>() const { return isInt64(); }
+
+template <> inline UInt64 Value::as<UInt64>() const { return asUInt64(); }
+template <> inline bool Value::is<UInt64>() const { return isUInt64(); }
+#endif
+
+template <> inline double Value::as<double>() const { return asDouble(); }
+template <> inline bool Value::is<double>() const { return isDouble(); }
+
+template <> inline String Value::as<String>() const { return asString(); }
+template <> inline bool Value::is<String>() const { return isString(); }
+
+/// These `as` specializations are type conversions, and do not have a
+/// corresponding `is`.
+template <> inline float Value::as<float>() const { return asFloat(); }
+template <> inline const char* Value::as<const char*>() const {
+  return asCString();
+}
+
 /** \brief Experimental and untested: represents an element of the "path" to
  * access a node.
  */
@@ -1095,17 +1219,13 @@ public:
   PathArgument();
   PathArgument(ArrayIndex index);
   PathArgument(const char* key);
-  PathArgument(const JSONCPP_STRING& key);
+  PathArgument(String key);
 
 private:
-  enum Kind {
-    kindNone = 0,
-    kindIndex,
-    kindKey
-  };
-  JSONCPP_STRING key_;
-  ArrayIndex index_;
-  Kind kind_;
+  enum Kind { kindNone = 0, kindIndex, kindKey };
+  String key_;
+  ArrayIndex index_{};
+  Kind kind_{kindNone};
 };
 
 /** \brief Experimental and untested: represents a "path" to access a node.
@@ -1117,12 +1237,11 @@ private:
  * - ".name1.name2.name3"
  * - ".[0][1][2].name1[3]"
  * - ".%" => member name is provided as parameter
- * - ".[%]" => index is provied as parameter
+ * - ".[%]" => index is provided as parameter
  */
 class JSON_API Path {
 public:
-  Path(const JSONCPP_STRING& path,
-       const PathArgument& a1 = PathArgument(),
+  Path(const String& path, const PathArgument& a1 = PathArgument(),
        const PathArgument& a2 = PathArgument(),
        const PathArgument& a3 = PathArgument(),
        const PathArgument& a4 = PathArgument(),
@@ -1135,15 +1254,13 @@ public:
   Value& make(Value& root) const;
 
 private:
-  typedef std::vector<const PathArgument*> InArgs;
-  typedef std::vector<PathArgument> Args;
+  using InArgs = std::vector<const PathArgument*>;
+  using Args = std::vector<PathArgument>;
 
-  void makePath(const JSONCPP_STRING& path, const InArgs& in);
-  void addPathInArg(const JSONCPP_STRING& path,
-                    const InArgs& in,
-                    InArgs::const_iterator& itInArg,
-                    PathArgument::Kind kind);
-  void invalidPath(const JSONCPP_STRING& path, int location);
+  void makePath(const String& path, const InArgs& in);
+  void addPathInArg(const String& path, const InArgs& in,
+                    InArgs::const_iterator& itInArg, PathArgument::Kind kind);
+  static void invalidPath(const String& path, int location);
 
   Args args_;
 };
@@ -1153,10 +1270,10 @@ private:
  */
 class JSON_API ValueIteratorBase {
 public:
-  typedef std::bidirectional_iterator_tag iterator_category;
-  typedef unsigned int size_t;
-  typedef int difference_type;
-  typedef ValueIteratorBase SelfType;
+  using iterator_category = std::bidirectional_iterator_tag;
+  using size_t = unsigned int;
+  using difference_type = int;
+  using SelfType = ValueIteratorBase;
 
   bool operator==(const SelfType& other) const { return isEqual(other); }
 
@@ -1170,17 +1287,19 @@ public:
   /// Value.
   Value key() const;
 
-  /// Return the index of the referenced Value, or -1 if it is not an arrayValue.
+  /// Return the index of the referenced Value, or -1 if it is not an
+  /// arrayValue.
   UInt index() const;
 
   /// Return the member name of the referenced Value, or "" if it is not an
   /// objectValue.
   /// \note Avoid `c_str()` on result, as embedded zeroes are possible.
-  JSONCPP_STRING name() const;
+  String name() const;
 
   /// Return the member name of the referenced Value. "" if it is not an
   /// objectValue.
-  /// \deprecated This cannot be used for UTF-8 strings, since there can be embedded nulls.
+  /// \deprecated This cannot be used for UTF-8 strings, since there can be
+  /// embedded nulls.
   JSONCPP_DEPRECATED("Use `key = name();` instead.")
   char const* memberName() const;
   /// Return the member name of the referenced Value, or NULL if it is not an
@@ -1189,7 +1308,14 @@ public:
   char const* memberName(char const** end) const;
 
 protected:
-  Value& deref() const;
+  /*! Internal utility functions to assist with implementing
+   *   other iterator functions. The const and non-const versions
+   *   of the "deref" protected methods expose the protected
+   *   current_ member variable in a way that can often be
+   *   optimized away by the compiler.
+   */
+  const Value& deref() const;
+  Value& deref();
 
   void increment();
 
@@ -1204,7 +1330,7 @@ protected:
 private:
   Value::ObjectValues::iterator current_;
   // Indicates that iterator is for a null value.
-  bool isNull_;
+  bool isNull_{true};
 
 public:
   // For some reason, BORLAND needs these at the end, rather
@@ -1220,20 +1346,21 @@ class JSON_API ValueConstIterator : public ValueIteratorBase {
   friend class Value;
 
 public:
-  typedef const Value value_type;
-  //typedef unsigned int size_t;
-  //typedef int difference_type;
-  typedef const Value& reference;
-  typedef const Value* pointer;
-  typedef ValueConstIterator SelfType;
+  using value_type = const Value;
+  // typedef unsigned int size_t;
+  // typedef int difference_type;
+  using reference = const Value&;
+  using pointer = const Value*;
+  using SelfType = ValueConstIterator;
 
   ValueConstIterator();
   ValueConstIterator(ValueIterator const& other);
 
 private:
-/*! \internal Use by Value to create an iterator.
- */
+  /*! \internal Use by Value to create an iterator.
+   */
   explicit ValueConstIterator(const Value::ObjectValues::iterator& current);
+
 public:
   SelfType& operator=(const ValueIteratorBase& other);
 
@@ -1270,21 +1397,22 @@ class JSON_API ValueIterator : public ValueIteratorBase {
   friend class Value;
 
 public:
-  typedef Value value_type;
-  typedef unsigned int size_t;
-  typedef int difference_type;
-  typedef Value& reference;
-  typedef Value* pointer;
-  typedef ValueIterator SelfType;
+  using value_type = Value;
+  using size_t = unsigned int;
+  using difference_type = int;
+  using reference = Value&;
+  using pointer = Value*;
+  using SelfType = ValueIterator;
 
   ValueIterator();
   explicit ValueIterator(const ValueConstIterator& other);
   ValueIterator(const ValueIterator& other);
 
 private:
-/*! \internal Use by Value to create an iterator.
- */
+  /*! \internal Use by Value to create an iterator.
+   */
   explicit ValueIterator(const Value::ObjectValues::iterator& current);
+
 public:
   SelfType& operator=(const SelfType& other);
 
@@ -1310,19 +1438,18 @@ public:
     return *this;
   }
 
-  reference operator*() const { return deref(); }
-
-  pointer operator->() const { return &deref(); }
+  /*! The return value of non-const iterators can be
+   *  changed, so the these functions are not const
+   *  because the returned references/pointers can be used
+   *  to change state of the base class.
+   */
+  reference operator*() { return deref(); }
+  pointer operator->() { return &deref(); }
 };
 
-} // namespace Json
-
+inline void swap(Value& a, Value& b) { a.swap(b); }
 
-namespace std {
-/// Specialize std::swap() for Json::Value.
-template<>
-inline void swap(Json::Value& a, Json::Value& b) { a.swap(b); }
-}
+} // namespace Json
 
 #pragma pack(pop)
 
@@ -1330,7 +1457,7 @@ inline void swap(Json::Value& a, Json::Value& b) { a.swap(b); }
 #pragma warning(pop)
 #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING)
 
-#endif // CPPTL_JSON_H_INCLUDED
+#endif // JSON_H_INCLUDED
 
 // //////////////////////////////////////////////////////////////////////
 // End of content of file: include/json/value.h
@@ -1350,18 +1477,18 @@ inline void swap(Json::Value& a, Json::Value& b) { a.swap(b); }
 // recognized in your jurisdiction.
 // See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
 
-#ifndef CPPTL_JSON_READER_H_INCLUDED
-#define CPPTL_JSON_READER_H_INCLUDED
+#ifndef JSON_READER_H_INCLUDED
+#define JSON_READER_H_INCLUDED
 
 #if !defined(JSON_IS_AMALGAMATION)
-#include "features.h"
+#include "json_features.h"
 #include "value.h"
 #endif // if !defined(JSON_IS_AMALGAMATION)
 #include <deque>
 #include <iosfwd>
+#include <istream>
 #include <stack>
 #include <string>
-#include <istream>
 
 // Disable warning C4251: <data member>: <type> needs to have dll-interface to
 // be used by...
@@ -1375,132 +1502,130 @@ inline void swap(Json::Value& a, Json::Value& b) { a.swap(b); }
 namespace Json {
 
 /** \brief Unserialize a <a HREF="http://www.json.org">JSON</a> document into a
- *Value.
+ * Value.
  *
  * \deprecated Use CharReader and CharReaderBuilder.
  */
-class JSONCPP_DEPRECATED("Use CharReader and CharReaderBuilder instead") JSON_API Reader {
+
+class JSONCPP_DEPRECATED(
+    "Use CharReader and CharReaderBuilder instead.") JSON_API Reader {
 public:
-  typedef char Char;
-  typedef const Char* Location;
+  using Char = char;
+  using Location = const Char*;
 
   /** \brief An error tagged with where in the JSON text it was encountered.
    *
    * The offsets give the [start, limit) range of bytes within the text. Note
    * that this is bytes, not codepoints.
-   *
    */
   struct StructuredError {
     ptrdiff_t offset_start;
     ptrdiff_t offset_limit;
-    JSONCPP_STRING message;
+    String message;
   };
 
-  /** \brief Constructs a Reader allowing all features
-   * for parsing.
+  /** \brief Constructs a Reader allowing all features for parsing.
    */
+  JSONCPP_DEPRECATED("Use CharReader and CharReaderBuilder instead")
   Reader();
 
-  /** \brief Constructs a Reader allowing the specified feature set
-   * for parsing.
+  /** \brief Constructs a Reader allowing the specified feature set for parsing.
    */
+  JSONCPP_DEPRECATED("Use CharReader and CharReaderBuilder instead")
   Reader(const Features& features);
 
   /** \brief Read a Value from a <a HREF="http://www.json.org">JSON</a>
    * document.
-   * \param document UTF-8 encoded string containing the document to read.
-   * \param root [out] Contains the root value of the document if it was
-   *             successfully parsed.
-   * \param collectComments \c true to collect comment and allow writing them
-   * back during
-   *                        serialization, \c false to discard comments.
-   *                        This parameter is ignored if
-   * Features::allowComments_
-   *                        is \c false.
+   *
+   * \param      document        UTF-8 encoded string containing the document
+   *                             to read.
+   * \param[out] root            Contains the root value of the document if it
+   *                             was successfully parsed.
+   * \param      collectComments \c true to collect comment and allow writing
+   *                             them back during serialization, \c false to
+   *                             discard comments.  This parameter is ignored
+   *                             if Features::allowComments_ is \c false.
    * \return \c true if the document was successfully parsed, \c false if an
    * error occurred.
    */
-  bool
-  parse(const std::string& document, Value& root, bool collectComments = true);
+  bool parse(const std::string& document, Value& root,
+             bool collectComments = true);
 
   /** \brief Read a Value from a <a HREF="http://www.json.org">JSON</a>
-   document.
-   * \param beginDoc Pointer on the beginning of the UTF-8 encoded string of the
-   document to read.
-   * \param endDoc Pointer on the end of the UTF-8 encoded string of the
-   document to read.
-   *               Must be >= beginDoc.
-   * \param root [out] Contains the root value of the document if it was
-   *             successfully parsed.
-   * \param collectComments \c true to collect comment and allow writing them
-   back during
-   *                        serialization, \c false to discard comments.
-   *                        This parameter is ignored if
-   Features::allowComments_
-   *                        is \c false.
+   * document.
+   *
+   * \param      beginDoc        Pointer on the beginning of the UTF-8 encoded
+   *                             string of the document to read.
+   * \param      endDoc          Pointer on the end of the UTF-8 encoded string
+   *                             of the document to read.  Must be >= beginDoc.
+   * \param[out] root            Contains the root value of the document if it
+   *                             was successfully parsed.
+   * \param      collectComments \c true to collect comment and allow writing
+   *                             them back during serialization, \c false to
+   *                             discard comments.  This parameter is ignored
+   *                             if Features::allowComments_ is \c false.
    * \return \c true if the document was successfully parsed, \c false if an
-   error occurred.
+   * error occurred.
    */
-  bool parse(const char* beginDoc,
-             const char* endDoc,
-             Value& root,
+  bool parse(const char* beginDoc, const char* endDoc, Value& root,
              bool collectComments = true);
 
   /// \brief Parse from input stream.
   /// \see Json::operator>>(std::istream&, Json::Value&).
-  bool parse(JSONCPP_ISTREAM& is, Value& root, bool collectComments = true);
+  bool parse(IStream& is, Value& root, bool collectComments = true);
 
   /** \brief Returns a user friendly string that list errors in the parsed
    * document.
-   * \return Formatted error message with the list of errors with their location
-   * in
-   *         the parsed document. An empty string is returned if no error
-   * occurred
-   *         during parsing.
+   *
+   * \return Formatted error message with the list of errors with their
+   * location in the parsed document. An empty string is returned if no error
+   * occurred during parsing.
    * \deprecated Use getFormattedErrorMessages() instead (typo fix).
    */
   JSONCPP_DEPRECATED("Use getFormattedErrorMessages() instead.")
-  JSONCPP_STRING getFormatedErrorMessages() const;
+  String getFormatedErrorMessages() const;
 
   /** \brief Returns a user friendly string that list errors in the parsed
    * document.
-   * \return Formatted error message with the list of errors with their location
-   * in
-   *         the parsed document. An empty string is returned if no error
-   * occurred
-   *         during parsing.
+   *
+   * \return Formatted error message with the list of errors with their
+   * location in the parsed document. An empty string is returned if no error
+   * occurred during parsing.
    */
-  JSONCPP_STRING getFormattedErrorMessages() const;
+  String getFormattedErrorMessages() const;
 
-  /** \brief Returns a vector of structured erros encounted while parsing.
+  /** \brief Returns a vector of structured errors encountered while parsing.
+   *
    * \return A (possibly empty) vector of StructuredError objects. Currently
-   *         only one error can be returned, but the caller should tolerate
-   * multiple
-   *         errors.  This can occur if the parser recovers from a non-fatal
-   *         parse error and then encounters additional errors.
+   * only one error can be returned, but the caller should tolerate multiple
+   * errors.  This can occur if the parser recovers from a non-fatal parse
+   * error and then encounters additional errors.
    */
   std::vector<StructuredError> getStructuredErrors() const;
 
   /** \brief Add a semantic error message.
-   * \param value JSON Value location associated with the error
+   *
+   * \param value   JSON Value location associated with the error
    * \param message The error message.
-   * \return \c true if the error was successfully added, \c false if the
-   * Value offset exceeds the document size.
+   * \return \c true if the error was successfully added, \c false if the Value
+   * offset exceeds the document size.
    */
-  bool pushError(const Value& value, const JSONCPP_STRING& message);
+  bool pushError(const Value& value, const String& message);
 
   /** \brief Add a semantic error message with extra context.
-   * \param value JSON Value location associated with the error
+   *
+   * \param value   JSON Value location associated with the error
    * \param message The error message.
-   * \param extra Additional JSON Value location to contextualize the error
+   * \param extra   Additional JSON Value location to contextualize the error
    * \return \c true if the error was successfully added, \c false if either
    * Value offset exceeds the document size.
    */
-  bool pushError(const Value& value, const JSONCPP_STRING& message, const Value& extra);
+  bool pushError(const Value& value, const String& message, const Value& extra);
 
   /** \brief Return whether there are any errors.
-   * \return \c true if there are no errors to report \c false if
-   * errors have occurred.
+   *
+   * \return \c true if there are no errors to report \c false if errors have
+   * occurred.
    */
   bool good() const;
 
@@ -1532,15 +1657,15 @@ private:
   class ErrorInfo {
   public:
     Token token_;
-    JSONCPP_STRING message_;
+    String message_;
     Location extra_;
   };
 
-  typedef std::deque<ErrorInfo> Errors;
+  using Errors = std::deque<ErrorInfo>;
 
   bool readToken(Token& token);
   void skipSpaces();
-  bool match(Location pattern, int patternLength);
+  bool match(const Char* pattern, int patternLength);
   bool readComment();
   bool readCStyleComment();
   bool readCppStyleComment();
@@ -1552,142 +1677,138 @@ private:
   bool decodeNumber(Token& token);
   bool decodeNumber(Token& token, Value& decoded);
   bool decodeString(Token& token);
-  bool decodeString(Token& token, JSONCPP_STRING& decoded);
+  bool decodeString(Token& token, String& decoded);
   bool decodeDouble(Token& token);
   bool decodeDouble(Token& token, Value& decoded);
-  bool decodeUnicodeCodePoint(Token& token,
-                              Location& current,
-                              Location end,
+  bool decodeUnicodeCodePoint(Token& token, Location& current, Location end,
                               unsigned int& unicode);
-  bool decodeUnicodeEscapeSequence(Token& token,
-                                   Location& current,
-                                   Location end,
-                                   unsigned int& unicode);
-  bool addError(const JSONCPP_STRING& message, Token& token, Location extra = 0);
+  bool decodeUnicodeEscapeSequence(Token& token, Location& current,
+                                   Location end, unsigned int& unicode);
+  bool addError(const String& message, Token& token, Location extra = nullptr);
   bool recoverFromError(TokenType skipUntilToken);
-  bool addErrorAndRecover(const JSONCPP_STRING& message,
-                          Token& token,
+  bool addErrorAndRecover(const String& message, Token& token,
                           TokenType skipUntilToken);
   void skipUntilSpace();
   Value& currentValue();
   Char getNextChar();
-  void
-  getLocationLineAndColumn(Location location, int& line, int& column) const;
-  JSONCPP_STRING getLocationLineAndColumn(Location location) const;
+  void getLocationLineAndColumn(Location location, int& line,
+                                int& column) const;
+  String getLocationLineAndColumn(Location location) const;
   void addComment(Location begin, Location end, CommentPlacement placement);
   void skipCommentTokens(Token& token);
 
   static bool containsNewLine(Location begin, Location end);
-  static JSONCPP_STRING normalizeEOL(Location begin, Location end);
+  static String normalizeEOL(Location begin, Location end);
 
-  typedef std::stack<Value*> Nodes;
+  using Nodes = std::stack<Value*>;
   Nodes nodes_;
   Errors errors_;
-  JSONCPP_STRING document_;
-  Location begin_;
-  Location end_;
-  Location current_;
-  Location lastValueEnd_;
-  Value* lastValue_;
-  JSONCPP_STRING commentsBefore_;
+  String document_;
+  Location begin_{};
+  Location end_{};
+  Location current_{};
+  Location lastValueEnd_{};
+  Value* lastValue_{};
+  String commentsBefore_;
   Features features_;
-  bool collectComments_;
-};  // Reader
+  bool collectComments_{};
+}; // Reader
 
 /** Interface for reading JSON from a char array.
  */
 class JSON_API CharReader {
 public:
-  virtual ~CharReader() {}
+  virtual ~CharReader() = default;
   /** \brief Read a Value from a <a HREF="http://www.json.org">JSON</a>
-   document.
-   * The document must be a UTF-8 encoded string containing the document to read.
+   * document. The document must be a UTF-8 encoded string containing the
+   * document to read.
    *
-   * \param beginDoc Pointer on the beginning of the UTF-8 encoded string of the
-   document to read.
-   * \param endDoc Pointer on the end of the UTF-8 encoded string of the
-   document to read.
-   *        Must be >= beginDoc.
-   * \param root [out] Contains the root value of the document if it was
-   *             successfully parsed.
-   * \param errs [out] Formatted error messages (if not NULL)
-   *        a user friendly string that lists errors in the parsed
-   * document.
+   * \param      beginDoc Pointer on the beginning of the UTF-8 encoded string
+   *                      of the document to read.
+   * \param      endDoc   Pointer on the end of the UTF-8 encoded string of the
+   *                      document to read. Must be >= beginDoc.
+   * \param[out] root     Contains the root value of the document if it was
+   *                      successfully parsed.
+   * \param[out] errs     Formatted error messages (if not NULL) a user
+   *                      friendly string that lists errors in the parsed
+   *                      document.
    * \return \c true if the document was successfully parsed, \c false if an
-   error occurred.
+   * error occurred.
    */
-  virtual bool parse(
-      char const* beginDoc, char const* endDoc,
-      Value* root, JSONCPP_STRING* errs) = 0;
+  virtual bool parse(char const* beginDoc, char const* endDoc, Value* root,
+                     String* errs) = 0;
 
   class JSON_API Factory {
   public:
-    virtual ~Factory() {}
+    virtual ~Factory() = default;
     /** \brief Allocate a CharReader via operator new().
      * \throw std::exception if something goes wrong (e.g. invalid settings)
      */
     virtual CharReader* newCharReader() const = 0;
-  };  // Factory
-};  // CharReader
+  }; // Factory
+};   // CharReader
 
 /** \brief Build a CharReader implementation.
-
-Usage:
-\code
-  using namespace Json;
-  CharReaderBuilder builder;
-  builder["collectComments"] = false;
-  Value value;
-  JSONCPP_STRING errs;
-  bool ok = parseFromStream(builder, std::cin, &value, &errs);
-\endcode
-*/
+ *
+ * Usage:
+ *   \code
+ *   using namespace Json;
+ *   CharReaderBuilder builder;
+ *   builder["collectComments"] = false;
+ *   Value value;
+ *   String errs;
+ *   bool ok = parseFromStream(builder, std::cin, &value, &errs);
+ *   \endcode
+ */
 class JSON_API CharReaderBuilder : public CharReader::Factory {
 public:
   // Note: We use a Json::Value so that we can add data-members to this class
   // without a major version bump.
   /** Configuration of this builder.
-    These are case-sensitive.
-    Available settings (case-sensitive):
-    - `"collectComments": false or true`
-      - true to collect comment and allow writing them
-        back during serialization, false to discard comments.
-        This parameter is ignored if allowComments is false.
-    - `"allowComments": false or true`
-      - true if comments are allowed.
-    - `"strictRoot": false or true`
-      - true if root must be either an array or an object value
-    - `"allowDroppedNullPlaceholders": false or true`
-      - true if dropped null placeholders are allowed. (See StreamWriterBuilder.)
-    - `"allowNumericKeys": false or true`
-      - true if numeric object keys are allowed.
-    - `"allowSingleQuotes": false or true`
-      - true if '' are allowed for strings (both keys and values)
-    - `"stackLimit": integer`
-      - Exceeding stackLimit (recursive depth of `readValue()`) will
-        cause an exception.
-      - This is a security issue (seg-faults caused by deeply nested JSON),
-        so the default is low.
-    - `"failIfExtra": false or true`
-      - If true, `parse()` returns false when extra non-whitespace trails
-        the JSON value in the input string.
-    - `"rejectDupKeys": false or true`
-      - If true, `parse()` returns false when a key is duplicated within an object.
-    - `"allowSpecialFloats": false or true`
-      - If true, special float values (NaNs and infinities) are allowed 
-        and their values are lossfree restorable.
-
-    You can examine 'settings_` yourself
-    to see the defaults. You can also write and read them just like any
-    JSON Value.
-    \sa setDefaults()
-    */
+   * These are case-sensitive.
+   * Available settings (case-sensitive):
+   * - `"collectComments": false or true`
+   *   - true to collect comment and allow writing them back during
+   *     serialization, false to discard comments.  This parameter is ignored
+   *     if allowComments is false.
+   * - `"allowComments": false or true`
+   *   - true if comments are allowed.
+   * - `"allowTrailingCommas": false or true`
+   *   - true if trailing commas in objects and arrays are allowed.
+   * - `"strictRoot": false or true`
+   *   - true if root must be either an array or an object value
+   * - `"allowDroppedNullPlaceholders": false or true`
+   *   - true if dropped null placeholders are allowed. (See
+   *     StreamWriterBuilder.)
+   * - `"allowNumericKeys": false or true`
+   *   - true if numeric object keys are allowed.
+   * - `"allowSingleQuotes": false or true`
+   *   - true if '' are allowed for strings (both keys and values)
+   * - `"stackLimit": integer`
+   *   - Exceeding stackLimit (recursive depth of `readValue()`) will cause an
+   *     exception.
+   *   - This is a security issue (seg-faults caused by deeply nested JSON), so
+   *     the default is low.
+   * - `"failIfExtra": false or true`
+   *   - If true, `parse()` returns false when extra non-whitespace trails the
+   *     JSON value in the input string.
+   * - `"rejectDupKeys": false or true`
+   *   - If true, `parse()` returns false when a key is duplicated within an
+   *     object.
+   * - `"allowSpecialFloats": false or true`
+   *   - If true, special float values (NaNs and infinities) are allowed and
+   *     their values are lossfree restorable.
+   *
+   * You can examine 'settings_` yourself to see the defaults. You can also
+   * write and read them just like any JSON Value.
+   * \sa setDefaults()
+   */
   Json::Value settings_;
 
   CharReaderBuilder();
-  ~CharReaderBuilder() JSONCPP_OVERRIDE;
+  ~CharReaderBuilder() override;
 
-  CharReader* newCharReader() const JSONCPP_OVERRIDE;
+  CharReader* newCharReader() const override;
 
   /** \return true if 'settings' are legal and consistent;
    *   otherwise, indicate bad settings via 'invalid'.
@@ -1696,7 +1817,7 @@ public:
 
   /** A simple way to update a specific setting.
    */
-  Value& operator[](JSONCPP_STRING key);
+  Value& operator[](const String& key);
 
   /** Called by ctor, but you can use this to reset settings_.
    * \pre 'settings' != NULL (but Json::null is fine)
@@ -1713,39 +1834,37 @@ public:
 };
 
 /** Consume entire stream and use its begin/end.
-  * Someday we might have a real StreamReader, but for now this
-  * is convenient.
-  */
-bool JSON_API parseFromStream(
-    CharReader::Factory const&,
-    JSONCPP_ISTREAM&,
-    Value* root, std::string* errs);
+ * Someday we might have a real StreamReader, but for now this
+ * is convenient.
+ */
+bool JSON_API parseFromStream(CharReader::Factory const&, IStream&, Value* root,
+                              String* errs);
 
 /** \brief Read from 'sin' into 'root'.
-
- Always keep comments from the input JSON.
-
- This can be used to read a file into a particular sub-object.
- For example:
- \code
- Json::Value root;
- cin >> root["dir"]["file"];
- cout << root;
- \endcode
- Result:
- \verbatim
- {
- "dir": {
-     "file": {
-     // The input stream JSON would be nested here.
-     }
- }
- }
- \endverbatim
- \throw std::exception on parse error.
- \see Json::operator<<()
-*/
-JSON_API JSONCPP_ISTREAM& operator>>(JSONCPP_ISTREAM&, Value&);
+ *
+ * Always keep comments from the input JSON.
+ *
+ * This can be used to read a file into a particular sub-object.
+ * For example:
+ *   \code
+ *   Json::Value root;
+ *   cin >> root["dir"]["file"];
+ *   cout << root;
+ *   \endcode
+ * Result:
+ * \verbatim
+ * {
+ * "dir": {
+ *    "file": {
+ *    // The input stream JSON would be nested here.
+ *    }
+ * }
+ * }
+ * \endverbatim
+ * \throw std::exception on parse error.
+ * \see Json::operator<<()
+ */
+JSON_API IStream& operator>>(IStream&, Value&);
 
 } // namespace Json
 
@@ -1755,7 +1874,7 @@ JSON_API JSONCPP_ISTREAM& operator>>(JSONCPP_ISTREAM&, Value&);
 #pragma warning(pop)
 #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING)
 
-#endif // CPPTL_JSON_READER_H_INCLUDED
+#endif // JSON_READER_H_INCLUDED
 
 // //////////////////////////////////////////////////////////////////////
 // End of content of file: include/json/reader.h
@@ -1781,9 +1900,9 @@ JSON_API JSONCPP_ISTREAM& operator>>(JSONCPP_ISTREAM&, Value&);
 #if !defined(JSON_IS_AMALGAMATION)
 #include "value.h"
 #endif // if !defined(JSON_IS_AMALGAMATION)
-#include <vector>
-#include <string>
 #include <ostream>
+#include <string>
+#include <vector>
 
 // Disable warning C4251: <data member>: <type> needs to have dll-interface to
 // be used by...
@@ -1799,31 +1918,31 @@ namespace Json {
 class Value;
 
 /**
-
-Usage:
-\code
-  using namespace Json;
-  void writeToStdout(StreamWriter::Factory const& factory, Value const& value) {
-    std::unique_ptr<StreamWriter> const writer(
-      factory.newStreamWriter());
-    writer->write(value, &std::cout);
-    std::cout << std::endl;  // add lf and flush
-  }
-\endcode
-*/
+ *
+ * Usage:
+ *  \code
+ *  using namespace Json;
+ *  void writeToStdout(StreamWriter::Factory const& factory, Value const& value)
+ * { std::unique_ptr<StreamWriter> const writer( factory.newStreamWriter());
+ *    writer->write(value, &std::cout);
+ *    std::cout << std::endl;  // add lf and flush
+ *  }
+ *  \endcode
+ */
 class JSON_API StreamWriter {
 protected:
-  JSONCPP_OSTREAM* sout_;  // not owned; will not delete
+  OStream* sout_; // not owned; will not delete
 public:
   StreamWriter();
   virtual ~StreamWriter();
   /** Write Value into document as configured in sub-class.
-      Do not take ownership of sout, but maintain a reference during function.
-      \pre sout != NULL
-      \return zero on success (For now, we always return zero, so check the stream instead.)
-      \throw std::exception possibly, depending on configuration
+   *   Do not take ownership of sout, but maintain a reference during function.
+   *   \pre sout != NULL
+   *   \return zero on success (For now, we always return zero, so check the
+   *   stream instead.) \throw std::exception possibly, depending on
+   * configuration
    */
-  virtual int write(Value const& root, JSONCPP_OSTREAM* sout) = 0;
+  virtual int write(Value const& root, OStream* sout) = 0;
 
   /** \brief A simple abstract factory.
    */
@@ -1834,64 +1953,69 @@ public:
      * \throw std::exception if something goes wrong (e.g. invalid settings)
      */
     virtual StreamWriter* newStreamWriter() const = 0;
-  };  // Factory
-};  // StreamWriter
+  }; // Factory
+};   // StreamWriter
 
 /** \brief Write into stringstream, then return string, for convenience.
  * A StreamWriter will be created from the factory, used, and then deleted.
  */
-JSONCPP_STRING JSON_API writeString(StreamWriter::Factory const& factory, Value const& root);
-
+String JSON_API writeString(StreamWriter::Factory const& factory,
+                            Value const& root);
 
 /** \brief Build a StreamWriter implementation.
 
-Usage:
-\code
-  using namespace Json;
-  Value value = ...;
-  StreamWriterBuilder builder;
-  builder["commentStyle"] = "None";
-  builder["indentation"] = "   ";  // or whatever you like
-  std::unique_ptr<Json::StreamWriter> writer(
-      builder.newStreamWriter());
-  writer->write(value, &std::cout);
-  std::cout << std::endl;  // add lf and flush
-\endcode
+* Usage:
+*   \code
+*   using namespace Json;
+*   Value value = ...;
+*   StreamWriterBuilder builder;
+*   builder["commentStyle"] = "None";
+*   builder["indentation"] = "   ";  // or whatever you like
+*   std::unique_ptr<Json::StreamWriter> writer(
+*      builder.newStreamWriter());
+*   writer->write(value, &std::cout);
+*   std::cout << std::endl;  // add lf and flush
+*   \endcode
 */
 class JSON_API StreamWriterBuilder : public StreamWriter::Factory {
 public:
   // Note: We use a Json::Value so that we can add data-members to this class
   // without a major version bump.
   /** Configuration of this builder.
-    Available settings (case-sensitive):
-    - "commentStyle": "None" or "All"
-    - "indentation":  "<anything>"
-    - "enableYAMLCompatibility": false or true
-      - slightly change the whitespace around colons
-    - "dropNullPlaceholders": false or true
-      - Drop the "null" string from the writer's output for nullValues.
-        Strictly speaking, this is not valid JSON. But when the output is being
-        fed to a browser's JavaScript, it makes for smaller output and the
-        browser can handle the output just fine.
-    - "useSpecialFloats": false or true
-      - If true, outputs non-finite floating point values in the following way:
-        NaN values as "NaN", positive infinity as "Infinity", and negative infinity
-        as "-Infinity".
-
-    You can examine 'settings_` yourself
-    to see the defaults. You can also write and read them just like any
-    JSON Value.
-    \sa setDefaults()
-    */
+   *  Available settings (case-sensitive):
+   *  - "commentStyle": "None" or "All"
+   *  - "indentation":  "<anything>".
+   *  - Setting this to an empty string also omits newline characters.
+   *  - "enableYAMLCompatibility": false or true
+   *  - slightly change the whitespace around colons
+   *  - "dropNullPlaceholders": false or true
+   *  - Drop the "null" string from the writer's output for nullValues.
+   *    Strictly speaking, this is not valid JSON. But when the output is being
+   *    fed to a browser's JavaScript, it makes for smaller output and the
+   *    browser can handle the output just fine.
+   *  - "useSpecialFloats": false or true
+   *  - If true, outputs non-finite floating point values in the following way:
+   *    NaN values as "NaN", positive infinity as "Infinity", and negative
+   *  infinity as "-Infinity".
+   *  - "precision": int
+   *  - Number of precision digits for formatting of real values.
+   *  - "precisionType": "significant"(default) or "decimal"
+   *  - Type of precision for formatting of real values.
+
+   *  You can examine 'settings_` yourself
+   *  to see the defaults. You can also write and read them just like any
+   *  JSON Value.
+   *  \sa setDefaults()
+   */
   Json::Value settings_;
 
   StreamWriterBuilder();
-  ~StreamWriterBuilder() JSONCPP_OVERRIDE;
+  ~StreamWriterBuilder() override;
 
   /**
    * \throw std::exception if something goes wrong (e.g. invalid settings)
    */
-  StreamWriter* newStreamWriter() const JSONCPP_OVERRIDE;
+  StreamWriter* newStreamWriter() const override;
 
   /** \return true if 'settings' are legal and consistent;
    *   otherwise, indicate bad settings via 'invalid'.
@@ -1899,7 +2023,7 @@ public:
   bool validate(Json::Value* invalid) const;
   /** A simple way to update a specific setting.
    */
-  Value& operator[](JSONCPP_STRING key);
+  Value& operator[](const String& key);
 
   /** Called by ctor, but you can use this to reset settings_.
    * \pre 'settings' != NULL (but Json::null is fine)
@@ -1916,7 +2040,7 @@ class JSONCPP_DEPRECATED("Use StreamWriter instead") JSON_API Writer {
 public:
   virtual ~Writer();
 
-  virtual JSONCPP_STRING write(const Value& root) = 0;
+  virtual String write(const Value& root) = 0;
 };
 
 /** \brief Outputs a Value in <a HREF="http://www.json.org">JSON</a> format
@@ -1924,18 +2048,19 @@ public:
  *
  * The JSON document is written in a single line. It is not intended for 'human'
  *consumption,
- * but may be usefull to support feature such as RPC where bandwith is limited.
+ * but may be useful to support feature such as RPC where bandwidth is limited.
  * \sa Reader, Value
  * \deprecated Use StreamWriterBuilder.
  */
 #if defined(_MSC_VER)
 #pragma warning(push)
-#pragma warning(disable:4996) // Deriving from deprecated class
+#pragma warning(disable : 4996) // Deriving from deprecated class
 #endif
-class JSONCPP_DEPRECATED("Use StreamWriterBuilder instead") JSON_API FastWriter : public Writer {
+class JSONCPP_DEPRECATED("Use StreamWriterBuilder instead") JSON_API FastWriter
+    : public Writer {
 public:
   FastWriter();
-  ~FastWriter() JSONCPP_OVERRIDE {}
+  ~FastWriter() override = default;
 
   void enableYAMLCompatibility();
 
@@ -1949,15 +2074,15 @@ public:
   void omitEndingLineFeed();
 
 public: // overridden from Writer
-  JSONCPP_STRING write(const Value& root) JSONCPP_OVERRIDE;
+  String write(const Value& root) override;
 
 private:
   void writeValue(const Value& value);
 
-  JSONCPP_STRING document_;
-  bool yamlCompatibilityEnabled_;
-  bool dropNullPlaceholders_;
-  bool omitEndingLineFeed_;
+  String document_;
+  bool yamlCompatibilityEnabled_{false};
+  bool dropNullPlaceholders_{false};
+  bool omitEndingLineFeed_{false};
 };
 #if defined(_MSC_VER)
 #pragma warning(pop)
@@ -1989,42 +2114,43 @@ private:
  */
 #if defined(_MSC_VER)
 #pragma warning(push)
-#pragma warning(disable:4996) // Deriving from deprecated class
+#pragma warning(disable : 4996) // Deriving from deprecated class
 #endif
-class JSONCPP_DEPRECATED("Use StreamWriterBuilder instead") JSON_API StyledWriter : public Writer {
+class JSONCPP_DEPRECATED("Use StreamWriterBuilder instead") JSON_API
+    StyledWriter : public Writer {
 public:
   StyledWriter();
-  ~StyledWriter() JSONCPP_OVERRIDE {}
+  ~StyledWriter() override = default;
 
 public: // overridden from Writer
   /** \brief Serialize a Value in <a HREF="http://www.json.org">JSON</a> format.
    * \param root Value to serialize.
    * \return String containing the JSON document that represents the root value.
    */
-  JSONCPP_STRING write(const Value& root) JSONCPP_OVERRIDE;
+  String write(const Value& root) override;
 
 private:
   void writeValue(const Value& value);
   void writeArrayValue(const Value& value);
   bool isMultilineArray(const Value& value);
-  void pushValue(const JSONCPP_STRING& value);
+  void pushValue(const String& value);
   void writeIndent();
-  void writeWithIndent(const JSONCPP_STRING& value);
+  void writeWithIndent(const String& value);
   void indent();
   void unindent();
   void writeCommentBeforeValue(const Value& root);
   void writeCommentAfterValueOnSameLine(const Value& root);
-  bool hasCommentForValue(const Value& value);
-  static JSONCPP_STRING normalizeEOL(const JSONCPP_STRING& text);
+  static bool hasCommentForValue(const Value& value);
+  static String normalizeEOL(const String& text);
 
-  typedef std::vector<JSONCPP_STRING> ChildValues;
+  using ChildValues = std::vector<String>;
 
   ChildValues childValues_;
-  JSONCPP_STRING document_;
-  JSONCPP_STRING indentString_;
-  unsigned int rightMargin_;
-  unsigned int indentSize_;
-  bool addChildValues_;
+  String document_;
+  String indentString_;
+  unsigned int rightMargin_{74};
+  unsigned int indentSize_{3};
+  bool addChildValues_{false};
 };
 #if defined(_MSC_VER)
 #pragma warning(pop)
@@ -2057,15 +2183,16 @@ private:
  */
 #if defined(_MSC_VER)
 #pragma warning(push)
-#pragma warning(disable:4996) // Deriving from deprecated class
+#pragma warning(disable : 4996) // Deriving from deprecated class
 #endif
-class JSONCPP_DEPRECATED("Use StreamWriterBuilder instead") JSON_API StyledStreamWriter {
+class JSONCPP_DEPRECATED("Use StreamWriterBuilder instead") JSON_API
+    StyledStreamWriter {
 public:
-/**
- * \param indentation Each level will be indented by this amount extra.
- */
-  StyledStreamWriter(JSONCPP_STRING indentation = "\t");
-  ~StyledStreamWriter() {}
+  /**
+   * \param indentation Each level will be indented by this amount extra.
+   */
+  StyledStreamWriter(String indentation = "\t");
+  ~StyledStreamWriter() = default;
 
 public:
   /** \brief Serialize a Value in <a HREF="http://www.json.org">JSON</a> format.
@@ -2074,29 +2201,29 @@ public:
    * \note There is no point in deriving from Writer, since write() should not
    * return a value.
    */
-  void write(JSONCPP_OSTREAM& out, const Value& root);
+  void write(OStream& out, const Value& root);
 
 private:
   void writeValue(const Value& value);
   void writeArrayValue(const Value& value);
   bool isMultilineArray(const Value& value);
-  void pushValue(const JSONCPP_STRING& value);
+  void pushValue(const String& value);
   void writeIndent();
-  void writeWithIndent(const JSONCPP_STRING& value);
+  void writeWithIndent(const String& value);
   void indent();
   void unindent();
   void writeCommentBeforeValue(const Value& root);
   void writeCommentAfterValueOnSameLine(const Value& root);
-  bool hasCommentForValue(const Value& value);
-  static JSONCPP_STRING normalizeEOL(const JSONCPP_STRING& text);
+  static bool hasCommentForValue(const Value& value);
+  static String normalizeEOL(const String& text);
 
-  typedef std::vector<JSONCPP_STRING> ChildValues;
+  using ChildValues = std::vector<String>;
 
   ChildValues childValues_;
-  JSONCPP_OSTREAM* document_;
-  JSONCPP_STRING indentString_;
-  unsigned int rightMargin_;
-  JSONCPP_STRING indentation_;
+  OStream* document_;
+  String indentString_;
+  unsigned int rightMargin_{74};
+  String indentation_;
   bool addChildValues_ : 1;
   bool indented_ : 1;
 };
@@ -2105,18 +2232,20 @@ private:
 #endif
 
 #if defined(JSON_HAS_INT64)
-JSONCPP_STRING JSON_API valueToString(Int value);
-JSONCPP_STRING JSON_API valueToString(UInt value);
+String JSON_API valueToString(Int value);
+String JSON_API valueToString(UInt value);
 #endif // if defined(JSON_HAS_INT64)
-JSONCPP_STRING JSON_API valueToString(LargestInt value);
-JSONCPP_STRING JSON_API valueToString(LargestUInt value);
-JSONCPP_STRING JSON_API valueToString(double value);
-JSONCPP_STRING JSON_API valueToString(bool value);
-JSONCPP_STRING JSON_API valueToQuotedString(const char* value);
+String JSON_API valueToString(LargestInt value);
+String JSON_API valueToString(LargestUInt value);
+String JSON_API valueToString(
+    double value, unsigned int precision = Value::defaultRealPrecision,
+    PrecisionType precisionType = PrecisionType::significantDigits);
+String JSON_API valueToString(bool value);
+String JSON_API valueToQuotedString(const char* value);
 
 /// \brief Output using the StyledStreamWriter.
 /// \see Json::operator>>()
-JSON_API JSONCPP_OSTREAM& operator<<(JSONCPP_OSTREAM&, const Value& root);
+JSON_API OStream& operator<<(OStream&, const Value& root);
 
 } // namespace Json
 
@@ -2146,10 +2275,10 @@ JSON_API JSONCPP_OSTREAM& operator<<(JSONCPP_OSTREAM&, const Value& root);
 // recognized in your jurisdiction.
 // See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
 
-#ifndef CPPTL_JSON_ASSERTIONS_H_INCLUDED
-#define CPPTL_JSON_ASSERTIONS_H_INCLUDED
+#ifndef JSON_ASSERTIONS_H_INCLUDED
+#define JSON_ASSERTIONS_H_INCLUDED
 
-#include <stdlib.h>
+#include <cstdlib>
 #include <sstream>
 
 #if !defined(JSON_IS_AMALGAMATION)
@@ -2163,38 +2292,45 @@ JSON_API JSONCPP_OSTREAM& operator<<(JSONCPP_OSTREAM&, const Value& root);
 #if JSON_USE_EXCEPTION
 
 // @todo <= add detail about condition in exception
-# define JSON_ASSERT(condition)                                                \
-  {if (!(condition)) {Json::throwLogicError( "assert json failed" );}}
-
-# define JSON_FAIL_MESSAGE(message)                                            \
-  {                                                                            \
-    JSONCPP_OSTRINGSTREAM oss; oss << message;                                    \
+#define JSON_ASSERT(condition)                                                 \
+  do {                                                                         \
+    if (!(condition)) {                                                        \
+      Json::throwLogicError("assert json failed");                             \
+    }                                                                          \
+  } while (0)
+
+#define JSON_FAIL_MESSAGE(message)                                             \
+  do {                                                                         \
+    OStringStream oss;                                                         \
+    oss << message;                                                            \
     Json::throwLogicError(oss.str());                                          \
     abort();                                                                   \
-  }
+  } while (0)
 
 #else // JSON_USE_EXCEPTION
 
-# define JSON_ASSERT(condition) assert(condition)
+#define JSON_ASSERT(condition) assert(condition)
 
 // The call to assert() will show the failure message in debug builds. In
 // release builds we abort, for a core-dump or debugger.
-# define JSON_FAIL_MESSAGE(message)                                            \
+#define JSON_FAIL_MESSAGE(message)                                             \
   {                                                                            \
-    JSONCPP_OSTRINGSTREAM oss; oss << message;                                    \
+    OStringStream oss;                                                         \
+    oss << message;                                                            \
     assert(false && oss.str().c_str());                                        \
     abort();                                                                   \
   }
 
-
 #endif
 
 #define JSON_ASSERT_MESSAGE(condition, message)                                \
-  if (!(condition)) {                                                          \
-    JSON_FAIL_MESSAGE(message);                                                \
-  }
+  do {                                                                         \
+    if (!(condition)) {                                                        \
+      JSON_FAIL_MESSAGE(message);                                              \
+    }                                                                          \
+  } while (0)
 
-#endif // CPPTL_JSON_ASSERTIONS_H_INCLUDED
+#endif // JSON_ASSERTIONS_H_INCLUDED
 
 // //////////////////////////////////////////////////////////////////////
 // End of content of file: include/json/assertions.h
diff --git a/lib/jsoncpp/jsoncpp.cpp b/lib/jsoncpp/jsoncpp.cpp
index 507a1c6ad..30e0a69f7 100644
--- a/lib/jsoncpp/jsoncpp.cpp
+++ b/lib/jsoncpp/jsoncpp.cpp
@@ -92,6 +92,9 @@ license you like.
 #ifndef LIB_JSONCPP_JSON_TOOL_H_INCLUDED
 #define LIB_JSONCPP_JSON_TOOL_H_INCLUDED
 
+#if !defined(JSON_IS_AMALGAMATION)
+#include <json/config.h>
+#endif
 
 // Also support old flag NO_LOCALE_SUPPORT
 #ifdef NO_LOCALE_SUPPORT
@@ -109,7 +112,7 @@ license you like.
  */
 
 namespace Json {
-static char getDecimalPoint() {
+static inline char getDecimalPoint() {
 #ifdef JSONCPP_NO_LOCALE_SUPPORT
   return '\0';
 #else
@@ -119,8 +122,8 @@ static char getDecimalPoint() {
 }
 
 /// Converts a unicode code-point to UTF-8.
-static inline JSONCPP_STRING codePointToUTF8(unsigned int cp) {
-  JSONCPP_STRING result;
+static inline String codePointToUTF8(unsigned int cp) {
+  String result;
 
   // based on description from http://en.wikipedia.org/wiki/UTF-8
 
@@ -154,7 +157,7 @@ enum {
 };
 
 // Defines a char buffer for use with uintToString().
-typedef char UIntToStringBuffer[uintToStringBufferSize];
+using UIntToStringBuffer = char[uintToStringBufferSize];
 
 /** Converts an unsigned integer to string.
  * @param value Unsigned integer to convert to string
@@ -174,28 +177,45 @@ static inline void uintToString(LargestUInt value, char*& current) {
  * We had a sophisticated way, but it did not work in WinCE.
  * @see https://github.com/open-source-parsers/jsoncpp/pull/9
  */
-static inline void fixNumericLocale(char* begin, char* end) {
-  while (begin < end) {
+template <typename Iter> Iter fixNumericLocale(Iter begin, Iter end) {
+  for (; begin != end; ++begin) {
     if (*begin == ',') {
       *begin = '.';
     }
-    ++begin;
   }
+  return begin;
 }
 
-static inline void fixNumericLocaleInput(char* begin, char* end) {
+template <typename Iter> void fixNumericLocaleInput(Iter begin, Iter end) {
   char decimalPoint = getDecimalPoint();
-  if (decimalPoint != '\0' && decimalPoint != '.') {
-    while (begin < end) {
-      if (*begin == '.') {
-        *begin = decimalPoint;
-      }
-      ++begin;
+  if (decimalPoint == '\0' || decimalPoint == '.') {
+    return;
+  }
+  for (; begin != end; ++begin) {
+    if (*begin == '.') {
+      *begin = decimalPoint;
     }
   }
 }
 
-} // namespace Json {
+/**
+ * Return iterator that would be the new end of the range [begin,end), if we
+ * were to delete zeros in the end of string, but not the last zero before '.'.
+ */
+template <typename Iter> Iter fixZerosInTheEnd(Iter begin, Iter end) {
+  for (; begin != end; --end) {
+    if (*(end - 1) != '0') {
+      return end;
+    }
+    // Don't delete the last zero before the decimal point.
+    if (begin != (end - 1) && *(end - 2) == '.') {
+      return end;
+    }
+  }
+  return end;
+}
+
+} // namespace Json
 
 #endif // LIB_JSONCPP_JSON_TOOL_H_INCLUDED
 
@@ -219,69 +239,65 @@ static inline void fixNumericLocaleInput(char* begin, char* end) {
 // See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
 
 #if !defined(JSON_IS_AMALGAMATION)
+#include "json_tool.h"
 #include <json/assertions.h>
 #include <json/reader.h>
 #include <json/value.h>
-#include "json_tool.h"
 #endif // if !defined(JSON_IS_AMALGAMATION)
-#include <utility>
-#include <cstdio>
+#include <algorithm>
 #include <cassert>
 #include <cstring>
+#include <iostream>
 #include <istream>
-#include <sstream>
+#include <limits>
 #include <memory>
 #include <set>
-#include <limits>
+#include <sstream>
+#include <utility>
 
-#if defined(_MSC_VER)
-#if !defined(WINCE) && defined(__STDC_SECURE_LIB__) && _MSC_VER >= 1500 // VC++ 9.0 and above 
-#define snprintf sprintf_s
-#elif _MSC_VER >= 1900 // VC++ 14.0 and above
-#define snprintf std::snprintf
-#else
-#define snprintf _snprintf
-#endif
-#elif defined(__ANDROID__) || defined(__QNXNTO__)
-#define snprintf snprintf
-#elif __cplusplus >= 201103L
-#if !defined(__MINGW32__) && !defined(__CYGWIN__)
-#define snprintf std::snprintf
-#endif
-#endif
+#include <cstdio>
+#if __cplusplus >= 201103L
 
-#if defined(__QNXNTO__)
+#if !defined(sscanf)
 #define sscanf std::sscanf
 #endif
 
-#if defined(_MSC_VER) && _MSC_VER >= 1400 // VC++ 8.0
+#endif //__cplusplus
+
+#if defined(_MSC_VER)
+#if !defined(_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES)
+#define _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES 1
+#endif //_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES
+#endif //_MSC_VER
+
+#if defined(_MSC_VER)
 // Disable warning about strdup being deprecated.
 #pragma warning(disable : 4996)
 #endif
 
-// Define JSONCPP_DEPRECATED_STACK_LIMIT as an appropriate integer at compile time to change the stack limit
+// Define JSONCPP_DEPRECATED_STACK_LIMIT as an appropriate integer at compile
+// time to change the stack limit
 #if !defined(JSONCPP_DEPRECATED_STACK_LIMIT)
 #define JSONCPP_DEPRECATED_STACK_LIMIT 1000
 #endif
 
-static size_t const stackLimit_g = JSONCPP_DEPRECATED_STACK_LIMIT; // see readValue()
+static size_t const stackLimit_g =
+    JSONCPP_DEPRECATED_STACK_LIMIT; // see readValue()
 
 namespace Json {
 
 #if __cplusplus >= 201103L || (defined(_CPPLIB_VER) && _CPPLIB_VER >= 520)
-typedef std::unique_ptr<CharReader> CharReaderPtr;
+using CharReaderPtr = std::unique_ptr<CharReader>;
 #else
-typedef std::auto_ptr<CharReader>   CharReaderPtr;
+using CharReaderPtr = std::auto_ptr<CharReader>;
 #endif
 
 // Implementation of class Features
 // ////////////////////////////////
 
-Features::Features()
-    : allowComments_(true), strictRoot_(false),
-      allowDroppedNullPlaceholders_(false), allowNumericKeys_(false) {}
+Features::Features() = default;
 
-Features Features::all() { return Features(); }
+Features Features::all() { return {}; }
 
 Features Features::strictMode() {
   Features features;
@@ -296,49 +312,38 @@ Features Features::strictMode() {
 // ////////////////////////////////
 
 bool Reader::containsNewLine(Reader::Location begin, Reader::Location end) {
-  for (; begin < end; ++begin)
-    if (*begin == '\n' || *begin == '\r')
-      return true;
-  return false;
+  return std::any_of(begin, end, [](char b) { return b == '\n' || b == '\r'; });
 }
 
 // Class Reader
 // //////////////////////////////////////////////////////////////////
 
-Reader::Reader()
-    : errors_(), document_(), begin_(), end_(), current_(), lastValueEnd_(),
-      lastValue_(), commentsBefore_(), features_(Features::all()),
-      collectComments_() {}
+Reader::Reader() : features_(Features::all()) {}
 
-Reader::Reader(const Features& features)
-    : errors_(), document_(), begin_(), end_(), current_(), lastValueEnd_(),
-      lastValue_(), commentsBefore_(), features_(features), collectComments_() {
-}
+Reader::Reader(const Features& features) : features_(features) {}
 
-bool
-Reader::parse(const std::string& document, Value& root, bool collectComments) {
+bool Reader::parse(const std::string& document, Value& root,
+                   bool collectComments) {
   document_.assign(document.begin(), document.end());
   const char* begin = document_.c_str();
   const char* end = begin + document_.length();
   return parse(begin, end, root, collectComments);
 }
 
-bool Reader::parse(std::istream& sin, Value& root, bool collectComments) {
-  // std::istream_iterator<char> begin(sin);
+bool Reader::parse(std::istream& is, Value& root, bool collectComments) {
+  // std::istream_iterator<char> begin(is);
   // std::istream_iterator<char> end;
   // Those would allow streamed input from a file, if parse() were a
   // template function.
 
-  // Since JSONCPP_STRING is reference-counted, this at least does not
+  // Since String is reference-counted, this at least does not
   // create an extra copy.
-  JSONCPP_STRING doc;
-  std::getline(sin, doc, (char)EOF);
+  String doc;
+  std::getline(is, doc, static_cast<char> EOF);
   return parse(doc.data(), doc.data() + doc.size(), root, collectComments);
 }
 
-bool Reader::parse(const char* beginDoc,
-                   const char* endDoc,
-                   Value& root,
+bool Reader::parse(const char* beginDoc, const char* endDoc, Value& root,
                    bool collectComments) {
   if (!features_.allowComments_) {
     collectComments = false;
@@ -348,8 +353,8 @@ bool Reader::parse(const char* beginDoc,
   end_ = endDoc;
   collectComments_ = collectComments;
   current_ = begin_;
-  lastValueEnd_ = 0;
-  lastValue_ = 0;
+  lastValueEnd_ = nullptr;
+  lastValue_ = nullptr;
   commentsBefore_.clear();
   errors_.clear();
   while (!nodes_.empty())
@@ -379,9 +384,11 @@ bool Reader::parse(const char* beginDoc,
 
 bool Reader::readValue() {
   // readValue() may call itself only if it calls readObject() or ReadArray().
-  // These methods execute nodes_.push() just before and nodes_.pop)() just after calling readValue(). 
-  // parse() executes one nodes_.push(), so > instead of >=.
-  if (nodes_.size() > stackLimit_g) throwRuntimeError("Exceeded stackLimit in readValue().");
+  // These methods execute nodes_.push() just before and nodes_.pop)() just
+  // after calling readValue(). parse() executes one nodes_.push(), so > instead
+  // of >=.
+  if (nodes_.size() > stackLimit_g)
+    throwRuntimeError("Exceeded stackLimit in readValue().");
 
   Token token;
   skipCommentTokens(token);
@@ -407,30 +414,24 @@ bool Reader::readValue() {
   case tokenString:
     successful = decodeString(token);
     break;
-  case tokenTrue:
-    {
+  case tokenTrue: {
     Value v(true);
     currentValue().swapPayload(v);
     currentValue().setOffsetStart(token.start_ - begin_);
     currentValue().setOffsetLimit(token.end_ - begin_);
-    }
-    break;
-  case tokenFalse:
-    {
+  } break;
+  case tokenFalse: {
     Value v(false);
     currentValue().swapPayload(v);
     currentValue().setOffsetStart(token.start_ - begin_);
     currentValue().setOffsetLimit(token.end_ - begin_);
-    }
-    break;
-  case tokenNull:
-    {
+  } break;
+  case tokenNull: {
     Value v;
     currentValue().swapPayload(v);
     currentValue().setOffsetStart(token.start_ - begin_);
     currentValue().setOffsetLimit(token.end_ - begin_);
-    }
-    break;
+  } break;
   case tokenArraySeparator:
   case tokenObjectEnd:
   case tokenArrayEnd:
@@ -536,7 +537,7 @@ bool Reader::readToken(Token& token) {
   if (!ok)
     token.type_ = tokenError;
   token.end_ = current_;
-  return true;
+  return ok;
 }
 
 void Reader::skipSpaces() {
@@ -549,7 +550,7 @@ void Reader::skipSpaces() {
   }
 }
 
-bool Reader::match(Location pattern, int patternLength) {
+bool Reader::match(const Char* pattern, int patternLength) {
   if (end_ - current_ < patternLength)
     return false;
   int index = patternLength;
@@ -583,16 +584,16 @@ bool Reader::readComment() {
   return true;
 }
 
-JSONCPP_STRING Reader::normalizeEOL(Reader::Location begin, Reader::Location end) {
-  JSONCPP_STRING normalized;
+String Reader::normalizeEOL(Reader::Location begin, Reader::Location end) {
+  String normalized;
   normalized.reserve(static_cast<size_t>(end - begin));
   Reader::Location current = begin;
   while (current != end) {
     char c = *current++;
     if (c == '\r') {
       if (current != end && *current == '\n')
-         // convert dos EOL
-         ++current;
+        // convert dos EOL
+        ++current;
       // convert Mac EOL
       normalized += '\n';
     } else {
@@ -602,12 +603,12 @@ JSONCPP_STRING Reader::normalizeEOL(Reader::Location begin, Reader::Location end
   return normalized;
 }
 
-void
-Reader::addComment(Location begin, Location end, CommentPlacement placement) {
+void Reader::addComment(Location begin, Location end,
+                        CommentPlacement placement) {
   assert(collectComments_);
-  const JSONCPP_STRING& normalized = normalizeEOL(begin, end);
+  const String& normalized = normalizeEOL(begin, end);
   if (placement == commentAfterOnSameLine) {
-    assert(lastValue_ != 0);
+    assert(lastValue_ != nullptr);
     lastValue_->setComment(normalized, placement);
   } else {
     commentsBefore_ += normalized;
@@ -640,7 +641,7 @@ bool Reader::readCppStyleComment() {
 }
 
 void Reader::readNumber() {
-  const char *p = current_;
+  Location p = current_;
   char c = '0'; // stopgap for already consumed character
   // integral part
   while (c >= '0' && c <= '9')
@@ -673,12 +674,12 @@ bool Reader::readString() {
   return c == '"';
 }
 
-bool Reader::readObject(Token& tokenStart) {
+bool Reader::readObject(Token& token) {
   Token tokenName;
-  JSONCPP_STRING name;
+  String name;
   Value init(objectValue);
   currentValue().swapPayload(init);
-  currentValue().setOffsetStart(tokenStart.start_ - begin_);
+  currentValue().setOffsetStart(token.start_ - begin_);
   while (readToken(tokenName)) {
     bool initialTokenOk = true;
     while (tokenName.type_ == tokenComment && initialTokenOk)
@@ -695,15 +696,15 @@ bool Reader::readObject(Token& tokenStart) {
       Value numberName;
       if (!decodeNumber(tokenName, numberName))
         return recoverFromError(tokenObjectEnd);
-      name = JSONCPP_STRING(numberName.asCString());
+      name = numberName.asString();
     } else {
       break;
     }
 
     Token colon;
     if (!readToken(colon) || colon.type_ != tokenMemberSeparator) {
-      return addErrorAndRecover(
-          "Missing ':' after object member name", colon, tokenObjectEnd);
+      return addErrorAndRecover("Missing ':' after object member name", colon,
+                                tokenObjectEnd);
     }
     Value& value = currentValue()[name];
     nodes_.push(&value);
@@ -716,8 +717,8 @@ bool Reader::readObject(Token& tokenStart) {
     if (!readToken(comma) ||
         (comma.type_ != tokenObjectEnd && comma.type_ != tokenArraySeparator &&
          comma.type_ != tokenComment)) {
-      return addErrorAndRecover(
-          "Missing ',' or '}' in object declaration", comma, tokenObjectEnd);
+      return addErrorAndRecover("Missing ',' or '}' in object declaration",
+                                comma, tokenObjectEnd);
     }
     bool finalizeTokenOk = true;
     while (comma.type_ == tokenComment && finalizeTokenOk)
@@ -725,14 +726,14 @@ bool Reader::readObject(Token& tokenStart) {
     if (comma.type_ == tokenObjectEnd)
       return true;
   }
-  return addErrorAndRecover(
-      "Missing '}' or object member name", tokenName, tokenObjectEnd);
+  return addErrorAndRecover("Missing '}' or object member name", tokenName,
+                            tokenObjectEnd);
 }
 
-bool Reader::readArray(Token& tokenStart) {
+bool Reader::readArray(Token& token) {
   Value init(arrayValue);
   currentValue().swapPayload(init);
-  currentValue().setOffsetStart(tokenStart.start_ - begin_);
+  currentValue().setOffsetStart(token.start_ - begin_);
   skipSpaces();
   if (current_ != end_ && *current_ == ']') // empty array
   {
@@ -749,19 +750,19 @@ bool Reader::readArray(Token& tokenStart) {
     if (!ok) // error already set
       return recoverFromError(tokenArrayEnd);
 
-    Token token;
+    Token currentToken;
     // Accept Comment after last item in the array.
-    ok = readToken(token);
-    while (token.type_ == tokenComment && ok) {
-      ok = readToken(token);
+    ok = readToken(currentToken);
+    while (currentToken.type_ == tokenComment && ok) {
+      ok = readToken(currentToken);
     }
-    bool badTokenType =
-        (token.type_ != tokenArraySeparator && token.type_ != tokenArrayEnd);
+    bool badTokenType = (currentToken.type_ != tokenArraySeparator &&
+                         currentToken.type_ != tokenArrayEnd);
     if (!ok || badTokenType) {
-      return addErrorAndRecover(
-          "Missing ',' or ']' in array declaration", token, tokenArrayEnd);
+      return addErrorAndRecover("Missing ',' or ']' in array declaration",
+                                currentToken, tokenArrayEnd);
     }
-    if (token.type_ == tokenArrayEnd)
+    if (currentToken.type_ == tokenArrayEnd)
       break;
   }
   return true;
@@ -785,7 +786,8 @@ bool Reader::decodeNumber(Token& token, Value& decoded) {
   bool isNegative = *current == '-';
   if (isNegative)
     ++current;
-  // TODO: Help the compiler do the div and mod at compile time or get rid of them.
+  // TODO: Help the compiler do the div and mod at compile time or get rid of
+  // them.
   Value::LargestUInt maxIntegerValue =
       isNegative ? Value::LargestUInt(Value::maxLargestInt) + 1
                  : Value::maxLargestUInt;
@@ -795,7 +797,7 @@ bool Reader::decodeNumber(Token& token, Value& decoded) {
     Char c = *current++;
     if (c < '0' || c > '9')
       return decodeDouble(token, decoded);
-    Value::UInt digit(static_cast<Value::UInt>(c - '0'));
+    auto digit(static_cast<Value::UInt>(c - '0'));
     if (value >= threshold) {
       // We've hit or exceeded the max value divided by 10 (rounded down). If
       // a) we've only just touched the limit, b) this is the last digit, and
@@ -831,18 +833,17 @@ bool Reader::decodeDouble(Token& token) {
 
 bool Reader::decodeDouble(Token& token, Value& decoded) {
   double value = 0;
-  JSONCPP_STRING buffer(token.start_, token.end_);
-  JSONCPP_ISTRINGSTREAM is(buffer);
+  String buffer(token.start_, token.end_);
+  IStringStream is(buffer);
   if (!(is >> value))
-    return addError("'" + JSONCPP_STRING(token.start_, token.end_) +
-                        "' is not a number.",
-                    token);
+    return addError(
+        "'" + String(token.start_, token.end_) + "' is not a number.", token);
   decoded = value;
   return true;
 }
 
 bool Reader::decodeString(Token& token) {
-  JSONCPP_STRING decoded_string;
+  String decoded_string;
   if (!decodeString(token, decoded_string))
     return false;
   Value decoded(decoded_string);
@@ -852,7 +853,7 @@ bool Reader::decodeString(Token& token) {
   return true;
 }
 
-bool Reader::decodeString(Token& token, JSONCPP_STRING& decoded) {
+bool Reader::decodeString(Token& token, String& decoded) {
   decoded.reserve(static_cast<size_t>(token.end_ - token.start_ - 2));
   Location current = token.start_ + 1; // skip '"'
   Location end = token.end_ - 1;       // do not include '"'
@@ -860,7 +861,7 @@ bool Reader::decodeString(Token& token, JSONCPP_STRING& decoded) {
     Char c = *current++;
     if (c == '"')
       break;
-    else if (c == '\\') {
+    if (c == '\\') {
       if (current == end)
         return addError("Empty escape sequence in string", token, current);
       Char escape = *current++;
@@ -905,10 +906,8 @@ bool Reader::decodeString(Token& token, JSONCPP_STRING& decoded) {
   return true;
 }
 
-bool Reader::decodeUnicodeCodePoint(Token& token,
-                                    Location& current,
-                                    Location end,
-                                    unsigned int& unicode) {
+bool Reader::decodeUnicodeCodePoint(Token& token, Location& current,
+                                    Location end, unsigned int& unicode) {
 
   if (!decodeUnicodeEscapeSequence(token, current, end, unicode))
     return false;
@@ -917,10 +916,9 @@ bool Reader::decodeUnicodeCodePoint(Token& token,
     if (end - current < 6)
       return addError(
           "additional six characters expected to parse unicode surrogate pair.",
-          token,
-          current);
-    unsigned int surrogatePair;
+          token, current);
     if (*(current++) == '\\' && *(current++) == 'u') {
+      unsigned int surrogatePair;
       if (decodeUnicodeEscapeSequence(token, current, end, surrogatePair)) {
         unicode = 0x10000 + ((unicode & 0x3FF) << 10) + (surrogatePair & 0x3FF);
       } else
@@ -928,20 +926,17 @@ bool Reader::decodeUnicodeCodePoint(Token& token,
     } else
       return addError("expecting another \\u token to begin the second half of "
                       "a unicode surrogate pair",
-                      token,
-                      current);
+                      token, current);
   }
   return true;
 }
 
-bool Reader::decodeUnicodeEscapeSequence(Token& token,
-                                         Location& current,
+bool Reader::decodeUnicodeEscapeSequence(Token& token, Location& current,
                                          Location end,
                                          unsigned int& ret_unicode) {
   if (end - current < 4)
     return addError(
-        "Bad unicode escape sequence in string: four digits expected.",
-        token,
+        "Bad unicode escape sequence in string: four digits expected.", token,
         current);
   int unicode = 0;
   for (int index = 0; index < 4; ++index) {
@@ -956,15 +951,13 @@ bool Reader::decodeUnicodeEscapeSequence(Token& token,
     else
       return addError(
           "Bad unicode escape sequence in string: hexadecimal digit expected.",
-          token,
-          current);
+          token, current);
   }
   ret_unicode = static_cast<unsigned int>(unicode);
   return true;
 }
 
-bool
-Reader::addError(const JSONCPP_STRING& message, Token& token, Location extra) {
+bool Reader::addError(const String& message, Token& token, Location extra) {
   ErrorInfo info;
   info.token_ = token;
   info.message_ = message;
@@ -986,8 +979,7 @@ bool Reader::recoverFromError(TokenType skipUntilToken) {
   return false;
 }
 
-bool Reader::addErrorAndRecover(const JSONCPP_STRING& message,
-                                Token& token,
+bool Reader::addErrorAndRecover(const String& message, Token& token,
                                 TokenType skipUntilToken) {
   addError(message, token);
   return recoverFromError(skipUntilToken);
@@ -1001,8 +993,7 @@ Reader::Char Reader::getNextChar() {
   return *current_++;
 }
 
-void Reader::getLocationLineAndColumn(Location location,
-                                      int& line,
+void Reader::getLocationLineAndColumn(Location location, int& line,
                                       int& column) const {
   Location current = begin_;
   Location lastLineStart = current;
@@ -1024,25 +1015,22 @@ void Reader::getLocationLineAndColumn(Location location,
   ++line;
 }
 
-JSONCPP_STRING Reader::getLocationLineAndColumn(Location location) const {
+String Reader::getLocationLineAndColumn(Location location) const {
   int line, column;
   getLocationLineAndColumn(location, line, column);
   char buffer[18 + 16 + 16 + 1];
-  snprintf(buffer, sizeof(buffer), "Line %d, Column %d", line, column);
+  jsoncpp_snprintf(buffer, sizeof(buffer), "Line %d, Column %d", line, column);
   return buffer;
 }
 
 // Deprecated. Preserved for backward compatibility
-JSONCPP_STRING Reader::getFormatedErrorMessages() const {
+String Reader::getFormatedErrorMessages() const {
   return getFormattedErrorMessages();
 }
 
-JSONCPP_STRING Reader::getFormattedErrorMessages() const {
-  JSONCPP_STRING formattedMessage;
-  for (Errors::const_iterator itError = errors_.begin();
-       itError != errors_.end();
-       ++itError) {
-    const ErrorInfo& error = *itError;
+String Reader::getFormattedErrorMessages() const {
+  String formattedMessage;
+  for (const auto& error : errors_) {
     formattedMessage +=
         "* " + getLocationLineAndColumn(error.token_.start_) + "\n";
     formattedMessage += "  " + error.message_ + "\n";
@@ -1055,10 +1043,7 @@ JSONCPP_STRING Reader::getFormattedErrorMessages() const {
 
 std::vector<Reader::StructuredError> Reader::getStructuredErrors() const {
   std::vector<Reader::StructuredError> allErrors;
-  for (Errors::const_iterator itError = errors_.begin();
-       itError != errors_.end();
-       ++itError) {
-    const ErrorInfo& error = *itError;
+  for (const auto& error : errors_) {
     Reader::StructuredError structured;
     structured.offset_start = error.token_.start_ - begin_;
     structured.offset_limit = error.token_.end_ - begin_;
@@ -1068,28 +1053,27 @@ std::vector<Reader::StructuredError> Reader::getStructuredErrors() const {
   return allErrors;
 }
 
-bool Reader::pushError(const Value& value, const JSONCPP_STRING& message) {
+bool Reader::pushError(const Value& value, const String& message) {
   ptrdiff_t const length = end_ - begin_;
-  if(value.getOffsetStart() > length
-    || value.getOffsetLimit() > length)
+  if (value.getOffsetStart() > length || value.getOffsetLimit() > length)
     return false;
   Token token;
   token.type_ = tokenError;
   token.start_ = begin_ + value.getOffsetStart();
-  token.end_ = end_ + value.getOffsetLimit();
+  token.end_ = begin_ + value.getOffsetLimit();
   ErrorInfo info;
   info.token_ = token;
   info.message_ = message;
-  info.extra_ = 0;
+  info.extra_ = nullptr;
   errors_.push_back(info);
   return true;
 }
 
-bool Reader::pushError(const Value& value, const JSONCPP_STRING& message, const Value& extra) {
+bool Reader::pushError(const Value& value, const String& message,
+                       const Value& extra) {
   ptrdiff_t const length = end_ - begin_;
-  if(value.getOffsetStart() > length
-    || value.getOffsetLimit() > length
-    || extra.getOffsetLimit() > length)
+  if (value.getOffsetStart() > length || value.getOffsetLimit() > length ||
+      extra.getOffsetLimit() > length)
     return false;
   Token token;
   token.type_ = tokenError;
@@ -1103,15 +1087,15 @@ bool Reader::pushError(const Value& value, const JSONCPP_STRING& message, const
   return true;
 }
 
-bool Reader::good() const {
-  return !errors_.size();
-}
+bool Reader::good() const { return errors_.empty(); }
 
-// exact copy of Features
+// Originally copied from the Features class (now deprecated), used internally
+// for features implementation.
 class OurFeatures {
 public:
   static OurFeatures all();
   bool allowComments_;
+  bool allowTrailingCommas_;
   bool strictRoot_;
   bool allowDroppedNullPlaceholders_;
   bool allowNumericKeys_;
@@ -1119,42 +1103,36 @@ public:
   bool failIfExtra_;
   bool rejectDupKeys_;
   bool allowSpecialFloats_;
-  int stackLimit_;
-};  // OurFeatures
+  bool skipBom_;
+  size_t stackLimit_;
+}; // OurFeatures
 
-// exact copy of Implementation of class Features
-// ////////////////////////////////
-
-OurFeatures OurFeatures::all() { return OurFeatures(); }
+OurFeatures OurFeatures::all() { return {}; }
 
 // Implementation of class Reader
 // ////////////////////////////////
 
-// exact copy of Reader, renamed to OurReader
+// Originally copied from the Reader class (now deprecated), used internally
+// for implementing JSON reading.
 class OurReader {
 public:
-  typedef char Char;
-  typedef const Char* Location;
+  using Char = char;
+  using Location = const Char*;
   struct StructuredError {
     ptrdiff_t offset_start;
     ptrdiff_t offset_limit;
-    JSONCPP_STRING message;
+    String message;
   };
 
-  OurReader(OurFeatures const& features);
-  bool parse(const char* beginDoc,
-             const char* endDoc,
-             Value& root,
+  explicit OurReader(OurFeatures const& features);
+  bool parse(const char* beginDoc, const char* endDoc, Value& root,
              bool collectComments = true);
-  JSONCPP_STRING getFormattedErrorMessages() const;
+  String getFormattedErrorMessages() const;
   std::vector<StructuredError> getStructuredErrors() const;
-  bool pushError(const Value& value, const JSONCPP_STRING& message);
-  bool pushError(const Value& value, const JSONCPP_STRING& message, const Value& extra);
-  bool good() const;
 
 private:
-  OurReader(OurReader const&);  // no impl
-  void operator=(OurReader const&);  // no impl
+  OurReader(OurReader const&);      // no impl
+  void operator=(OurReader const&); // no impl
 
   enum TokenType {
     tokenEndOfStream = 0,
@@ -1186,17 +1164,18 @@ private:
   class ErrorInfo {
   public:
     Token token_;
-    JSONCPP_STRING message_;
+    String message_;
     Location extra_;
   };
 
-  typedef std::deque<ErrorInfo> Errors;
+  using Errors = std::deque<ErrorInfo>;
 
   bool readToken(Token& token);
   void skipSpaces();
-  bool match(Location pattern, int patternLength);
+  void skipBom(bool skipBom);
+  bool match(const Char* pattern, int patternLength);
   bool readComment();
-  bool readCStyleComment();
+  bool readCStyleComment(bool* containsNewLineResult);
   bool readCppStyleComment();
   bool readString();
   bool readStringSingleQuote();
@@ -1207,68 +1186,57 @@ private:
   bool decodeNumber(Token& token);
   bool decodeNumber(Token& token, Value& decoded);
   bool decodeString(Token& token);
-  bool decodeString(Token& token, JSONCPP_STRING& decoded);
+  bool decodeString(Token& token, String& decoded);
   bool decodeDouble(Token& token);
   bool decodeDouble(Token& token, Value& decoded);
-  bool decodeUnicodeCodePoint(Token& token,
-                              Location& current,
-                              Location end,
+  bool decodeUnicodeCodePoint(Token& token, Location& current, Location end,
                               unsigned int& unicode);
-  bool decodeUnicodeEscapeSequence(Token& token,
-                                   Location& current,
-                                   Location end,
-                                   unsigned int& unicode);
-  bool addError(const JSONCPP_STRING& message, Token& token, Location extra = 0);
+  bool decodeUnicodeEscapeSequence(Token& token, Location& current,
+                                   Location end, unsigned int& unicode);
+  bool addError(const String& message, Token& token, Location extra = nullptr);
   bool recoverFromError(TokenType skipUntilToken);
-  bool addErrorAndRecover(const JSONCPP_STRING& message,
-                          Token& token,
+  bool addErrorAndRecover(const String& message, Token& token,
                           TokenType skipUntilToken);
   void skipUntilSpace();
   Value& currentValue();
   Char getNextChar();
-  void
-  getLocationLineAndColumn(Location location, int& line, int& column) const;
-  JSONCPP_STRING getLocationLineAndColumn(Location location) const;
+  void getLocationLineAndColumn(Location location, int& line,
+                                int& column) const;
+  String getLocationLineAndColumn(Location location) const;
   void addComment(Location begin, Location end, CommentPlacement placement);
   void skipCommentTokens(Token& token);
 
-  static JSONCPP_STRING normalizeEOL(Location begin, Location end);
+  static String normalizeEOL(Location begin, Location end);
   static bool containsNewLine(Location begin, Location end);
 
-  typedef std::stack<Value*> Nodes;
-  Nodes nodes_;
-  Errors errors_;
-  JSONCPP_STRING document_;
-  Location begin_;
-  Location end_;
-  Location current_;
-  Location lastValueEnd_;
-  Value* lastValue_;
-  JSONCPP_STRING commentsBefore_;
+  using Nodes = std::stack<Value*>;
+
+  Nodes nodes_{};
+  Errors errors_{};
+  String document_{};
+  Location begin_ = nullptr;
+  Location end_ = nullptr;
+  Location current_ = nullptr;
+  Location lastValueEnd_ = nullptr;
+  Value* lastValue_ = nullptr;
+  bool lastValueHasAComment_ = false;
+  String commentsBefore_{};
 
   OurFeatures const features_;
-  bool collectComments_;
-};  // OurReader
+  bool collectComments_ = false;
+}; // OurReader
 
 // complete copy of Read impl, for OurReader
 
-bool OurReader::containsNewLine(OurReader::Location begin, OurReader::Location end) {
-  for (; begin < end; ++begin)
-    if (*begin == '\n' || *begin == '\r')
-      return true;
-  return false;
+bool OurReader::containsNewLine(OurReader::Location begin,
+                                OurReader::Location end) {
+  return std::any_of(begin, end, [](char b) { return b == '\n' || b == '\r'; });
 }
 
-OurReader::OurReader(OurFeatures const& features)
-    : errors_(), document_(), begin_(), end_(), current_(), lastValueEnd_(),
-      lastValue_(), commentsBefore_(),
-      features_(features), collectComments_() {
-}
+OurReader::OurReader(OurFeatures const& features) : features_(features) {}
 
-bool OurReader::parse(const char* beginDoc,
-                   const char* endDoc,
-                   Value& root,
-                   bool collectComments) {
+bool OurReader::parse(const char* beginDoc, const char* endDoc, Value& root,
+                      bool collectComments) {
   if (!features_.allowComments_) {
     collectComments = false;
   }
@@ -1277,22 +1245,23 @@ bool OurReader::parse(const char* beginDoc,
   end_ = endDoc;
   collectComments_ = collectComments;
   current_ = begin_;
-  lastValueEnd_ = 0;
-  lastValue_ = 0;
+  lastValueEnd_ = nullptr;
+  lastValue_ = nullptr;
   commentsBefore_.clear();
   errors_.clear();
   while (!nodes_.empty())
     nodes_.pop();
   nodes_.push(&root);
 
+  // skip byte order mark if it exists at the beginning of the UTF-8 text.
+  skipBom(features_.skipBom_);
   bool successful = readValue();
+  nodes_.pop();
   Token token;
   skipCommentTokens(token);
-  if (features_.failIfExtra_) {
-    if ((features_.strictRoot_ || token.type_ != tokenError) && token.type_ != tokenEndOfStream) {
-      addError("Extra non-whitespace after JSON value.", token);
-      return false;
-    }
+  if (features_.failIfExtra_ && (token.type_ != tokenEndOfStream)) {
+    addError("Extra non-whitespace after JSON value.", token);
+    return false;
   }
   if (collectComments_ && !commentsBefore_.empty())
     root.setComment(commentsBefore_, commentAfter);
@@ -1314,7 +1283,8 @@ bool OurReader::parse(const char* beginDoc,
 
 bool OurReader::readValue() {
   //  To preserve the old behaviour we cast size_t to int.
-  if (static_cast<int>(nodes_.size()) > features_.stackLimit_) throwRuntimeError("Exceeded stackLimit in readValue().");
+  if (nodes_.size() > features_.stackLimit_)
+    throwRuntimeError("Exceeded stackLimit in readValue().");
   Token token;
   skipCommentTokens(token);
   bool successful = true;
@@ -1339,54 +1309,42 @@ bool OurReader::readValue() {
   case tokenString:
     successful = decodeString(token);
     break;
-  case tokenTrue:
-    {
+  case tokenTrue: {
     Value v(true);
     currentValue().swapPayload(v);
     currentValue().setOffsetStart(token.start_ - begin_);
     currentValue().setOffsetLimit(token.end_ - begin_);
-    }
-    break;
-  case tokenFalse:
-    {
+  } break;
+  case tokenFalse: {
     Value v(false);
     currentValue().swapPayload(v);
     currentValue().setOffsetStart(token.start_ - begin_);
     currentValue().setOffsetLimit(token.end_ - begin_);
-    }
-    break;
-  case tokenNull:
-    {
+  } break;
+  case tokenNull: {
     Value v;
     currentValue().swapPayload(v);
     currentValue().setOffsetStart(token.start_ - begin_);
     currentValue().setOffsetLimit(token.end_ - begin_);
-    }
-    break;
-  case tokenNaN:
-    {
+  } break;
+  case tokenNaN: {
     Value v(std::numeric_limits<double>::quiet_NaN());
     currentValue().swapPayload(v);
     currentValue().setOffsetStart(token.start_ - begin_);
     currentValue().setOffsetLimit(token.end_ - begin_);
-    }
-    break;
-  case tokenPosInf:
-    {
+  } break;
+  case tokenPosInf: {
     Value v(std::numeric_limits<double>::infinity());
     currentValue().swapPayload(v);
     currentValue().setOffsetStart(token.start_ - begin_);
     currentValue().setOffsetLimit(token.end_ - begin_);
-    }
-    break;
-  case tokenNegInf:
-    {
+  } break;
+  case tokenNegInf: {
     Value v(-std::numeric_limits<double>::infinity());
     currentValue().swapPayload(v);
     currentValue().setOffsetStart(token.start_ - begin_);
     currentValue().setOffsetLimit(token.end_ - begin_);
-    }
-    break;
+  } break;
   case tokenArraySeparator:
   case tokenObjectEnd:
   case tokenArrayEnd:
@@ -1408,6 +1366,7 @@ bool OurReader::readValue() {
 
   if (collectComments_) {
     lastValueEnd_ = current_;
+    lastValueHasAComment_ = false;
     lastValue_ = &currentValue();
   }
 
@@ -1448,10 +1407,13 @@ bool OurReader::readToken(Token& token) {
     break;
   case '\'':
     if (features_.allowSingleQuotes_) {
-    token.type_ = tokenString;
-    ok = readStringSingleQuote();
+      token.type_ = tokenString;
+      ok = readStringSingleQuote();
+    } else {
+      // If we don't allow single quotes, this is a failure case.
+      ok = false;
+    }
     break;
-    } // else fall through
   case '/':
     token.type_ = tokenComment;
     ok = readComment();
@@ -1477,6 +1439,14 @@ bool OurReader::readToken(Token& token) {
       ok = features_.allowSpecialFloats_ && match("nfinity", 7);
     }
     break;
+  case '+':
+    if (readNumber(true)) {
+      token.type_ = tokenNumber;
+    } else {
+      token.type_ = tokenPosInf;
+      ok = features_.allowSpecialFloats_ && match("nfinity", 7);
+    }
+    break;
   case 't':
     token.type_ = tokenTrue;
     ok = match("rue", 3);
@@ -1521,7 +1491,7 @@ bool OurReader::readToken(Token& token) {
   if (!ok)
     token.type_ = tokenError;
   token.end_ = current_;
-  return true;
+  return ok;
 }
 
 void OurReader::skipSpaces() {
@@ -1534,7 +1504,17 @@ void OurReader::skipSpaces() {
   }
 }
 
-bool OurReader::match(Location pattern, int patternLength) {
+void OurReader::skipBom(bool skipBom) {
+  // The default behavior is to skip BOM.
+  if (skipBom) {
+    if ((end_ - begin_) >= 3 && strncmp(begin_, "\xEF\xBB\xBF", 3) == 0) {
+      begin_ += 3;
+      current_ = begin_;
+    }
+  }
+}
+
+bool OurReader::match(const Char* pattern, int patternLength) {
   if (end_ - current_ < patternLength)
     return false;
   int index = patternLength;
@@ -1546,21 +1526,32 @@ bool OurReader::match(Location pattern, int patternLength) {
 }
 
 bool OurReader::readComment() {
-  Location commentBegin = current_ - 1;
-  Char c = getNextChar();
+  const Location commentBegin = current_ - 1;
+  const Char c = getNextChar();
   bool successful = false;
-  if (c == '*')
-    successful = readCStyleComment();
-  else if (c == '/')
+  bool cStyleWithEmbeddedNewline = false;
+
+  const bool isCStyleComment = (c == '*');
+  const bool isCppStyleComment = (c == '/');
+  if (isCStyleComment) {
+    successful = readCStyleComment(&cStyleWithEmbeddedNewline);
+  } else if (isCppStyleComment) {
     successful = readCppStyleComment();
+  }
+
   if (!successful)
     return false;
 
   if (collectComments_) {
     CommentPlacement placement = commentBefore;
-    if (lastValueEnd_ && !containsNewLine(lastValueEnd_, commentBegin)) {
-      if (c != '*' || !containsNewLine(commentBegin, current_))
-        placement = commentAfterOnSameLine;
+
+    if (!lastValueHasAComment_) {
+      if (lastValueEnd_ && !containsNewLine(lastValueEnd_, commentBegin)) {
+        if (isCppStyleComment || !cStyleWithEmbeddedNewline) {
+          placement = commentAfterOnSameLine;
+          lastValueHasAComment_ = true;
+        }
+      }
     }
 
     addComment(commentBegin, current_, placement);
@@ -1568,16 +1559,17 @@ bool OurReader::readComment() {
   return true;
 }
 
-JSONCPP_STRING OurReader::normalizeEOL(OurReader::Location begin, OurReader::Location end) {
-  JSONCPP_STRING normalized;
+String OurReader::normalizeEOL(OurReader::Location begin,
+                               OurReader::Location end) {
+  String normalized;
   normalized.reserve(static_cast<size_t>(end - begin));
   OurReader::Location current = begin;
   while (current != end) {
     char c = *current++;
     if (c == '\r') {
       if (current != end && *current == '\n')
-         // convert dos EOL
-         ++current;
+        // convert dos EOL
+        ++current;
       // convert Mac EOL
       normalized += '\n';
     } else {
@@ -1587,24 +1579,29 @@ JSONCPP_STRING OurReader::normalizeEOL(OurReader::Location begin, OurReader::Loc
   return normalized;
 }
 
-void
-OurReader::addComment(Location begin, Location end, CommentPlacement placement) {
+void OurReader::addComment(Location begin, Location end,
+                           CommentPlacement placement) {
   assert(collectComments_);
-  const JSONCPP_STRING& normalized = normalizeEOL(begin, end);
+  const String& normalized = normalizeEOL(begin, end);
   if (placement == commentAfterOnSameLine) {
-    assert(lastValue_ != 0);
+    assert(lastValue_ != nullptr);
     lastValue_->setComment(normalized, placement);
   } else {
     commentsBefore_ += normalized;
   }
 }
 
-bool OurReader::readCStyleComment() {
+bool OurReader::readCStyleComment(bool* containsNewLineResult) {
+  *containsNewLineResult = false;
+
   while ((current_ + 1) < end_) {
     Char c = getNextChar();
     if (c == '*' && *current_ == '/')
       break;
+    if (c == '\n')
+      *containsNewLineResult = true;
   }
+
   return getNextChar() == '/';
 }
 
@@ -1625,7 +1622,7 @@ bool OurReader::readCppStyleComment() {
 }
 
 bool OurReader::readNumber(bool checkInf) {
-  const char *p = current_;
+  Location p = current_;
   if (checkInf && p != end_ && *p == 'I') {
     current_ = ++p;
     return false;
@@ -1662,7 +1659,6 @@ bool OurReader::readString() {
   return c == '"';
 }
 
-
 bool OurReader::readStringSingleQuote() {
   Char c = 0;
   while (current_ != end_) {
@@ -1675,19 +1671,21 @@ bool OurReader::readStringSingleQuote() {
   return c == '\'';
 }
 
-bool OurReader::readObject(Token& tokenStart) {
+bool OurReader::readObject(Token& token) {
   Token tokenName;
-  JSONCPP_STRING name;
+  String name;
   Value init(objectValue);
   currentValue().swapPayload(init);
-  currentValue().setOffsetStart(tokenStart.start_ - begin_);
+  currentValue().setOffsetStart(token.start_ - begin_);
   while (readToken(tokenName)) {
     bool initialTokenOk = true;
     while (tokenName.type_ == tokenComment && initialTokenOk)
       initialTokenOk = readToken(tokenName);
     if (!initialTokenOk)
       break;
-    if (tokenName.type_ == tokenObjectEnd && name.empty()) // empty object
+    if (tokenName.type_ == tokenObjectEnd &&
+        (name.empty() ||
+         features_.allowTrailingCommas_)) // empty object or trailing comma
       return true;
     name.clear();
     if (tokenName.type_ == tokenString) {
@@ -1701,17 +1699,17 @@ bool OurReader::readObject(Token& tokenStart) {
     } else {
       break;
     }
+    if (name.length() >= (1U << 30))
+      throwRuntimeError("keylength >= 2^30");
+    if (features_.rejectDupKeys_ && currentValue().isMember(name)) {
+      String msg = "Duplicate key: '" + name + "'";
+      return addErrorAndRecover(msg, tokenName, tokenObjectEnd);
+    }
 
     Token colon;
     if (!readToken(colon) || colon.type_ != tokenMemberSeparator) {
-      return addErrorAndRecover(
-          "Missing ':' after object member name", colon, tokenObjectEnd);
-    }
-    if (name.length() >= (1U<<30)) throwRuntimeError("keylength >= 2^30");
-    if (features_.rejectDupKeys_ && currentValue().isMember(name)) {
-      JSONCPP_STRING msg = "Duplicate key: '" + name + "'";
-      return addErrorAndRecover(
-          msg, tokenName, tokenObjectEnd);
+      return addErrorAndRecover("Missing ':' after object member name", colon,
+                                tokenObjectEnd);
     }
     Value& value = currentValue()[name];
     nodes_.push(&value);
@@ -1724,8 +1722,8 @@ bool OurReader::readObject(Token& tokenStart) {
     if (!readToken(comma) ||
         (comma.type_ != tokenObjectEnd && comma.type_ != tokenArraySeparator &&
          comma.type_ != tokenComment)) {
-      return addErrorAndRecover(
-          "Missing ',' or '}' in object declaration", comma, tokenObjectEnd);
+      return addErrorAndRecover("Missing ',' or '}' in object declaration",
+                                comma, tokenObjectEnd);
     }
     bool finalizeTokenOk = true;
     while (comma.type_ == tokenComment && finalizeTokenOk)
@@ -1733,23 +1731,27 @@ bool OurReader::readObject(Token& tokenStart) {
     if (comma.type_ == tokenObjectEnd)
       return true;
   }
-  return addErrorAndRecover(
-      "Missing '}' or object member name", tokenName, tokenObjectEnd);
+  return addErrorAndRecover("Missing '}' or object member name", tokenName,
+                            tokenObjectEnd);
 }
 
-bool OurReader::readArray(Token& tokenStart) {
+bool OurReader::readArray(Token& token) {
   Value init(arrayValue);
   currentValue().swapPayload(init);
-  currentValue().setOffsetStart(tokenStart.start_ - begin_);
-  skipSpaces();
-  if (current_ != end_ && *current_ == ']') // empty array
-  {
-    Token endArray;
-    readToken(endArray);
-    return true;
-  }
+  currentValue().setOffsetStart(token.start_ - begin_);
   int index = 0;
   for (;;) {
+    skipSpaces();
+    if (current_ != end_ && *current_ == ']' &&
+        (index == 0 ||
+         (features_.allowTrailingCommas_ &&
+          !features_.allowDroppedNullPlaceholders_))) // empty array or trailing
+                                                      // comma
+    {
+      Token endArray;
+      readToken(endArray);
+      return true;
+    }
     Value& value = currentValue()[index++];
     nodes_.push(&value);
     bool ok = readValue();
@@ -1757,19 +1759,19 @@ bool OurReader::readArray(Token& tokenStart) {
     if (!ok) // error already set
       return recoverFromError(tokenArrayEnd);
 
-    Token token;
+    Token currentToken;
     // Accept Comment after last item in the array.
-    ok = readToken(token);
-    while (token.type_ == tokenComment && ok) {
-      ok = readToken(token);
+    ok = readToken(currentToken);
+    while (currentToken.type_ == tokenComment && ok) {
+      ok = readToken(currentToken);
     }
-    bool badTokenType =
-        (token.type_ != tokenArraySeparator && token.type_ != tokenArrayEnd);
+    bool badTokenType = (currentToken.type_ != tokenArraySeparator &&
+                         currentToken.type_ != tokenArrayEnd);
     if (!ok || badTokenType) {
-      return addErrorAndRecover(
-          "Missing ',' or ']' in array declaration", token, tokenArrayEnd);
+      return addErrorAndRecover("Missing ',' or ']' in array declaration",
+                                currentToken, tokenArrayEnd);
     }
-    if (token.type_ == tokenArrayEnd)
+    if (currentToken.type_ == tokenArrayEnd)
       break;
   }
   return true;
@@ -1790,38 +1792,78 @@ bool OurReader::decodeNumber(Token& token, Value& decoded) {
   // larger than the maximum supported value of an integer then
   // we decode the number as a double.
   Location current = token.start_;
-  bool isNegative = *current == '-';
-  if (isNegative)
+  const bool isNegative = *current == '-';
+  if (isNegative) {
     ++current;
-  // TODO: Help the compiler do the div and mod at compile time or get rid of them.
-  Value::LargestUInt maxIntegerValue =
-      isNegative ? Value::LargestUInt(-Value::minLargestInt)
-                 : Value::maxLargestUInt;
-  Value::LargestUInt threshold = maxIntegerValue / 10;
+  }
+
+  // We assume we can represent the largest and smallest integer types as
+  // unsigned integers with separate sign. This is only true if they can fit
+  // into an unsigned integer.
+  static_assert(Value::maxLargestInt <= Value::maxLargestUInt,
+                "Int must be smaller than UInt");
+
+  // We need to convert minLargestInt into a positive number. The easiest way
+  // to do this conversion is to assume our "threshold" value of minLargestInt
+  // divided by 10 can fit in maxLargestInt when absolute valued. This should
+  // be a safe assumption.
+  static_assert(Value::minLargestInt <= -Value::maxLargestInt,
+                "The absolute value of minLargestInt must be greater than or "
+                "equal to maxLargestInt");
+  static_assert(Value::minLargestInt / 10 >= -Value::maxLargestInt,
+                "The absolute value of minLargestInt must be only 1 magnitude "
+                "larger than maxLargest Int");
+
+  static constexpr Value::LargestUInt positive_threshold =
+      Value::maxLargestUInt / 10;
+  static constexpr Value::UInt positive_last_digit = Value::maxLargestUInt % 10;
+
+  // For the negative values, we have to be more careful. Since typically
+  // -Value::minLargestInt will cause an overflow, we first divide by 10 and
+  // then take the inverse. This assumes that minLargestInt is only a single
+  // power of 10 different in magnitude, which we check above. For the last
+  // digit, we take the modulus before negating for the same reason.
+  static constexpr auto negative_threshold =
+      Value::LargestUInt(-(Value::minLargestInt / 10));
+  static constexpr auto negative_last_digit =
+      Value::UInt(-(Value::minLargestInt % 10));
+
+  const Value::LargestUInt threshold =
+      isNegative ? negative_threshold : positive_threshold;
+  const Value::UInt max_last_digit =
+      isNegative ? negative_last_digit : positive_last_digit;
+
   Value::LargestUInt value = 0;
   while (current < token.end_) {
     Char c = *current++;
     if (c < '0' || c > '9')
       return decodeDouble(token, decoded);
-    Value::UInt digit(static_cast<Value::UInt>(c - '0'));
+
+    const auto digit(static_cast<Value::UInt>(c - '0'));
     if (value >= threshold) {
       // We've hit or exceeded the max value divided by 10 (rounded down). If
-      // a) we've only just touched the limit, b) this is the last digit, and
+      // a) we've only just touched the limit, meaing value == threshold,
+      // b) this is the last digit, or
       // c) it's small enough to fit in that rounding delta, we're okay.
       // Otherwise treat this number as a double to avoid overflow.
       if (value > threshold || current != token.end_ ||
-          digit > maxIntegerValue % 10) {
+          digit > max_last_digit) {
         return decodeDouble(token, decoded);
       }
     }
     value = value * 10 + digit;
   }
-  if (isNegative)
-    decoded = -Value::LargestInt(value);
-  else if (value <= Value::LargestUInt(Value::maxInt))
+
+  if (isNegative) {
+    // We use the same magnitude assumption here, just in case.
+    const auto last_digit = static_cast<Value::UInt>(value % 10);
+    decoded = -Value::LargestInt(value / 10) * 10 - last_digit;
+  } else if (value <= Value::LargestUInt(Value::maxLargestInt)) {
     decoded = Value::LargestInt(value);
-  else
+  } else {
     decoded = value;
+  }
+
   return true;
 }
 
@@ -1837,44 +1879,18 @@ bool OurReader::decodeDouble(Token& token) {
 
 bool OurReader::decodeDouble(Token& token, Value& decoded) {
   double value = 0;
-  const int bufferSize = 32;
-  int count;
-  ptrdiff_t const length = token.end_ - token.start_;
-
-  // Sanity check to avoid buffer overflow exploits.
-  if (length < 0) {
-    return addError("Unable to parse token length", token);
-  }
-  size_t const ulength = static_cast<size_t>(length);
-
-  // Avoid using a string constant for the format control string given to
-  // sscanf, as this can cause hard to debug crashes on OS X. See here for more
-  // info:
-  //
-  //     http://developer.apple.com/library/mac/#DOCUMENTATION/DeveloperTools/gcc-4.0.1/gcc/Incompatibilities.html
-  char format[] = "%lf";
-
-  if (length <= bufferSize) {
-    Char buffer[bufferSize + 1];
-    memcpy(buffer, token.start_, ulength);
-    buffer[length] = 0;
-    fixNumericLocaleInput(buffer, buffer + length);
-    count = sscanf(buffer, format, &value);
-  } else {
-    JSONCPP_STRING buffer(token.start_, token.end_);
-    count = sscanf(buffer.c_str(), format, &value);
+  const String buffer(token.start_, token.end_);
+  IStringStream is(buffer);
+  if (!(is >> value)) {
+    return addError(
+        "'" + String(token.start_, token.end_) + "' is not a number.", token);
   }
-
-  if (count != 1)
-    return addError("'" + JSONCPP_STRING(token.start_, token.end_) +
-                        "' is not a number.",
-                    token);
   decoded = value;
   return true;
 }
 
 bool OurReader::decodeString(Token& token) {
-  JSONCPP_STRING decoded_string;
+  String decoded_string;
   if (!decodeString(token, decoded_string))
     return false;
   Value decoded(decoded_string);
@@ -1884,7 +1900,7 @@ bool OurReader::decodeString(Token& token) {
   return true;
 }
 
-bool OurReader::decodeString(Token& token, JSONCPP_STRING& decoded) {
+bool OurReader::decodeString(Token& token, String& decoded) {
   decoded.reserve(static_cast<size_t>(token.end_ - token.start_ - 2));
   Location current = token.start_ + 1; // skip '"'
   Location end = token.end_ - 1;       // do not include '"'
@@ -1892,7 +1908,7 @@ bool OurReader::decodeString(Token& token, JSONCPP_STRING& decoded) {
     Char c = *current++;
     if (c == '"')
       break;
-    else if (c == '\\') {
+    if (c == '\\') {
       if (current == end)
         return addError("Empty escape sequence in string", token, current);
       Char escape = *current++;
@@ -1937,10 +1953,8 @@ bool OurReader::decodeString(Token& token, JSONCPP_STRING& decoded) {
   return true;
 }
 
-bool OurReader::decodeUnicodeCodePoint(Token& token,
-                                    Location& current,
-                                    Location end,
-                                    unsigned int& unicode) {
+bool OurReader::decodeUnicodeCodePoint(Token& token, Location& current,
+                                       Location end, unsigned int& unicode) {
 
   if (!decodeUnicodeEscapeSequence(token, current, end, unicode))
     return false;
@@ -1949,10 +1963,9 @@ bool OurReader::decodeUnicodeCodePoint(Token& token,
     if (end - current < 6)
       return addError(
           "additional six characters expected to parse unicode surrogate pair.",
-          token,
-          current);
-    unsigned int surrogatePair;
+          token, current);
     if (*(current++) == '\\' && *(current++) == 'u') {
+      unsigned int surrogatePair;
       if (decodeUnicodeEscapeSequence(token, current, end, surrogatePair)) {
         unicode = 0x10000 + ((unicode & 0x3FF) << 10) + (surrogatePair & 0x3FF);
       } else
@@ -1960,20 +1973,17 @@ bool OurReader::decodeUnicodeCodePoint(Token& token,
     } else
       return addError("expecting another \\u token to begin the second half of "
                       "a unicode surrogate pair",
-                      token,
-                      current);
+                      token, current);
   }
   return true;
 }
 
-bool OurReader::decodeUnicodeEscapeSequence(Token& token,
-                                         Location& current,
-                                         Location end,
-                                         unsigned int& ret_unicode) {
+bool OurReader::decodeUnicodeEscapeSequence(Token& token, Location& current,
+                                            Location end,
+                                            unsigned int& ret_unicode) {
   if (end - current < 4)
     return addError(
-        "Bad unicode escape sequence in string: four digits expected.",
-        token,
+        "Bad unicode escape sequence in string: four digits expected.", token,
         current);
   int unicode = 0;
   for (int index = 0; index < 4; ++index) {
@@ -1988,15 +1998,13 @@ bool OurReader::decodeUnicodeEscapeSequence(Token& token,
     else
       return addError(
           "Bad unicode escape sequence in string: hexadecimal digit expected.",
-          token,
-          current);
+          token, current);
   }
   ret_unicode = static_cast<unsigned int>(unicode);
   return true;
 }
 
-bool
-OurReader::addError(const JSONCPP_STRING& message, Token& token, Location extra) {
+bool OurReader::addError(const String& message, Token& token, Location extra) {
   ErrorInfo info;
   info.token_ = token;
   info.message_ = message;
@@ -2018,9 +2026,8 @@ bool OurReader::recoverFromError(TokenType skipUntilToken) {
   return false;
 }
 
-bool OurReader::addErrorAndRecover(const JSONCPP_STRING& message,
-                                Token& token,
-                                TokenType skipUntilToken) {
+bool OurReader::addErrorAndRecover(const String& message, Token& token,
+                                   TokenType skipUntilToken) {
   addError(message, token);
   return recoverFromError(skipUntilToken);
 }
@@ -2033,9 +2040,8 @@ OurReader::Char OurReader::getNextChar() {
   return *current_++;
 }
 
-void OurReader::getLocationLineAndColumn(Location location,
-                                      int& line,
-                                      int& column) const {
+void OurReader::getLocationLineAndColumn(Location location, int& line,
+                                         int& column) const {
   Location current = begin_;
   Location lastLineStart = current;
   line = 0;
@@ -2056,20 +2062,17 @@ void OurReader::getLocationLineAndColumn(Location location,
   ++line;
 }
 
-JSONCPP_STRING OurReader::getLocationLineAndColumn(Location location) const {
+String OurReader::getLocationLineAndColumn(Location location) const {
   int line, column;
   getLocationLineAndColumn(location, line, column);
   char buffer[18 + 16 + 16 + 1];
-  snprintf(buffer, sizeof(buffer), "Line %d, Column %d", line, column);
+  jsoncpp_snprintf(buffer, sizeof(buffer), "Line %d, Column %d", line, column);
   return buffer;
 }
 
-JSONCPP_STRING OurReader::getFormattedErrorMessages() const {
-  JSONCPP_STRING formattedMessage;
-  for (Errors::const_iterator itError = errors_.begin();
-       itError != errors_.end();
-       ++itError) {
-    const ErrorInfo& error = *itError;
+String OurReader::getFormattedErrorMessages() const {
+  String formattedMessage;
+  for (const auto& error : errors_) {
     formattedMessage +=
         "* " + getLocationLineAndColumn(error.token_.start_) + "\n";
     formattedMessage += "  " + error.message_ + "\n";
@@ -2082,10 +2085,7 @@ JSONCPP_STRING OurReader::getFormattedErrorMessages() const {
 
 std::vector<OurReader::StructuredError> OurReader::getStructuredErrors() const {
   std::vector<OurReader::StructuredError> allErrors;
-  for (Errors::const_iterator itError = errors_.begin();
-       itError != errors_.end();
-       ++itError) {
-    const ErrorInfo& error = *itError;
+  for (const auto& error : errors_) {
     OurReader::StructuredError structured;
     structured.offset_start = error.token_.start_ - begin_;
     structured.offset_limit = error.token_.end_ - begin_;
@@ -2095,59 +2095,15 @@ std::vector<OurReader::StructuredError> OurReader::getStructuredErrors() const {
   return allErrors;
 }
 
-bool OurReader::pushError(const Value& value, const JSONCPP_STRING& message) {
-  ptrdiff_t length = end_ - begin_;
-  if(value.getOffsetStart() > length
-    || value.getOffsetLimit() > length)
-    return false;
-  Token token;
-  token.type_ = tokenError;
-  token.start_ = begin_ + value.getOffsetStart();
-  token.end_ = end_ + value.getOffsetLimit();
-  ErrorInfo info;
-  info.token_ = token;
-  info.message_ = message;
-  info.extra_ = 0;
-  errors_.push_back(info);
-  return true;
-}
-
-bool OurReader::pushError(const Value& value, const JSONCPP_STRING& message, const Value& extra) {
-  ptrdiff_t length = end_ - begin_;
-  if(value.getOffsetStart() > length
-    || value.getOffsetLimit() > length
-    || extra.getOffsetLimit() > length)
-    return false;
-  Token token;
-  token.type_ = tokenError;
-  token.start_ = begin_ + value.getOffsetStart();
-  token.end_ = begin_ + value.getOffsetLimit();
-  ErrorInfo info;
-  info.token_ = token;
-  info.message_ = message;
-  info.extra_ = begin_ + extra.getOffsetStart();
-  errors_.push_back(info);
-  return true;
-}
-
-bool OurReader::good() const {
-  return !errors_.size();
-}
-
-
 class OurCharReader : public CharReader {
   bool const collectComments_;
   OurReader reader_;
+
 public:
-  OurCharReader(
-    bool collectComments,
-    OurFeatures const& features)
-  : collectComments_(collectComments)
-  , reader_(features)
-  {}
-  bool parse(
-      char const* beginDoc, char const* endDoc,
-      Value* root, JSONCPP_STRING* errs) JSONCPP_OVERRIDE {
+  OurCharReader(bool collectComments, OurFeatures const& features)
+      : collectComments_(collectComments), reader_(features) {}
+  bool parse(char const* beginDoc, char const* endDoc, Value* root,
+             String* errs) override {
     bool ok = reader_.parse(beginDoc, endDoc, *root, collectComments_);
     if (errs) {
       *errs = reader_.getFormattedErrorMessages();
@@ -2156,67 +2112,64 @@ public:
   }
 };
 
-CharReaderBuilder::CharReaderBuilder()
-{
-  setDefaults(&settings_);
-}
-CharReaderBuilder::~CharReaderBuilder()
-{}
-CharReader* CharReaderBuilder::newCharReader() const
-{
+CharReaderBuilder::CharReaderBuilder() { setDefaults(&settings_); }
+CharReaderBuilder::~CharReaderBuilder() = default;
+CharReader* CharReaderBuilder::newCharReader() const {
   bool collectComments = settings_["collectComments"].asBool();
   OurFeatures features = OurFeatures::all();
   features.allowComments_ = settings_["allowComments"].asBool();
+  features.allowTrailingCommas_ = settings_["allowTrailingCommas"].asBool();
   features.strictRoot_ = settings_["strictRoot"].asBool();
-  features.allowDroppedNullPlaceholders_ = settings_["allowDroppedNullPlaceholders"].asBool();
+  features.allowDroppedNullPlaceholders_ =
+      settings_["allowDroppedNullPlaceholders"].asBool();
   features.allowNumericKeys_ = settings_["allowNumericKeys"].asBool();
   features.allowSingleQuotes_ = settings_["allowSingleQuotes"].asBool();
-  features.stackLimit_ = settings_["stackLimit"].asInt();
+
+  // Stack limit is always a size_t, so we get this as an unsigned int
+  // regardless of it we have 64-bit integer support enabled.
+  features.stackLimit_ = static_cast<size_t>(settings_["stackLimit"].asUInt());
   features.failIfExtra_ = settings_["failIfExtra"].asBool();
   features.rejectDupKeys_ = settings_["rejectDupKeys"].asBool();
   features.allowSpecialFloats_ = settings_["allowSpecialFloats"].asBool();
+  features.skipBom_ = settings_["skipBom"].asBool();
   return new OurCharReader(collectComments, features);
 }
-static void getValidReaderKeys(std::set<JSONCPP_STRING>* valid_keys)
-{
-  valid_keys->clear();
-  valid_keys->insert("collectComments");
-  valid_keys->insert("allowComments");
-  valid_keys->insert("strictRoot");
-  valid_keys->insert("allowDroppedNullPlaceholders");
-  valid_keys->insert("allowNumericKeys");
-  valid_keys->insert("allowSingleQuotes");
-  valid_keys->insert("stackLimit");
-  valid_keys->insert("failIfExtra");
-  valid_keys->insert("rejectDupKeys");
-  valid_keys->insert("allowSpecialFloats");
-}
-bool CharReaderBuilder::validate(Json::Value* invalid) const
-{
-  Json::Value my_invalid;
-  if (!invalid) invalid = &my_invalid;  // so we do not need to test for NULL
-  Json::Value& inv = *invalid;
-  std::set<JSONCPP_STRING> valid_keys;
-  getValidReaderKeys(&valid_keys);
-  Value::Members keys = settings_.getMemberNames();
-  size_t n = keys.size();
-  for (size_t i = 0; i < n; ++i) {
-    JSONCPP_STRING const& key = keys[i];
-    if (valid_keys.find(key) == valid_keys.end()) {
-      inv[key] = settings_[key];
-    }
+
+bool CharReaderBuilder::validate(Json::Value* invalid) const {
+  static const auto& valid_keys = *new std::set<String>{
+      "collectComments",
+      "allowComments",
+      "allowTrailingCommas",
+      "strictRoot",
+      "allowDroppedNullPlaceholders",
+      "allowNumericKeys",
+      "allowSingleQuotes",
+      "stackLimit",
+      "failIfExtra",
+      "rejectDupKeys",
+      "allowSpecialFloats",
+      "skipBom",
+  };
+  for (auto si = settings_.begin(); si != settings_.end(); ++si) {
+    auto key = si.name();
+    if (valid_keys.count(key))
+      continue;
+    if (invalid)
+      (*invalid)[std::move(key)] = *si;
+    else
+      return false;
   }
-  return 0u == inv.size();
+  return invalid ? invalid->empty() : true;
 }
-Value& CharReaderBuilder::operator[](JSONCPP_STRING key)
-{
+
+Value& CharReaderBuilder::operator[](const String& key) {
   return settings_[key];
 }
 // static
-void CharReaderBuilder::strictMode(Json::Value* settings)
-{
-//! [CharReaderBuilderStrictMode]
+void CharReaderBuilder::strictMode(Json::Value* settings) {
+  //! [CharReaderBuilderStrictMode]
   (*settings)["allowComments"] = false;
+  (*settings)["allowTrailingCommas"] = false;
   (*settings)["strictRoot"] = true;
   (*settings)["allowDroppedNullPlaceholders"] = false;
   (*settings)["allowNumericKeys"] = false;
@@ -2225,14 +2178,15 @@ void CharReaderBuilder::strictMode(Json::Value* settings)
   (*settings)["failIfExtra"] = true;
   (*settings)["rejectDupKeys"] = true;
   (*settings)["allowSpecialFloats"] = false;
-//! [CharReaderBuilderStrictMode]
+  (*settings)["skipBom"] = true;
+  //! [CharReaderBuilderStrictMode]
 }
 // static
-void CharReaderBuilder::setDefaults(Json::Value* settings)
-{
-//! [CharReaderBuilderDefaults]
+void CharReaderBuilder::setDefaults(Json::Value* settings) {
+  //! [CharReaderBuilderDefaults]
   (*settings)["collectComments"] = true;
   (*settings)["allowComments"] = true;
+  (*settings)["allowTrailingCommas"] = true;
   (*settings)["strictRoot"] = false;
   (*settings)["allowDroppedNullPlaceholders"] = false;
   (*settings)["allowNumericKeys"] = false;
@@ -2241,19 +2195,18 @@ void CharReaderBuilder::setDefaults(Json::Value* settings)
   (*settings)["failIfExtra"] = false;
   (*settings)["rejectDupKeys"] = false;
   (*settings)["allowSpecialFloats"] = false;
-//! [CharReaderBuilderDefaults]
+  (*settings)["skipBom"] = true;
+  //! [CharReaderBuilderDefaults]
 }
 
 //////////////////////////////////
 // global functions
 
-bool parseFromStream(
-    CharReader::Factory const& fact, JSONCPP_ISTREAM& sin,
-    Value* root, JSONCPP_STRING* errs)
-{
-  JSONCPP_OSTRINGSTREAM ssin;
+bool parseFromStream(CharReader::Factory const& fact, IStream& sin, Value* root,
+                     String* errs) {
+  OStringStream ssin;
   ssin << sin.rdbuf();
-  JSONCPP_STRING doc = ssin.str();
+  String doc = ssin.str();
   char const* begin = doc.data();
   char const* end = begin + doc.size();
   // Note that we do not actually need a null-terminator.
@@ -2261,9 +2214,9 @@ bool parseFromStream(
   return reader->parse(begin, end, root, errs);
 }
 
-JSONCPP_ISTREAM& operator>>(JSONCPP_ISTREAM& sin, Value& root) {
+IStream& operator>>(IStream& sin, Value& root) {
   CharReaderBuilder b;
-  JSONCPP_STRING errs;
+  String errs;
   bool ok = parseFromStream(b, sin, &root, &errs);
   if (!ok) {
     throwRuntimeError(errs);
@@ -2303,31 +2256,21 @@ namespace Json {
 // //////////////////////////////////////////////////////////////////
 // //////////////////////////////////////////////////////////////////
 
-ValueIteratorBase::ValueIteratorBase()
-    : current_(), isNull_(true) {
-}
+ValueIteratorBase::ValueIteratorBase() : current_() {}
 
 ValueIteratorBase::ValueIteratorBase(
     const Value::ObjectValues::iterator& current)
     : current_(current), isNull_(false) {}
 
-Value& ValueIteratorBase::deref() const {
-  return current_->second;
-}
+Value& ValueIteratorBase::deref() { return current_->second; }
+const Value& ValueIteratorBase::deref() const { return current_->second; }
 
-void ValueIteratorBase::increment() {
-  ++current_;
-}
+void ValueIteratorBase::increment() { ++current_; }
 
-void ValueIteratorBase::decrement() {
-  --current_;
-}
+void ValueIteratorBase::decrement() { --current_; }
 
 ValueIteratorBase::difference_type
 ValueIteratorBase::computeDistance(const SelfType& other) const {
-#ifdef JSON_USE_CPPTL_SMALLMAP
-  return other.current_ - current_;
-#else
   // Iterator for null value are initialized using the default
   // constructor, which initialize current_ to the default
   // std::map::iterator. As begin() and end() are two instance
@@ -2348,7 +2291,6 @@ ValueIteratorBase::computeDistance(const SelfType& other) const {
     ++myDistance;
   }
   return myDistance;
-#endif
 }
 
 bool ValueIteratorBase::isEqual(const SelfType& other) const {
@@ -2380,12 +2322,13 @@ UInt ValueIteratorBase::index() const {
   return Value::UInt(-1);
 }
 
-JSONCPP_STRING ValueIteratorBase::name() const {
+String ValueIteratorBase::name() const {
   char const* keey;
   char const* end;
   keey = memberName(&end);
-  if (!keey) return JSONCPP_STRING();
-  return JSONCPP_STRING(keey, end);
+  if (!keey)
+    return String();
+  return String(keey, end);
 }
 
 char const* ValueIteratorBase::memberName() const {
@@ -2396,8 +2339,8 @@ char const* ValueIteratorBase::memberName() const {
 char const* ValueIteratorBase::memberName(char const** end) const {
   const char* cname = (*current_).first.data();
   if (!cname) {
-    *end = NULL;
-    return NULL;
+    *end = nullptr;
+    return nullptr;
   }
   *end = cname + (*current_).first.length();
   return cname;
@@ -2411,7 +2354,7 @@ char const* ValueIteratorBase::memberName(char const** end) const {
 // //////////////////////////////////////////////////////////////////
 // //////////////////////////////////////////////////////////////////
 
-ValueConstIterator::ValueConstIterator() {}
+ValueConstIterator::ValueConstIterator() = default;
 
 ValueConstIterator::ValueConstIterator(
     const Value::ObjectValues::iterator& current)
@@ -2434,7 +2377,7 @@ operator=(const ValueIteratorBase& other) {
 // //////////////////////////////////////////////////////////////////
 // //////////////////////////////////////////////////////////////////
 
-ValueIterator::ValueIterator() {}
+ValueIterator::ValueIterator() = default;
 
 ValueIterator::ValueIterator(const Value::ObjectValues::iterator& current)
     : ValueIteratorBase(current) {}
@@ -2444,8 +2387,7 @@ ValueIterator::ValueIterator(const ValueConstIterator& other)
   throwRuntimeError("ConstIterator to Iterator should never be allowed.");
 }
 
-ValueIterator::ValueIterator(const ValueIterator& other)
-    : ValueIteratorBase(other) {}
+ValueIterator::ValueIterator(const ValueIterator& other) = default;
 
 ValueIterator& ValueIterator::operator=(const SelfType& other) {
   copy(other);
@@ -2477,20 +2419,54 @@ ValueIterator& ValueIterator::operator=(const SelfType& other) {
 #include <json/value.h>
 #include <json/writer.h>
 #endif // if !defined(JSON_IS_AMALGAMATION)
-#include <math.h>
+#include <algorithm>
+#include <cassert>
+#include <cmath>
+#include <cstddef>
+#include <cstring>
+#include <iostream>
 #include <sstream>
 #include <utility>
-#include <cstring>
-#include <cassert>
-#ifdef JSON_USE_CPPTL
-#include <cpptl/conststring.h>
+
+// Provide implementation equivalent of std::snprintf for older _MSC compilers
+#if defined(_MSC_VER) && _MSC_VER < 1900
+#include <stdarg.h>
+static int msvc_pre1900_c99_vsnprintf(char* outBuf, size_t size,
+                                      const char* format, va_list ap) {
+  int count = -1;
+  if (size != 0)
+    count = _vsnprintf_s(outBuf, size, _TRUNCATE, format, ap);
+  if (count == -1)
+    count = _vscprintf(format, ap);
+  return count;
+}
+
+int JSON_API msvc_pre1900_c99_snprintf(char* outBuf, size_t size,
+                                       const char* format, ...) {
+  va_list ap;
+  va_start(ap, format);
+  const int count = msvc_pre1900_c99_vsnprintf(outBuf, size, format, ap);
+  va_end(ap);
+  return count;
+}
+#endif
+
+// Disable warning C4702 : unreachable code
+#if defined(_MSC_VER)
+#pragma warning(disable : 4702)
 #endif
-#include <cstddef> // size_t
-#include <algorithm> // min()
 
 #define JSON_ASSERT_UNREACHABLE assert(false)
 
 namespace Json {
+template <typename T>
+static std::unique_ptr<T> cloneUnique(const std::unique_ptr<T>& p) {
+  std::unique_ptr<T> r;
+  if (p) {
+    r = std::unique_ptr<T>(new T(*p));
+  }
+  return r;
+}
 
 // This is a walkaround to avoid the static initialization of Value::null.
 // kNull must be word-aligned to avoid crashing on ARM.  We use an alignment of
@@ -2500,50 +2476,34 @@ namespace Json {
 #else
 #define ALIGNAS(byte_alignment)
 #endif
-//static const unsigned char ALIGNAS(8) kNull[sizeof(Value)] = { 0 };
-//const unsigned char& kNullRef = kNull[0];
-//const Value& Value::null = reinterpret_cast<const Value&>(kNullRef);
-//const Value& Value::nullRef = null;
 
 // static
-Value const& Value::nullSingleton()
-{
- static Value const nullStatic;
- return nullStatic;
+Value const& Value::nullSingleton() {
+  static Value const nullStatic;
+  return nullStatic;
 }
 
-// for backwards compatibility, we'll leave these global references around, but DO NOT
-// use them in JSONCPP library code any more!
+#if JSON_USE_NULLREF
+// for backwards compatibility, we'll leave these global references around, but
+// DO NOT use them in JSONCPP library code any more!
+// static
 Value const& Value::null = Value::nullSingleton();
-Value const& Value::nullRef = Value::nullSingleton();
 
-const Int Value::minInt = Int(~(UInt(-1) / 2));
-const Int Value::maxInt = Int(UInt(-1) / 2);
-const UInt Value::maxUInt = UInt(-1);
-#if defined(JSON_HAS_INT64)
-const Int64 Value::minInt64 = Int64(~(UInt64(-1) / 2));
-const Int64 Value::maxInt64 = Int64(UInt64(-1) / 2);
-const UInt64 Value::maxUInt64 = UInt64(-1);
-// The constant is hard-coded because some compiler have trouble
-// converting Value::maxUInt64 to a double correctly (AIX/xlC).
-// Assumes that UInt64 is a 64 bits integer.
-static const double maxUInt64AsDouble = 18446744073709551615.0;
-#endif // defined(JSON_HAS_INT64)
-const LargestInt Value::minLargestInt = LargestInt(~(LargestUInt(-1) / 2));
-const LargestInt Value::maxLargestInt = LargestInt(LargestUInt(-1) / 2);
-const LargestUInt Value::maxLargestUInt = LargestUInt(-1);
+// static
+Value const& Value::nullRef = Value::nullSingleton();
+#endif
 
 #if !defined(JSON_USE_INT64_DOUBLE_CONVERSION)
 template <typename T, typename U>
 static inline bool InRange(double d, T min, U max) {
   // The casts can lose precision, but we are looking only for
   // an approximate range. Might fail on edge cases though. ~cdunn
-  //return d >= static_cast<double>(min) && d <= static_cast<double>(max);
-  return d >= min && d <= max;
+  return d >= static_cast<double>(min) && d <= static_cast<double>(max);
 }
 #else  // if !defined(JSON_USE_INT64_DOUBLE_CONVERSION)
 static inline double integerToDouble(Json::UInt64 value) {
-  return static_cast<double>(Int64(value / 2)) * 2.0 + static_cast<double>(Int64(value & 1));
+  return static_cast<double>(Int64(value / 2)) * 2.0 +
+         static_cast<double>(Int64(value & 1));
 }
 
 template <typename T> static inline double integerToDouble(T value) {
@@ -2563,19 +2523,16 @@ static inline bool InRange(double d, T min, U max) {
  *               computed using strlen(value).
  * @return Pointer on the duplicate instance of string.
  */
-static inline char* duplicateStringValue(const char* value,
-                                         size_t length)
-{
+static inline char* duplicateStringValue(const char* value, size_t length) {
   // Avoid an integer overflow in the call to malloc below by limiting length
   // to a sane value.
   if (length >= static_cast<size_t>(Value::maxInt))
     length = Value::maxInt - 1;
 
-  char* newString = static_cast<char*>(malloc(length + 1));
-  if (newString == NULL) {
-    throwRuntimeError(
-        "in Json::Value::duplicateStringValue(): "
-        "Failed to allocate string value buffer");
+  auto newString = static_cast<char*>(malloc(length + 1));
+  if (newString == nullptr) {
+    throwRuntimeError("in Json::Value::duplicateStringValue(): "
+                      "Failed to allocate string value buffer");
   }
   memcpy(newString, value, length);
   newString[length] = 0;
@@ -2584,31 +2541,28 @@ static inline char* duplicateStringValue(const char* value,
 
 /* Record the length as a prefix.
  */
-static inline char* duplicateAndPrefixStringValue(
-    const char* value,
-    unsigned int length)
-{
+static inline char* duplicateAndPrefixStringValue(const char* value,
+                                                  unsigned int length) {
   // Avoid an integer overflow in the call to malloc below by limiting length
   // to a sane value.
-  JSON_ASSERT_MESSAGE(length <= static_cast<unsigned>(Value::maxInt) - sizeof(unsigned) - 1U,
+  JSON_ASSERT_MESSAGE(length <= static_cast<unsigned>(Value::maxInt) -
+                                    sizeof(unsigned) - 1U,
                       "in Json::Value::duplicateAndPrefixStringValue(): "
                       "length too big for prefixing");
-  unsigned actualLength = length + static_cast<unsigned>(sizeof(unsigned)) + 1U;
-  char* newString = static_cast<char*>(malloc(actualLength));
-  if (newString == 0) {
-    throwRuntimeError(
-        "in Json::Value::duplicateAndPrefixStringValue(): "
-        "Failed to allocate string value buffer");
+  size_t actualLength = sizeof(length) + length + 1;
+  auto newString = static_cast<char*>(malloc(actualLength));
+  if (newString == nullptr) {
+    throwRuntimeError("in Json::Value::duplicateAndPrefixStringValue(): "
+                      "Failed to allocate string value buffer");
   }
   *reinterpret_cast<unsigned*>(newString) = length;
   memcpy(newString + sizeof(unsigned), value, length);
-  newString[actualLength - 1U] = 0; // to avoid buffer over-run accidents by users later
+  newString[actualLength - 1U] =
+      0; // to avoid buffer over-run accidents by users later
   return newString;
 }
-inline static void decodePrefixedString(
-    bool isPrefixed, char const* prefixed,
-    unsigned* length, char const** value)
-{
+inline static void decodePrefixedString(bool isPrefixed, char const* prefixed,
+                                        unsigned* length, char const** value) {
   if (!isPrefixed) {
     *length = static_cast<unsigned>(strlen(prefixed));
     *value = prefixed;
@@ -2617,7 +2571,8 @@ inline static void decodePrefixedString(
     *value = prefixed + sizeof(unsigned);
   }
 }
-/** Free the string duplicated by duplicateStringValue()/duplicateAndPrefixStringValue().
+/** Free the string duplicated by
+ * duplicateStringValue()/duplicateAndPrefixStringValue().
  */
 #if JSONCPP_USING_SECURE_MEMORY
 static inline void releasePrefixedStringValue(char* value) {
@@ -2630,17 +2585,13 @@ static inline void releasePrefixedStringValue(char* value) {
 }
 static inline void releaseStringValue(char* value, unsigned length) {
   // length==0 => we allocated the strings memory
-  size_t size = (length==0) ? strlen(value) : length;
+  size_t size = (length == 0) ? strlen(value) : length;
   memset(value, 0, size);
   free(value);
 }
-#else // !JSONCPP_USING_SECURE_MEMORY
-static inline void releasePrefixedStringValue(char* value) {
-  free(value);
-}
-static inline void releaseStringValue(char* value, unsigned) {
-  free(value);
-}
+#else  // !JSONCPP_USING_SECURE_MEMORY
+static inline void releasePrefixedStringValue(char* value) { free(value); }
+static inline void releaseStringValue(char* value, unsigned) { free(value); }
 #endif // JSONCPP_USING_SECURE_MEMORY
 
 } // namespace Json
@@ -2659,58 +2610,28 @@ static inline void releaseStringValue(char* value, unsigned) {
 
 namespace Json {
 
-Exception::Exception(JSONCPP_STRING const& msg)
-  : msg_(msg)
-{}
-Exception::~Exception() JSONCPP_NOEXCEPT
-{}
-char const* Exception::what() const JSONCPP_NOEXCEPT
-{
-  return msg_.c_str();
-}
-RuntimeError::RuntimeError(JSONCPP_STRING const& msg)
-  : Exception(msg)
-{}
-LogicError::LogicError(JSONCPP_STRING const& msg)
-  : Exception(msg)
-{}
-JSONCPP_NORETURN void throwRuntimeError(JSONCPP_STRING const& msg)
-{
+#if JSON_USE_EXCEPTION
+Exception::Exception(String msg) : msg_(std::move(msg)) {}
+Exception::~Exception() noexcept = default;
+char const* Exception::what() const noexcept { return msg_.c_str(); }
+RuntimeError::RuntimeError(String const& msg) : Exception(msg) {}
+LogicError::LogicError(String const& msg) : Exception(msg) {}
+JSONCPP_NORETURN void throwRuntimeError(String const& msg) {
   throw RuntimeError(msg);
 }
-JSONCPP_NORETURN void throwLogicError(JSONCPP_STRING const& msg)
-{
+JSONCPP_NORETURN void throwLogicError(String const& msg) {
   throw LogicError(msg);
 }
-
-// //////////////////////////////////////////////////////////////////
-// //////////////////////////////////////////////////////////////////
-// //////////////////////////////////////////////////////////////////
-// class Value::CommentInfo
-// //////////////////////////////////////////////////////////////////
-// //////////////////////////////////////////////////////////////////
-// //////////////////////////////////////////////////////////////////
-
-Value::CommentInfo::CommentInfo() : comment_(0)
-{}
-
-Value::CommentInfo::~CommentInfo() {
-  if (comment_)
-    releaseStringValue(comment_, 0u);
+#else // !JSON_USE_EXCEPTION
+JSONCPP_NORETURN void throwRuntimeError(String const& msg) {
+  std::cerr << msg << std::endl;
+  abort();
 }
-
-void Value::CommentInfo::setComment(const char* text, size_t len) {
-  if (comment_) {
-    releaseStringValue(comment_, 0u);
-    comment_ = 0;
-  }
-  JSON_ASSERT(text != 0);
-  JSON_ASSERT_MESSAGE(
-      text[0] == '\0' || text[0] == '/',
-      "in Json::Value::setComment(): Comments must start with /");
-  // It seems that /**/ style comments are acceptable as well.
-  comment_ = duplicateStringValue(text, len);
+JSONCPP_NORETURN void throwLogicError(String const& msg) {
+  std::cerr << msg << std::endl;
+  abort();
 }
+#endif
 
 // //////////////////////////////////////////////////////////////////
 // //////////////////////////////////////////////////////////////////
@@ -2723,36 +2644,44 @@ void Value::CommentInfo::setComment(const char* text, size_t len) {
 // Notes: policy_ indicates if the string was allocated when
 // a string is stored.
 
-Value::CZString::CZString(ArrayIndex aindex) : cstr_(0), index_(aindex) {}
+Value::CZString::CZString(ArrayIndex index) : cstr_(nullptr), index_(index) {}
 
-Value::CZString::CZString(char const* str, unsigned ulength, DuplicationPolicy allocate)
+Value::CZString::CZString(char const* str, unsigned length,
+                          DuplicationPolicy allocate)
     : cstr_(str) {
   // allocate != duplicate
   storage_.policy_ = allocate & 0x3;
-  storage_.length_ = ulength & 0x3FFFFFFF;
+  storage_.length_ = length & 0x3FFFFFFF;
 }
 
 Value::CZString::CZString(const CZString& other) {
-  cstr_ = (other.storage_.policy_ != noDuplication && other.cstr_ != 0
-				 ? duplicateStringValue(other.cstr_, other.storage_.length_)
-				 : other.cstr_);
-  storage_.policy_ = static_cast<unsigned>(other.cstr_
-                 ? (static_cast<DuplicationPolicy>(other.storage_.policy_) == noDuplication
-                     ? noDuplication : duplicate)
-                 : static_cast<DuplicationPolicy>(other.storage_.policy_)) & 3U;
+  cstr_ = (other.storage_.policy_ != noDuplication && other.cstr_ != nullptr
+               ? duplicateStringValue(other.cstr_, other.storage_.length_)
+               : other.cstr_);
+  storage_.policy_ =
+      static_cast<unsigned>(
+          other.cstr_
+              ? (static_cast<DuplicationPolicy>(other.storage_.policy_) ==
+                         noDuplication
+                     ? noDuplication
+                     : duplicate)
+              : static_cast<DuplicationPolicy>(other.storage_.policy_)) &
+      3U;
   storage_.length_ = other.storage_.length_;
 }
 
-#if JSON_HAS_RVALUE_REFERENCES
 Value::CZString::CZString(CZString&& other)
-  : cstr_(other.cstr_), index_(other.index_) {
+    : cstr_(other.cstr_), index_(other.index_) {
   other.cstr_ = nullptr;
 }
-#endif
 
 Value::CZString::~CZString() {
   if (cstr_ && storage_.policy_ == duplicate) {
-	  releaseStringValue(const_cast<char*>(cstr_), storage_.length_ + 1u); //+1 for null terminating character for sake of completeness but not actually necessary
+    releaseStringValue(const_cast<char*>(cstr_),
+                       storage_.length_ + 1U); // +1 for null terminating
+                                               // character for sake of
+                                               // completeness but not actually
+                                               // necessary
   }
 }
 
@@ -2767,36 +2696,39 @@ Value::CZString& Value::CZString::operator=(const CZString& other) {
   return *this;
 }
 
-#if JSON_HAS_RVALUE_REFERENCES
 Value::CZString& Value::CZString::operator=(CZString&& other) {
   cstr_ = other.cstr_;
   index_ = other.index_;
   other.cstr_ = nullptr;
   return *this;
 }
-#endif
 
 bool Value::CZString::operator<(const CZString& other) const {
-  if (!cstr_) return index_ < other.index_;
-  //return strcmp(cstr_, other.cstr_) < 0;
+  if (!cstr_)
+    return index_ < other.index_;
+  // return strcmp(cstr_, other.cstr_) < 0;
   // Assume both are strings.
   unsigned this_len = this->storage_.length_;
   unsigned other_len = other.storage_.length_;
   unsigned min_len = std::min<unsigned>(this_len, other_len);
   JSON_ASSERT(this->cstr_ && other.cstr_);
   int comp = memcmp(this->cstr_, other.cstr_, min_len);
-  if (comp < 0) return true;
-  if (comp > 0) return false;
+  if (comp < 0)
+    return true;
+  if (comp > 0)
+    return false;
   return (this_len < other_len);
 }
 
 bool Value::CZString::operator==(const CZString& other) const {
-  if (!cstr_) return index_ == other.index_;
-  //return strcmp(cstr_, other.cstr_) == 0;
+  if (!cstr_)
+    return index_ == other.index_;
+  // return strcmp(cstr_, other.cstr_) == 0;
   // Assume both are strings.
   unsigned this_len = this->storage_.length_;
   unsigned other_len = other.storage_.length_;
-  if (this_len != other_len) return false;
+  if (this_len != other_len)
+    return false;
   JSON_ASSERT(this->cstr_ && other.cstr_);
   int comp = memcmp(this->cstr_, other.cstr_, this_len);
   return comp == 0;
@@ -2804,10 +2736,12 @@ bool Value::CZString::operator==(const CZString& other) const {
 
 ArrayIndex Value::CZString::index() const { return index_; }
 
-//const char* Value::CZString::c_str() const { return cstr_; }
+// const char* Value::CZString::c_str() const { return cstr_; }
 const char* Value::CZString::data() const { return cstr_; }
 unsigned Value::CZString::length() const { return storage_.length_; }
-bool Value::CZString::isStaticString() const { return storage_.policy_ == noDuplication; }
+bool Value::CZString::isStaticString() const {
+  return storage_.policy_ == noDuplication;
+}
 
 // //////////////////////////////////////////////////////////////////
 // //////////////////////////////////////////////////////////////////
@@ -2821,10 +2755,10 @@ bool Value::CZString::isStaticString() const { return storage_.policy_ == noDupl
  * memset( this, 0, sizeof(Value) )
  * This optimization is used in ValueInternalMap fast allocator.
  */
-Value::Value(ValueType vtype) {
+Value::Value(ValueType type) {
   static char const emptyString[] = "";
-  initBasic(vtype);
-  switch (vtype) {
+  initBasic(type);
+  switch (type) {
   case nullValue:
     break;
   case intValue:
@@ -2877,20 +2811,22 @@ Value::Value(double value) {
 
 Value::Value(const char* value) {
   initBasic(stringValue, true);
-  JSON_ASSERT_MESSAGE(value != NULL, "Null Value Passed to Value Constructor");
-  value_.string_ = duplicateAndPrefixStringValue(value, static_cast<unsigned>(strlen(value)));
+  JSON_ASSERT_MESSAGE(value != nullptr,
+                      "Null Value Passed to Value Constructor");
+  value_.string_ = duplicateAndPrefixStringValue(
+      value, static_cast<unsigned>(strlen(value)));
 }
 
-Value::Value(const char* beginValue, const char* endValue) {
+Value::Value(const char* begin, const char* end) {
   initBasic(stringValue, true);
   value_.string_ =
-      duplicateAndPrefixStringValue(beginValue, static_cast<unsigned>(endValue - beginValue));
+      duplicateAndPrefixStringValue(begin, static_cast<unsigned>(end - begin));
 }
 
-Value::Value(const JSONCPP_STRING& value) {
+Value::Value(const String& value) {
   initBasic(stringValue, true);
-  value_.string_ =
-      duplicateAndPrefixStringValue(value.data(), static_cast<unsigned>(value.length()));
+  value_.string_ = duplicateAndPrefixStringValue(
+      value.data(), static_cast<unsigned>(value.length()));
 }
 
 Value::Value(const StaticString& value) {
@@ -2898,114 +2834,44 @@ Value::Value(const StaticString& value) {
   value_.string_ = const_cast<char*>(value.c_str());
 }
 
-#ifdef JSON_USE_CPPTL
-Value::Value(const CppTL::ConstString& value) {
-  initBasic(stringValue, true);
-  value_.string_ = duplicateAndPrefixStringValue(value, static_cast<unsigned>(value.length()));
-}
-#endif
-
 Value::Value(bool value) {
   initBasic(booleanValue);
   value_.bool_ = value;
 }
 
-Value::Value(Value const& other)
-    : type_(other.type_), allocated_(false)
-      ,
-      comments_(0), start_(other.start_), limit_(other.limit_)
-{
-  switch (type_) {
-  case nullValue:
-  case intValue:
-  case uintValue:
-  case realValue:
-  case booleanValue:
-    value_ = other.value_;
-    break;
-  case stringValue:
-    if (other.value_.string_ && other.allocated_) {
-      unsigned len;
-      char const* str;
-      decodePrefixedString(other.allocated_, other.value_.string_,
-          &len, &str);
-      value_.string_ = duplicateAndPrefixStringValue(str, len);
-      allocated_ = true;
-    } else {
-      value_.string_ = other.value_.string_;
-      allocated_ = false;
-    }
-    break;
-  case arrayValue:
-  case objectValue:
-    value_.map_ = new ObjectValues(*other.value_.map_);
-    break;
-  default:
-    JSON_ASSERT_UNREACHABLE;
-  }
-  if (other.comments_) {
-    comments_ = new CommentInfo[numberOfCommentPlacement];
-    for (int comment = 0; comment < numberOfCommentPlacement; ++comment) {
-      const CommentInfo& otherComment = other.comments_[comment];
-      if (otherComment.comment_)
-        comments_[comment].setComment(
-            otherComment.comment_, strlen(otherComment.comment_));
-    }
-  }
+Value::Value(const Value& other) {
+  dupPayload(other);
+  dupMeta(other);
 }
 
-#if JSON_HAS_RVALUE_REFERENCES
-// Move constructor
 Value::Value(Value&& other) {
   initBasic(nullValue);
   swap(other);
 }
-#endif
 
 Value::~Value() {
-  switch (type_) {
-  case nullValue:
-  case intValue:
-  case uintValue:
-  case realValue:
-  case booleanValue:
-    break;
-  case stringValue:
-    if (allocated_)
-      releasePrefixedStringValue(value_.string_);
-    break;
-  case arrayValue:
-  case objectValue:
-    delete value_.map_;
-    break;
-  default:
-    JSON_ASSERT_UNREACHABLE;
-  }
-
-  delete[] comments_;
-
+  releasePayload();
   value_.uint_ = 0;
 }
 
-Value& Value::operator=(Value other) {
-  swap(other);
+Value& Value::operator=(const Value& other) {
+  Value(other).swap(*this);
+  return *this;
+}
+
+Value& Value::operator=(Value&& other) {
+  other.swap(*this);
   return *this;
 }
 
 void Value::swapPayload(Value& other) {
-  ValueType temp = type_;
-  type_ = other.type_;
-  other.type_ = temp;
+  std::swap(bits_, other.bits_);
   std::swap(value_, other.value_);
-  int temp2 = allocated_;
-  allocated_ = other.allocated_;
-  other.allocated_ = temp2 & 0x1;
 }
 
 void Value::copyPayload(const Value& other) {
-  type_ = other.type_;
-  value_ = other.value_;
-  allocated_ = other.allocated_;
+  releasePayload();
+  dupPayload(other);
 }
 
 void Value::swap(Value& other) {
@@ -3017,12 +2883,12 @@ void Value::swap(Value& other) {
 
 void Value::copy(const Value& other) {
   copyPayload(other);
-  comments_ = other.comments_;
-  start_ = other.start_;
-  limit_ = other.limit_;
+  dupMeta(other);
 }
 
-ValueType Value::type() const { return type_; }
+ValueType Value::type() const {
+  return static_cast<ValueType>(bits_.value_type_);
+}
 
 int Value::compare(const Value& other) const {
   if (*this < other)
@@ -3033,10 +2899,10 @@ int Value::compare(const Value& other) const {
 }
 
 bool Value::operator<(const Value& other) const {
-  int typeDelta = type_ - other.type_;
+  int typeDelta = type() - other.type();
   if (typeDelta)
-    return typeDelta < 0 ? true : false;
-  switch (type_) {
+    return typeDelta < 0;
+  switch (type()) {
   case nullValue:
     return false;
   case intValue:
@@ -3047,30 +2913,33 @@ bool Value::operator<(const Value& other) const {
     return value_.real_ < other.value_.real_;
   case booleanValue:
     return value_.bool_ < other.value_.bool_;
-  case stringValue:
-  {
-    if ((value_.string_ == 0) || (other.value_.string_ == 0)) {
-      if (other.value_.string_) return true;
-      else return false;
+  case stringValue: {
+    if ((value_.string_ == nullptr) || (other.value_.string_ == nullptr)) {
+      return other.value_.string_ != nullptr;
     }
     unsigned this_len;
     unsigned other_len;
     char const* this_str;
     char const* other_str;
-    decodePrefixedString(this->allocated_, this->value_.string_, &this_len, &this_str);
-    decodePrefixedString(other.allocated_, other.value_.string_, &other_len, &other_str);
+    decodePrefixedString(this->isAllocated(), this->value_.string_, &this_len,
+                         &this_str);
+    decodePrefixedString(other.isAllocated(), other.value_.string_, &other_len,
+                         &other_str);
     unsigned min_len = std::min<unsigned>(this_len, other_len);
     JSON_ASSERT(this_str && other_str);
     int comp = memcmp(this_str, other_str, min_len);
-    if (comp < 0) return true;
-    if (comp > 0) return false;
+    if (comp < 0)
+      return true;
+    if (comp > 0)
+      return false;
     return (this_len < other_len);
   }
   case arrayValue:
   case objectValue: {
-    int delta = int(value_.map_->size() - other.value_.map_->size());
-    if (delta)
-      return delta < 0;
+    auto thisSize = value_.map_->size();
+    auto otherSize = other.value_.map_->size();
+    if (thisSize != otherSize)
+      return thisSize < otherSize;
     return (*value_.map_) < (*other.value_.map_);
   }
   default:
@@ -3086,14 +2955,9 @@ bool Value::operator>=(const Value& other) const { return !(*this < other); }
 bool Value::operator>(const Value& other) const { return other < *this; }
 
 bool Value::operator==(const Value& other) const {
-  // if ( type_ != other.type_ )
-  // GCC 2.95.3 says:
-  // attempt to take address of bit-field structure member `Json::Value::type_'
-  // Beats me, but a temp solves the problem.
-  int temp = other.type_;
-  if (type_ != temp)
+  if (type() != other.type())
     return false;
-  switch (type_) {
+  switch (type()) {
   case nullValue:
     return true;
   case intValue:
@@ -3104,18 +2968,20 @@ bool Value::operator==(const Value& other) const {
     return value_.real_ == other.value_.real_;
   case booleanValue:
     return value_.bool_ == other.value_.bool_;
-  case stringValue:
-  {
-    if ((value_.string_ == 0) || (other.value_.string_ == 0)) {
+  case stringValue: {
+    if ((value_.string_ == nullptr) || (other.value_.string_ == nullptr)) {
       return (value_.string_ == other.value_.string_);
     }
     unsigned this_len;
     unsigned other_len;
     char const* this_str;
     char const* other_str;
-    decodePrefixedString(this->allocated_, this->value_.string_, &this_len, &this_str);
-    decodePrefixedString(other.allocated_, other.value_.string_, &other_len, &other_str);
-    if (this_len != other_len) return false;
+    decodePrefixedString(this->isAllocated(), this->value_.string_, &this_len,
+                         &this_str);
+    decodePrefixedString(other.isAllocated(), other.value_.string_, &other_len,
+                         &other_str);
+    if (this_len != other_len)
+      return false;
     JSON_ASSERT(this_str && other_str);
     int comp = memcmp(this_str, other_str, this_len);
     return comp == 0;
@@ -3133,47 +2999,55 @@ bool Value::operator==(const Value& other) const {
 bool Value::operator!=(const Value& other) const { return !(*this == other); }
 
 const char* Value::asCString() const {
-  JSON_ASSERT_MESSAGE(type_ == stringValue,
+  JSON_ASSERT_MESSAGE(type() == stringValue,
                       "in Json::Value::asCString(): requires stringValue");
-  if (value_.string_ == 0) return 0;
+  if (value_.string_ == nullptr)
+    return nullptr;
   unsigned this_len;
   char const* this_str;
-  decodePrefixedString(this->allocated_, this->value_.string_, &this_len, &this_str);
+  decodePrefixedString(this->isAllocated(), this->value_.string_, &this_len,
+                       &this_str);
   return this_str;
 }
 
 #if JSONCPP_USING_SECURE_MEMORY
 unsigned Value::getCStringLength() const {
-  JSON_ASSERT_MESSAGE(type_ == stringValue,
-	                  "in Json::Value::asCString(): requires stringValue");
-  if (value_.string_ == 0) return 0;
+  JSON_ASSERT_MESSAGE(type() == stringValue,
+                      "in Json::Value::asCString(): requires stringValue");
+  if (value_.string_ == 0)
+    return 0;
   unsigned this_len;
   char const* this_str;
-  decodePrefixedString(this->allocated_, this->value_.string_, &this_len, &this_str);
+  decodePrefixedString(this->isAllocated(), this->value_.string_, &this_len,
+                       &this_str);
   return this_len;
 }
 #endif
 
-bool Value::getString(char const** str, char const** cend) const {
-  if (type_ != stringValue) return false;
-  if (value_.string_ == 0) return false;
+bool Value::getString(char const** begin, char const** end) const {
+  if (type() != stringValue)
+    return false;
+  if (value_.string_ == nullptr)
+    return false;
   unsigned length;
-  decodePrefixedString(this->allocated_, this->value_.string_, &length, str);
-  *cend = *str + length;
+  decodePrefixedString(this->isAllocated(), this->value_.string_, &length,
+                       begin);
+  *end = *begin + length;
   return true;
 }
 
-JSONCPP_STRING Value::asString() const {
-  switch (type_) {
+String Value::asString() const {
+  switch (type()) {
   case nullValue:
     return "";
-  case stringValue:
-  {
-    if (value_.string_ == 0) return "";
+  case stringValue: {
+    if (value_.string_ == nullptr)
+      return "";
     unsigned this_len;
     char const* this_str;
-    decodePrefixedString(this->allocated_, this->value_.string_, &this_len, &this_str);
-    return JSONCPP_STRING(this_str, this_len);
+    decodePrefixedString(this->isAllocated(), this->value_.string_, &this_len,
+                         &this_str);
+    return String(this_str, this_len);
   }
   case booleanValue:
     return value_.bool_ ? "true" : "false";
@@ -3188,18 +3062,8 @@ JSONCPP_STRING Value::asString() const {
   }
 }
 
-#ifdef JSON_USE_CPPTL
-CppTL::ConstString Value::asConstString() const {
-  unsigned len;
-  char const* str;
-  decodePrefixedString(allocated_, value_.string_,
-      &len, &str);
-  return CppTL::ConstString(str, len);
-}
-#endif
-
 Value::Int Value::asInt() const {
-  switch (type_) {
+  switch (type()) {
   case intValue:
     JSON_ASSERT_MESSAGE(isInt(), "LargestInt out of Int range");
     return Int(value_.int_);
@@ -3221,7 +3085,7 @@ Value::Int Value::asInt() const {
 }
 
 Value::UInt Value::asUInt() const {
-  switch (type_) {
+  switch (type()) {
   case intValue:
     JSON_ASSERT_MESSAGE(isUInt(), "LargestInt out of UInt range");
     return UInt(value_.int_);
@@ -3245,7 +3109,7 @@ Value::UInt Value::asUInt() const {
 #if defined(JSON_HAS_INT64)
 
 Value::Int64 Value::asInt64() const {
-  switch (type_) {
+  switch (type()) {
   case intValue:
     return Int64(value_.int_);
   case uintValue:
@@ -3266,7 +3130,7 @@ Value::Int64 Value::asInt64() const {
 }
 
 Value::UInt64 Value::asUInt64() const {
-  switch (type_) {
+  switch (type()) {
   case intValue:
     JSON_ASSERT_MESSAGE(isUInt64(), "LargestInt out of UInt64 range");
     return UInt64(value_.int_);
@@ -3304,7 +3168,7 @@ LargestUInt Value::asLargestUInt() const {
 }
 
 double Value::asDouble() const {
-  switch (type_) {
+  switch (type()) {
   case intValue:
     return static_cast<double>(value_.int_);
   case uintValue:
@@ -3326,7 +3190,7 @@ double Value::asDouble() const {
 }
 
 float Value::asFloat() const {
-  switch (type_) {
+  switch (type()) {
   case intValue:
     return static_cast<float>(value_.int_);
   case uintValue:
@@ -3341,7 +3205,7 @@ float Value::asFloat() const {
   case nullValue:
     return 0.0;
   case booleanValue:
-    return value_.bool_ ? 1.0f : 0.0f;
+    return value_.bool_ ? 1.0F : 0.0F;
   default:
     break;
   }
@@ -3349,18 +3213,20 @@ float Value::asFloat() const {
 }
 
 bool Value::asBool() const {
-  switch (type_) {
+  switch (type()) {
   case booleanValue:
     return value_.bool_;
   case nullValue:
     return false;
   case intValue:
-    return value_.int_ ? true : false;
+    return value_.int_ != 0;
   case uintValue:
-    return value_.uint_ ? true : false;
-  case realValue:
-    // This is kind of strange. Not recommended.
-    return (value_.real_ != 0.0) ? true : false;
+    return value_.uint_ != 0;
+  case realValue: {
+    // According to JavaScript language zero or NaN is regarded as false
+    const auto value_classification = std::fpclassify(value_.real_);
+    return value_classification != FP_ZERO && value_classification != FP_NAN;
+  }
   default:
     break;
   }
@@ -3371,30 +3237,30 @@ bool Value::isConvertibleTo(ValueType other) const {
   switch (other) {
   case nullValue:
     return (isNumeric() && asDouble() == 0.0) ||
-           (type_ == booleanValue && value_.bool_ == false) ||
-           (type_ == stringValue && asString().empty()) ||
-           (type_ == arrayValue && value_.map_->size() == 0) ||
-           (type_ == objectValue && value_.map_->size() == 0) ||
-           type_ == nullValue;
+           (type() == booleanValue && !value_.bool_) ||
+           (type() == stringValue && asString().empty()) ||
+           (type() == arrayValue && value_.map_->empty()) ||
+           (type() == objectValue && value_.map_->empty()) ||
+           type() == nullValue;
   case intValue:
     return isInt() ||
-           (type_ == realValue && InRange(value_.real_, minInt, maxInt)) ||
-           type_ == booleanValue || type_ == nullValue;
+           (type() == realValue && InRange(value_.real_, minInt, maxInt)) ||
+           type() == booleanValue || type() == nullValue;
   case uintValue:
     return isUInt() ||
-           (type_ == realValue && InRange(value_.real_, 0, maxUInt)) ||
-           type_ == booleanValue || type_ == nullValue;
+           (type() == realValue && InRange(value_.real_, 0, maxUInt)) ||
+           type() == booleanValue || type() == nullValue;
   case realValue:
-    return isNumeric() || type_ == booleanValue || type_ == nullValue;
+    return isNumeric() || type() == booleanValue || type() == nullValue;
   case booleanValue:
-    return isNumeric() || type_ == booleanValue || type_ == nullValue;
+    return isNumeric() || type() == booleanValue || type() == nullValue;
   case stringValue:
-    return isNumeric() || type_ == booleanValue || type_ == stringValue ||
-           type_ == nullValue;
+    return isNumeric() || type() == booleanValue || type() == stringValue ||
+           type() == nullValue;
   case arrayValue:
-    return type_ == arrayValue || type_ == nullValue;
+    return type() == arrayValue || type() == nullValue;
   case objectValue:
-    return type_ == objectValue || type_ == nullValue;
+    return type() == objectValue || type() == nullValue;
   }
   JSON_ASSERT_UNREACHABLE;
   return false;
@@ -3402,7 +3268,7 @@ bool Value::isConvertibleTo(ValueType other) const {
 
 /// Number of values in array or object
 ArrayIndex Value::size() const {
-  switch (type_) {
+  switch (type()) {
   case nullValue:
   case intValue:
   case uintValue:
@@ -3426,20 +3292,19 @@ ArrayIndex Value::size() const {
 
 bool Value::empty() const {
   if (isNull() || isArray() || isObject())
-    return size() == 0u;
-  else
-    return false;
+    return size() == 0U;
+  return false;
 }
 
-Value::operator bool() const { return ! isNull(); }
+Value::operator bool() const { return !isNull(); }
 
 void Value::clear() {
-  JSON_ASSERT_MESSAGE(type_ == nullValue || type_ == arrayValue ||
-                          type_ == objectValue,
+  JSON_ASSERT_MESSAGE(type() == nullValue || type() == arrayValue ||
+                          type() == objectValue,
                       "in Json::Value::clear(): requires complex value");
   start_ = 0;
   limit_ = 0;
-  switch (type_) {
+  switch (type()) {
   case arrayValue:
   case objectValue:
     value_.map_->clear();
@@ -3450,15 +3315,15 @@ void Value::clear() {
 }
 
 void Value::resize(ArrayIndex newSize) {
-  JSON_ASSERT_MESSAGE(type_ == nullValue || type_ == arrayValue,
+  JSON_ASSERT_MESSAGE(type() == nullValue || type() == arrayValue,
                       "in Json::Value::resize(): requires arrayValue");
-  if (type_ == nullValue)
+  if (type() == nullValue)
     *this = Value(arrayValue);
   ArrayIndex oldSize = size();
   if (newSize == 0)
     clear();
   else if (newSize > oldSize)
-    (*this)[newSize - 1];
+    this->operator[](newSize - 1);
   else {
     for (ArrayIndex index = newSize; index < oldSize; ++index) {
       value_.map_->erase(index);
@@ -3469,12 +3334,12 @@ void Value::resize(ArrayIndex newSize) {
 
 Value& Value::operator[](ArrayIndex index) {
   JSON_ASSERT_MESSAGE(
-      type_ == nullValue || type_ == arrayValue,
+      type() == nullValue || type() == arrayValue,
       "in Json::Value::operator[](ArrayIndex): requires arrayValue");
-  if (type_ == nullValue)
+  if (type() == nullValue)
     *this = Value(arrayValue);
   CZString key(index);
-  ObjectValues::iterator it = value_.map_->lower_bound(key);
+  auto it = value_.map_->lower_bound(key);
   if (it != value_.map_->end() && (*it).first == key)
     return (*it).second;
 
@@ -3492,9 +3357,9 @@ Value& Value::operator[](int index) {
 
 const Value& Value::operator[](ArrayIndex index) const {
   JSON_ASSERT_MESSAGE(
-      type_ == nullValue || type_ == arrayValue,
+      type() == nullValue || type() == arrayValue,
       "in Json::Value::operator[](ArrayIndex)const: requires arrayValue");
-  if (type_ == nullValue)
+  if (type() == nullValue)
     return nullSingleton();
   CZString key(index);
   ObjectValues::const_iterator it = value_.map_->find(key);
@@ -3510,26 +3375,85 @@ const Value& Value::operator[](int index) const {
   return (*this)[ArrayIndex(index)];
 }
 
-void Value::initBasic(ValueType vtype, bool allocated) {
-  type_ = vtype;
-  allocated_ = allocated;
-  comments_ = 0;
+void Value::initBasic(ValueType type, bool allocated) {
+  setType(type);
+  setIsAllocated(allocated);
+  comments_ = Comments{};
   start_ = 0;
   limit_ = 0;
 }
 
+void Value::dupPayload(const Value& other) {
+  setType(other.type());
+  setIsAllocated(false);
+  switch (type()) {
+  case nullValue:
+  case intValue:
+  case uintValue:
+  case realValue:
+  case booleanValue:
+    value_ = other.value_;
+    break;
+  case stringValue:
+    if (other.value_.string_ && other.isAllocated()) {
+      unsigned len;
+      char const* str;
+      decodePrefixedString(other.isAllocated(), other.value_.string_, &len,
+                           &str);
+      value_.string_ = duplicateAndPrefixStringValue(str, len);
+      setIsAllocated(true);
+    } else {
+      value_.string_ = other.value_.string_;
+    }
+    break;
+  case arrayValue:
+  case objectValue:
+    value_.map_ = new ObjectValues(*other.value_.map_);
+    break;
+  default:
+    JSON_ASSERT_UNREACHABLE;
+  }
+}
+
+void Value::releasePayload() {
+  switch (type()) {
+  case nullValue:
+  case intValue:
+  case uintValue:
+  case realValue:
+  case booleanValue:
+    break;
+  case stringValue:
+    if (isAllocated())
+      releasePrefixedStringValue(value_.string_);
+    break;
+  case arrayValue:
+  case objectValue:
+    delete value_.map_;
+    break;
+  default:
+    JSON_ASSERT_UNREACHABLE;
+  }
+}
+
+void Value::dupMeta(const Value& other) {
+  comments_ = other.comments_;
+  start_ = other.start_;
+  limit_ = other.limit_;
+}
+
 // Access an object value by name, create a null member if it does not exist.
 // @pre Type of '*this' is object or null.
 // @param key is null-terminated.
 Value& Value::resolveReference(const char* key) {
   JSON_ASSERT_MESSAGE(
-      type_ == nullValue || type_ == objectValue,
+      type() == nullValue || type() == objectValue,
       "in Json::Value::resolveReference(): requires objectValue");
-  if (type_ == nullValue)
+  if (type() == nullValue)
     *this = Value(objectValue);
-  CZString actualKey(
-      key, static_cast<unsigned>(strlen(key)), CZString::noDuplication); // NOTE!
-  ObjectValues::iterator it = value_.map_->lower_bound(actualKey);
+  CZString actualKey(key, static_cast<unsigned>(strlen(key)),
+                     CZString::noDuplication); // NOTE!
+  auto it = value_.map_->lower_bound(actualKey);
   if (it != value_.map_->end() && (*it).first == actualKey)
     return (*it).second;
 
@@ -3540,16 +3464,15 @@ Value& Value::resolveReference(const char* key) {
 }
 
 // @param key is not null-terminated.
-Value& Value::resolveReference(char const* key, char const* cend)
-{
+Value& Value::resolveReference(char const* key, char const* end) {
   JSON_ASSERT_MESSAGE(
-      type_ == nullValue || type_ == objectValue,
+      type() == nullValue || type() == objectValue,
       "in Json::Value::resolveReference(key, end): requires objectValue");
-  if (type_ == nullValue)
+  if (type() == nullValue)
     *this = Value(objectValue);
-  CZString actualKey(
-      key, static_cast<unsigned>(cend-key), CZString::duplicateOnCopy);
-  ObjectValues::iterator it = value_.map_->lower_bound(actualKey);
+  CZString actualKey(key, static_cast<unsigned>(end - key),
+                     CZString::duplicateOnCopy);
+  auto it = value_.map_->lower_bound(actualKey);
   if (it != value_.map_->end() && (*it).first == actualKey)
     return (*it).second;
 
@@ -3566,27 +3489,35 @@ Value Value::get(ArrayIndex index, const Value& defaultValue) const {
 
 bool Value::isValidIndex(ArrayIndex index) const { return index < size(); }
 
-Value const* Value::find(char const* key, char const* cend) const
-{
-  JSON_ASSERT_MESSAGE(
-      type_ == nullValue || type_ == objectValue,
-      "in Json::Value::find(key, end, found): requires objectValue or nullValue");
-  if (type_ == nullValue) return NULL;
-  CZString actualKey(key, static_cast<unsigned>(cend-key), CZString::noDuplication);
+Value const* Value::find(char const* begin, char const* end) const {
+  JSON_ASSERT_MESSAGE(type() == nullValue || type() == objectValue,
+                      "in Json::Value::find(begin, end): requires "
+                      "objectValue or nullValue");
+  if (type() == nullValue)
+    return nullptr;
+  CZString actualKey(begin, static_cast<unsigned>(end - begin),
+                     CZString::noDuplication);
   ObjectValues::const_iterator it = value_.map_->find(actualKey);
-  if (it == value_.map_->end()) return NULL;
+  if (it == value_.map_->end())
+    return nullptr;
   return &(*it).second;
 }
-const Value& Value::operator[](const char* key) const
-{
+Value* Value::demand(char const* begin, char const* end) {
+  JSON_ASSERT_MESSAGE(type() == nullValue || type() == objectValue,
+                      "in Json::Value::demand(begin, end): requires "
+                      "objectValue or nullValue");
+  return &resolveReference(begin, end);
+}
+const Value& Value::operator[](const char* key) const {
   Value const* found = find(key, key + strlen(key));
-  if (!found) return nullSingleton();
+  if (!found)
+    return nullSingleton();
   return *found;
 }
-Value const& Value::operator[](JSONCPP_STRING const& key) const
-{
+Value const& Value::operator[](const String& key) const {
   Value const* found = find(key.data(), key.data() + key.length());
-  if (!found) return nullSingleton();
+  if (!found)
+    return nullSingleton();
   return *found;
 }
 
@@ -3594,7 +3525,7 @@ Value& Value::operator[](const char* key) {
   return resolveReference(key, key + strlen(key));
 }
 
-Value& Value::operator[](const JSONCPP_STRING& key) {
+Value& Value::operator[](const String& key) {
   return resolveReference(key.data(), key.data() + key.length());
 }
 
@@ -3602,178 +3533,140 @@ Value& Value::operator[](const StaticString& key) {
   return resolveReference(key.c_str());
 }
 
-#ifdef JSON_USE_CPPTL
-Value& Value::operator[](const CppTL::ConstString& key) {
-  return resolveReference(key.c_str(), key.end_c_str());
-}
-Value const& Value::operator[](CppTL::ConstString const& key) const
-{
-  Value const* found = find(key.c_str(), key.end_c_str());
-  if (!found) return nullSingleton();
-  return *found;
+Value& Value::append(const Value& value) { return append(Value(value)); }
+
+Value& Value::append(Value&& value) {
+  JSON_ASSERT_MESSAGE(type() == nullValue || type() == arrayValue,
+                      "in Json::Value::append: requires arrayValue");
+  if (type() == nullValue) {
+    *this = Value(arrayValue);
+  }
+  return this->value_.map_->emplace(size(), std::move(value)).first->second;
 }
-#endif
 
-Value& Value::append(const Value& value) { return (*this)[size()] = value; }
+bool Value::insert(ArrayIndex index, const Value& newValue) {
+  return insert(index, Value(newValue));
+}
 
-#if JSON_HAS_RVALUE_REFERENCES
-  Value& Value::append(Value&& value) { return (*this)[size()] = std::move(value); }
-#endif
+bool Value::insert(ArrayIndex index, Value&& newValue) {
+  JSON_ASSERT_MESSAGE(type() == nullValue || type() == arrayValue,
+                      "in Json::Value::insert: requires arrayValue");
+  ArrayIndex length = size();
+  if (index > length) {
+    return false;
+  }
+  for (ArrayIndex i = length; i > index; i--) {
+    (*this)[i] = std::move((*this)[i - 1]);
+  }
+  (*this)[index] = std::move(newValue);
+  return true;
+}
 
-Value Value::get(char const* key, char const* cend, Value const& defaultValue) const
-{
-  Value const* found = find(key, cend);
+Value Value::get(char const* begin, char const* end,
+                 Value const& defaultValue) const {
+  Value const* found = find(begin, end);
   return !found ? defaultValue : *found;
 }
-Value Value::get(char const* key, Value const& defaultValue) const
-{
+Value Value::get(char const* key, Value const& defaultValue) const {
   return get(key, key + strlen(key), defaultValue);
 }
-Value Value::get(JSONCPP_STRING const& key, Value const& defaultValue) const
-{
+Value Value::get(String const& key, Value const& defaultValue) const {
   return get(key.data(), key.data() + key.length(), defaultValue);
 }
 
-
-bool Value::removeMember(const char* key, const char* cend, Value* removed)
-{
-  if (type_ != objectValue) {
+bool Value::removeMember(const char* begin, const char* end, Value* removed) {
+  if (type() != objectValue) {
     return false;
   }
-  CZString actualKey(key, static_cast<unsigned>(cend-key), CZString::noDuplication);
-  ObjectValues::iterator it = value_.map_->find(actualKey);
+  CZString actualKey(begin, static_cast<unsigned>(end - begin),
+                     CZString::noDuplication);
+  auto it = value_.map_->find(actualKey);
   if (it == value_.map_->end())
     return false;
-  *removed = it->second;
+  if (removed)
+    *removed = std::move(it->second);
   value_.map_->erase(it);
   return true;
 }
-bool Value::removeMember(const char* key, Value* removed)
-{
+bool Value::removeMember(const char* key, Value* removed) {
   return removeMember(key, key + strlen(key), removed);
 }
-bool Value::removeMember(JSONCPP_STRING const& key, Value* removed)
-{
+bool Value::removeMember(String const& key, Value* removed) {
   return removeMember(key.data(), key.data() + key.length(), removed);
 }
-void Value::removeMember(const char* key)
-{
-  JSON_ASSERT_MESSAGE(type_ == nullValue || type_ == objectValue,
+void Value::removeMember(const char* key) {
+  JSON_ASSERT_MESSAGE(type() == nullValue || type() == objectValue,
                       "in Json::Value::removeMember(): requires objectValue");
-  if (type_ == nullValue)
+  if (type() == nullValue)
     return;
 
   CZString actualKey(key, unsigned(strlen(key)), CZString::noDuplication);
   value_.map_->erase(actualKey);
 }
-void Value::removeMember(const JSONCPP_STRING& key)
-{
-  removeMember(key.c_str());
-}
+void Value::removeMember(const String& key) { removeMember(key.c_str()); }
 
 bool Value::removeIndex(ArrayIndex index, Value* removed) {
-  if (type_ != arrayValue) {
+  if (type() != arrayValue) {
     return false;
   }
   CZString key(index);
-  ObjectValues::iterator it = value_.map_->find(key);
+  auto it = value_.map_->find(key);
   if (it == value_.map_->end()) {
     return false;
   }
-  *removed = it->second;
+  if (removed)
+    *removed = it->second;
   ArrayIndex oldSize = size();
   // shift left all items left, into the place of the "removed"
-  for (ArrayIndex i = index; i < (oldSize - 1); ++i){
+  for (ArrayIndex i = index; i < (oldSize - 1); ++i) {
     CZString keey(i);
     (*value_.map_)[keey] = (*this)[i + 1];
   }
   // erase the last one ("leftover")
   CZString keyLast(oldSize - 1);
-  ObjectValues::iterator itLast = value_.map_->find(keyLast);
+  auto itLast = value_.map_->find(keyLast);
   value_.map_->erase(itLast);
   return true;
 }
 
-#ifdef JSON_USE_CPPTL
-Value Value::get(const CppTL::ConstString& key,
-                 const Value& defaultValue) const {
-  return get(key.c_str(), key.end_c_str(), defaultValue);
+bool Value::isMember(char const* begin, char const* end) const {
+  Value const* value = find(begin, end);
+  return nullptr != value;
 }
-#endif
-
-bool Value::isMember(char const* key, char const* cend) const
-{
-  Value const* value = find(key, cend);
-  return NULL != value;
-}
-bool Value::isMember(char const* key) const
-{
+bool Value::isMember(char const* key) const {
   return isMember(key, key + strlen(key));
 }
-bool Value::isMember(JSONCPP_STRING const& key) const
-{
+bool Value::isMember(String const& key) const {
   return isMember(key.data(), key.data() + key.length());
 }
 
-#ifdef JSON_USE_CPPTL
-bool Value::isMember(const CppTL::ConstString& key) const {
-  return isMember(key.c_str(), key.end_c_str());
-}
-#endif
-
 Value::Members Value::getMemberNames() const {
   JSON_ASSERT_MESSAGE(
-      type_ == nullValue || type_ == objectValue,
+      type() == nullValue || type() == objectValue,
       "in Json::Value::getMemberNames(), value must be objectValue");
-  if (type_ == nullValue)
+  if (type() == nullValue)
     return Value::Members();
   Members members;
   members.reserve(value_.map_->size());
   ObjectValues::const_iterator it = value_.map_->begin();
   ObjectValues::const_iterator itEnd = value_.map_->end();
   for (; it != itEnd; ++it) {
-    members.push_back(JSONCPP_STRING((*it).first.data(),
-                                  (*it).first.length()));
+    members.push_back(String((*it).first.data(), (*it).first.length()));
   }
   return members;
 }
-//
-//# ifdef JSON_USE_CPPTL
-// EnumMemberNames
-// Value::enumMemberNames() const
-//{
-//   if ( type_ == objectValue )
-//   {
-//      return CppTL::Enum::any(  CppTL::Enum::transform(
-//         CppTL::Enum::keys( *(value_.map_), CppTL::Type<const CZString &>() ),
-//         MemberNamesTransform() ) );
-//   }
-//   return EnumMemberNames();
-//}
-//
-//
-// EnumValues
-// Value::enumValues() const
-//{
-//   if ( type_ == objectValue  ||  type_ == arrayValue )
-//      return CppTL::Enum::anyValues( *(value_.map_),
-//                                     CppTL::Type<const Value &>() );
-//   return EnumValues();
-//}
-//
-//# endif
 
 static bool IsIntegral(double d) {
   double integral_part;
   return modf(d, &integral_part) == 0.0;
 }
 
-bool Value::isNull() const { return type_ == nullValue; }
+bool Value::isNull() const { return type() == nullValue; }
 
-bool Value::isBool() const { return type_ == booleanValue; }
+bool Value::isBool() const { return type() == booleanValue; }
 
 bool Value::isInt() const {
-  switch (type_) {
+  switch (type()) {
   case intValue:
 #if defined(JSON_HAS_INT64)
     return value_.int_ >= minInt && value_.int_ <= maxInt;
@@ -3792,7 +3685,7 @@ bool Value::isInt() const {
 }
 
 bool Value::isUInt() const {
-  switch (type_) {
+  switch (type()) {
   case intValue:
 #if defined(JSON_HAS_INT64)
     return value_.int_ >= 0 && LargestUInt(value_.int_) <= LargestUInt(maxUInt);
@@ -3816,7 +3709,7 @@ bool Value::isUInt() const {
 
 bool Value::isInt64() const {
 #if defined(JSON_HAS_INT64)
-  switch (type_) {
+  switch (type()) {
   case intValue:
     return true;
   case uintValue:
@@ -3836,7 +3729,7 @@ bool Value::isInt64() const {
 
 bool Value::isUInt64() const {
 #if defined(JSON_HAS_INT64)
-  switch (type_) {
+  switch (type()) {
   case intValue:
     return value_.int_ >= 0;
   case uintValue:
@@ -3855,61 +3748,92 @@ bool Value::isUInt64() const {
 }
 
 bool Value::isIntegral() const {
-  switch (type_) {
-    case intValue:
-    case uintValue:
-      return true;
-    case realValue:
+  switch (type()) {
+  case intValue:
+  case uintValue:
+    return true;
+  case realValue:
 #if defined(JSON_HAS_INT64)
-      // Note that maxUInt64 (= 2^64 - 1) is not exactly representable as a
-      // double, so double(maxUInt64) will be rounded up to 2^64. Therefore we
-      // require the value to be strictly less than the limit.
-      return value_.real_ >= double(minInt64) && value_.real_ < maxUInt64AsDouble && IsIntegral(value_.real_);
+    // Note that maxUInt64 (= 2^64 - 1) is not exactly representable as a
+    // double, so double(maxUInt64) will be rounded up to 2^64. Therefore we
+    // require the value to be strictly less than the limit.
+    return value_.real_ >= double(minInt64) &&
+           value_.real_ < maxUInt64AsDouble && IsIntegral(value_.real_);
 #else
-      return value_.real_ >= minInt && value_.real_ <= maxUInt && IsIntegral(value_.real_);
+    return value_.real_ >= minInt && value_.real_ <= maxUInt &&
+           IsIntegral(value_.real_);
 #endif // JSON_HAS_INT64
-    default:
-      break;
+  default:
+    break;
   }
   return false;
 }
 
-bool Value::isDouble() const { return type_ == intValue || type_ == uintValue || type_ == realValue; }
+bool Value::isDouble() const {
+  return type() == intValue || type() == uintValue || type() == realValue;
+}
 
 bool Value::isNumeric() const { return isDouble(); }
 
-bool Value::isString() const { return type_ == stringValue; }
+bool Value::isString() const { return type() == stringValue; }
 
-bool Value::isArray() const { return type_ == arrayValue; }
+bool Value::isArray() const { return type() == arrayValue; }
 
-bool Value::isObject() const { return type_ == objectValue; }
+bool Value::isObject() const { return type() == objectValue; }
 
-void Value::setComment(const char* comment, size_t len, CommentPlacement placement) {
-  if (!comments_)
-    comments_ = new CommentInfo[numberOfCommentPlacement];
-  if ((len > 0) && (comment[len-1] == '\n')) {
-    // Always discard trailing newline, to aid indentation.
-    len -= 1;
-  }
-  comments_[placement].setComment(comment, len);
+Value::Comments::Comments(const Comments& that)
+    : ptr_{cloneUnique(that.ptr_)} {}
+
+Value::Comments::Comments(Comments&& that) : ptr_{std::move(that.ptr_)} {}
+
+Value::Comments& Value::Comments::operator=(const Comments& that) {
+  ptr_ = cloneUnique(that.ptr_);
+  return *this;
+}
+
+Value::Comments& Value::Comments::operator=(Comments&& that) {
+  ptr_ = std::move(that.ptr_);
+  return *this;
+}
+
+bool Value::Comments::has(CommentPlacement slot) const {
+  return ptr_ && !(*ptr_)[slot].empty();
 }
 
-void Value::setComment(const char* comment, CommentPlacement placement) {
-  setComment(comment, strlen(comment), placement);
+String Value::Comments::get(CommentPlacement slot) const {
+  if (!ptr_)
+    return {};
+  return (*ptr_)[slot];
 }
 
-void Value::setComment(const JSONCPP_STRING& comment, CommentPlacement placement) {
-  setComment(comment.c_str(), comment.length(), placement);
+void Value::Comments::set(CommentPlacement slot, String comment) {
+  if (!ptr_) {
+    ptr_ = std::unique_ptr<Array>(new Array());
+  }
+  // check comments array boundry.
+  if (slot < CommentPlacement::numberOfCommentPlacement) {
+    (*ptr_)[slot] = std::move(comment);
+  }
+}
+
+void Value::setComment(String comment, CommentPlacement placement) {
+  if (!comment.empty() && (comment.back() == '\n')) {
+    // Always discard trailing newline, to aid indentation.
+    comment.pop_back();
+  }
+  JSON_ASSERT(!comment.empty());
+  JSON_ASSERT_MESSAGE(
+      comment[0] == '\0' || comment[0] == '/',
+      "in Json::Value::setComment(): Comments must start with /");
+  comments_.set(placement, std::move(comment));
 }
 
 bool Value::hasComment(CommentPlacement placement) const {
-  return comments_ != 0 && comments_[placement].comment_ != 0;
+  return comments_.has(placement);
 }
 
-JSONCPP_STRING Value::getComment(CommentPlacement placement) const {
-  if (hasComment(placement))
-    return comments_[placement].comment_;
-  return "";
+String Value::getComment(CommentPlacement placement) const {
+  return comments_.get(placement);
 }
 
 void Value::setOffsetStart(ptrdiff_t start) { start_ = start; }
@@ -3920,18 +3844,18 @@ ptrdiff_t Value::getOffsetStart() const { return start_; }
 
 ptrdiff_t Value::getOffsetLimit() const { return limit_; }
 
-JSONCPP_STRING Value::toStyledString() const {
+String Value::toStyledString() const {
   StreamWriterBuilder builder;
 
-  JSONCPP_STRING out = this->hasComment(commentBefore) ? "\n" : "";
+  String out = this->hasComment(commentBefore) ? "\n" : "";
   out += Json::writeString(builder, *this);
-  out += "\n";
+  out += '\n';
 
   return out;
 }
 
 Value::const_iterator Value::begin() const {
-  switch (type_) {
+  switch (type()) {
   case arrayValue:
   case objectValue:
     if (value_.map_)
@@ -3940,11 +3864,11 @@ Value::const_iterator Value::begin() const {
   default:
     break;
   }
-  return const_iterator();
+  return {};
 }
 
 Value::const_iterator Value::end() const {
-  switch (type_) {
+  switch (type()) {
   case arrayValue:
   case objectValue:
     if (value_.map_)
@@ -3953,11 +3877,11 @@ Value::const_iterator Value::end() const {
   default:
     break;
   }
-  return const_iterator();
+  return {};
 }
 
 Value::iterator Value::begin() {
-  switch (type_) {
+  switch (type()) {
   case arrayValue:
   case objectValue:
     if (value_.map_)
@@ -3970,7 +3894,7 @@ Value::iterator Value::begin() {
 }
 
 Value::iterator Value::end() {
-  switch (type_) {
+  switch (type()) {
   case arrayValue:
   case objectValue:
     if (value_.map_)
@@ -3985,25 +3909,20 @@ Value::iterator Value::end() {
 // class PathArgument
 // //////////////////////////////////////////////////////////////////
 
-PathArgument::PathArgument() : key_(), index_(), kind_(kindNone) {}
+PathArgument::PathArgument() = default;
 
 PathArgument::PathArgument(ArrayIndex index)
-    : key_(), index_(index), kind_(kindIndex) {}
+    : index_(index), kind_(kindIndex) {}
 
-PathArgument::PathArgument(const char* key)
-    : key_(key), index_(), kind_(kindKey) {}
+PathArgument::PathArgument(const char* key) : key_(key), kind_(kindKey) {}
 
-PathArgument::PathArgument(const JSONCPP_STRING& key)
-    : key_(key.c_str()), index_(), kind_(kindKey) {}
+PathArgument::PathArgument(String key) : key_(std::move(key)), kind_(kindKey) {}
 
 // class Path
 // //////////////////////////////////////////////////////////////////
 
-Path::Path(const JSONCPP_STRING& path,
-           const PathArgument& a1,
-           const PathArgument& a2,
-           const PathArgument& a3,
-           const PathArgument& a4,
+Path::Path(const String& path, const PathArgument& a1, const PathArgument& a2,
+           const PathArgument& a3, const PathArgument& a4,
            const PathArgument& a5) {
   InArgs in;
   in.reserve(5);
@@ -4015,10 +3934,10 @@ Path::Path(const JSONCPP_STRING& path,
   makePath(path, in);
 }
 
-void Path::makePath(const JSONCPP_STRING& path, const InArgs& in) {
+void Path::makePath(const String& path, const InArgs& in) {
   const char* current = path.c_str();
   const char* end = current + path.length();
-  InArgs::const_iterator itInArg = in.begin();
+  auto itInArg = in.begin();
   while (current != end) {
     if (*current == '[') {
       ++current;
@@ -4041,13 +3960,12 @@ void Path::makePath(const JSONCPP_STRING& path, const InArgs& in) {
       const char* beginName = current;
       while (current != end && !strchr("[.", *current))
         ++current;
-      args_.push_back(JSONCPP_STRING(beginName, current));
+      args_.push_back(String(beginName, current));
     }
   }
 }
 
-void Path::addPathInArg(const JSONCPP_STRING& /*path*/,
-                        const InArgs& in,
+void Path::addPathInArg(const String& /*path*/, const InArgs& in,
                         InArgs::const_iterator& itInArg,
                         PathArgument::Kind kind) {
   if (itInArg == in.end()) {
@@ -4059,30 +3977,29 @@ void Path::addPathInArg(const JSONCPP_STRING& /*path*/,
   }
 }
 
-void Path::invalidPath(const JSONCPP_STRING& /*path*/, int /*location*/) {
+void Path::invalidPath(const String& /*path*/, int /*location*/) {
   // Error: invalid path.
 }
 
 const Value& Path::resolve(const Value& root) const {
   const Value* node = &root;
-  for (Args::const_iterator it = args_.begin(); it != args_.end(); ++it) {
-    const PathArgument& arg = *it;
+  for (const auto& arg : args_) {
     if (arg.kind_ == PathArgument::kindIndex) {
       if (!node->isArray() || !node->isValidIndex(arg.index_)) {
-        // Error: unable to resolve path (array value expected at position...
-        return Value::null;
+        // Error: unable to resolve path (array value expected at position... )
+        return Value::nullSingleton();
       }
       node = &((*node)[arg.index_]);
     } else if (arg.kind_ == PathArgument::kindKey) {
       if (!node->isObject()) {
         // Error: unable to resolve path (object value expected at position...)
-        return Value::null;
+        return Value::nullSingleton();
       }
       node = &((*node)[arg.key_]);
       if (node == &Value::nullSingleton()) {
         // Error: unable to resolve path (object has no member named '' at
         // position...)
-        return Value::null;
+        return Value::nullSingleton();
       }
     }
   }
@@ -4091,8 +4008,7 @@ const Value& Path::resolve(const Value& root) const {
 
 Value Path::resolve(const Value& root, const Value& defaultValue) const {
   const Value* node = &root;
-  for (Args::const_iterator it = args_.begin(); it != args_.end(); ++it) {
-    const PathArgument& arg = *it;
+  for (const auto& arg : args_) {
     if (arg.kind_ == PathArgument::kindIndex) {
       if (!node->isArray() || !node->isValidIndex(arg.index_))
         return defaultValue;
@@ -4110,8 +4026,7 @@ Value Path::resolve(const Value& root, const Value& defaultValue) const {
 
 Value& Path::make(Value& root) const {
   Value* node = &root;
-  for (Args::const_iterator it = args_.begin(); it != args_.end(); ++it) {
-    const PathArgument& arg = *it;
+  for (const auto& arg : args_) {
     if (arg.kind_ == PathArgument::kindIndex) {
       if (!node->isArray()) {
         // Error: node is not an array at position ...
@@ -4148,71 +4063,81 @@ Value& Path::make(Value& root) const {
 // See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
 
 #if !defined(JSON_IS_AMALGAMATION)
-#include <json/writer.h>
 #include "json_tool.h"
+#include <json/writer.h>
 #endif // if !defined(JSON_IS_AMALGAMATION)
+#include <algorithm>
+#include <cassert>
+#include <cctype>
+#include <cstring>
 #include <iomanip>
 #include <memory>
+#include <set>
 #include <sstream>
 #include <utility>
-#include <set>
-#include <cassert>
-#include <cstring>
+
+#if __cplusplus >= 201103L
+#include <cmath>
 #include <cstdio>
 
-#if defined(_MSC_VER) && _MSC_VER >= 1200 && _MSC_VER < 1800 // Between VC++ 6.0 and VC++ 11.0
+#if !defined(isnan)
+#define isnan std::isnan
+#endif
+
+#if !defined(isfinite)
+#define isfinite std::isfinite
+#endif
+
+#else
+#include <cmath>
+#include <cstdio>
+
+#if defined(_MSC_VER)
+#if !defined(isnan)
+#include <float.h>
+#define isnan _isnan
+#endif
+
+#if !defined(isfinite)
 #include <float.h>
 #define isfinite _finite
-#elif defined(__sun) && defined(__SVR4) //Solaris
+#endif
+
+#if !defined(_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES)
+#define _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES 1
+#endif //_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES
+
+#endif //_MSC_VER
+
+#if defined(__sun) && defined(__SVR4) // Solaris
 #if !defined(isfinite)
 #include <ieeefp.h>
 #define isfinite finite
 #endif
-#elif defined(_AIX)
-#if !defined(isfinite)
-#include <math.h>
-#define isfinite finite
 #endif
-#elif defined(__hpux)
+
+#if defined(__hpux)
 #if !defined(isfinite)
 #if defined(__ia64) && !defined(finite)
-#define isfinite(x) ((sizeof(x) == sizeof(float) ? \
-                     _Isfinitef(x) : _IsFinite(x)))
-#else
-#include <math.h>
-#define isfinite finite
-#endif
+#define isfinite(x)                                                            \
+  ((sizeof(x) == sizeof(float) ? _Isfinitef(x) : _IsFinite(x)))
 #endif
-#else
-#include <cmath>
-#if !(defined(__QNXNTO__)) // QNX already defines isfinite
-#define isfinite std::isfinite
 #endif
 #endif
 
-#if defined(_MSC_VER)
-#if !defined(WINCE) && defined(__STDC_SECURE_LIB__) && _MSC_VER >= 1500 // VC++ 9.0 and above
-#define snprintf sprintf_s
-#elif _MSC_VER >= 1900 // VC++ 14.0 and above
-#define snprintf std::snprintf
-#else
-#define snprintf _snprintf
+#if !defined(isnan)
+// IEEE standard states that NaN values will not compare to themselves
+#define isnan(x) (x != x)
 #endif
-#elif defined(__ANDROID__) || defined(__QNXNTO__)
-#define snprintf snprintf
-#elif __cplusplus >= 201103L
-#if !defined(__MINGW32__) && !defined(__CYGWIN__)
-#define snprintf std::snprintf
+
+#if !defined(__APPLE__)
+#if !defined(isfinite)
+#define isfinite finite
 #endif
 #endif
-
-#if defined(__BORLANDC__)  
-#include <float.h>
-#define isfinite _finite
-#define snprintf _snprintf
 #endif
 
-#if defined(_MSC_VER) && _MSC_VER >= 1400 // VC++ 8.0
+#if defined(_MSC_VER)
 // Disable warning about strdup being deprecated.
 #pragma warning(disable : 4996)
 #endif
@@ -4220,12 +4145,12 @@ Value& Path::make(Value& root) const {
 namespace Json {
 
 #if __cplusplus >= 201103L || (defined(_CPPLIB_VER) && _CPPLIB_VER >= 520)
-typedef std::unique_ptr<StreamWriter> StreamWriterPtr;
+using StreamWriterPtr = std::unique_ptr<StreamWriter>;
 #else
-typedef std::auto_ptr<StreamWriter>   StreamWriterPtr;
+using StreamWriterPtr = std::auto_ptr<StreamWriter>;
 #endif
 
-JSONCPP_STRING valueToString(LargestInt value) {
+String valueToString(LargestInt value) {
   UIntToStringBuffer buffer;
   char* current = buffer + sizeof(buffer);
   if (value == Value::minLargestInt) {
@@ -4241,7 +4166,7 @@ JSONCPP_STRING valueToString(LargestInt value) {
   return current;
 }
 
-JSONCPP_STRING valueToString(LargestUInt value) {
+String valueToString(LargestUInt value) {
   UIntToStringBuffer buffer;
   char* current = buffer + sizeof(buffer);
   uintToString(value, current);
@@ -4251,67 +4176,70 @@ JSONCPP_STRING valueToString(LargestUInt value) {
 
 #if defined(JSON_HAS_INT64)
 
-JSONCPP_STRING valueToString(Int value) {
-  return valueToString(LargestInt(value));
-}
+String valueToString(Int value) { return valueToString(LargestInt(value)); }
 
-JSONCPP_STRING valueToString(UInt value) {
-  return valueToString(LargestUInt(value));
-}
+String valueToString(UInt value) { return valueToString(LargestUInt(value)); }
 
 #endif // # if defined(JSON_HAS_INT64)
 
 namespace {
-JSONCPP_STRING valueToString(double value, bool useSpecialFloats, unsigned int precision) {
-  // Allocate a buffer that is more than large enough to store the 16 digits of
-  // precision requested below.
-  char buffer[36];
-  int len = -1;
-
-  char formatString[15];
-  snprintf(formatString, sizeof(formatString), "%%.%ug", precision);
-
+String valueToString(double value, bool useSpecialFloats,
+                     unsigned int precision, PrecisionType precisionType) {
   // Print into the buffer. We need not request the alternative representation
   // that always has a decimal point because JSON doesn't distinguish the
   // concepts of reals and integers.
-  if (isfinite(value)) {
-    len = snprintf(buffer, sizeof(buffer), formatString, value);
-    fixNumericLocale(buffer, buffer + len);
-
-    // try to ensure we preserve the fact that this was given to us as a double on input
-    if (!strchr(buffer, '.') && !strchr(buffer, 'e')) {
-      strcat(buffer, ".0");
+  if (!isfinite(value)) {
+    static const char* const reps[2][3] = {{"NaN", "-Infinity", "Infinity"},
+                                           {"null", "-1e+9999", "1e+9999"}};
+    return reps[useSpecialFloats ? 0 : 1]
+               [isnan(value) ? 0 : (value < 0) ? 1 : 2];
+  }
+
+  String buffer(size_t(36), '\0');
+  while (true) {
+    int len = jsoncpp_snprintf(
+        &*buffer.begin(), buffer.size(),
+        (precisionType == PrecisionType::significantDigits) ? "%.*g" : "%.*f",
+        precision, value);
+    assert(len >= 0);
+    auto wouldPrint = static_cast<size_t>(len);
+    if (wouldPrint >= buffer.size()) {
+      buffer.resize(wouldPrint + 1);
+      continue;
     }
+    buffer.resize(wouldPrint);
+    break;
+  }
 
-  } else {
-    // IEEE standard states that NaN values will not compare to themselves
-    if (value != value) {
-      len = snprintf(buffer, sizeof(buffer), useSpecialFloats ? "NaN" : "null");
-    } else if (value < 0) {
-      len = snprintf(buffer, sizeof(buffer), useSpecialFloats ? "-Infinity" : "-1e+9999");
-    } else {
-      len = snprintf(buffer, sizeof(buffer), useSpecialFloats ? "Infinity" : "1e+9999");
-    }
+  buffer.erase(fixNumericLocale(buffer.begin(), buffer.end()), buffer.end());
+
+  // strip the zero padding from the right
+  if (precisionType == PrecisionType::decimalPlaces) {
+    buffer.erase(fixZerosInTheEnd(buffer.begin(), buffer.end()), buffer.end());
+  }
+
+  // try to ensure we preserve the fact that this was given to us as a double on
+  // input
+  if (buffer.find('.') == buffer.npos && buffer.find('e') == buffer.npos) {
+    buffer += ".0";
   }
-  assert(len >= 0);
   return buffer;
 }
-}
+} // namespace
 
-JSONCPP_STRING valueToString(double value) { return valueToString(value, false, 17); }
+String valueToString(double value, unsigned int precision,
+                     PrecisionType precisionType) {
+  return valueToString(value, false, precision, precisionType);
+}
 
-JSONCPP_STRING valueToString(bool value) { return value ? "true" : "false"; }
+String valueToString(bool value) { return value ? "true" : "false"; }
 
-static bool isAnyCharRequiredQuoting(char const* s, size_t n) {
+static bool doesAnyCharRequireEscaping(char const* s, size_t n) {
   assert(s || !n);
 
-  char const* const end = s + n;
-  for (char const* cur = s; cur < end; ++cur) {
-    if (*cur == '\\' || *cur == '\"' || *cur < ' '
-      || static_cast<unsigned char>(*cur) < 0x80)
-      return true;
-  }
-  return false;
+  return std::any_of(s, s + n, [](unsigned char c) {
+    return c == '\\' || c == '"' || c < 0x20 || c > 0x7F;
+  });
 }
 
 static unsigned int utf8ToCodepoint(const char*& s, const char* e) {
@@ -4326,8 +4254,8 @@ static unsigned int utf8ToCodepoint(const char*& s, const char* e) {
     if (e - s < 2)
       return REPLACEMENT_CHARACTER;
 
-    unsigned int calculated = ((firstByte & 0x1F) << 6)
-      | (static_cast<unsigned int>(s[1]) & 0x3F);
+    unsigned int calculated =
+        ((firstByte & 0x1F) << 6) | (static_cast<unsigned int>(s[1]) & 0x3F);
     s += 1;
     // oversized encoded characters are invalid
     return calculated < 0x80 ? REPLACEMENT_CHARACTER : calculated;
@@ -4337,9 +4265,9 @@ static unsigned int utf8ToCodepoint(const char*& s, const char* e) {
     if (e - s < 3)
       return REPLACEMENT_CHARACTER;
 
-    unsigned int calculated = ((firstByte & 0x0F) << 12)
-      | ((static_cast<unsigned int>(s[1]) & 0x3F) << 6)
-      |  (static_cast<unsigned int>(s[2]) & 0x3F);
+    unsigned int calculated = ((firstByte & 0x0F) << 12) |
+                              ((static_cast<unsigned int>(s[1]) & 0x3F) << 6) |
+                              (static_cast<unsigned int>(s[2]) & 0x3F);
     s += 2;
     // surrogates aren't valid codepoints itself
     // shouldn't be UTF-8 encoded
@@ -4353,10 +4281,10 @@ static unsigned int utf8ToCodepoint(const char*& s, const char* e) {
     if (e - s < 4)
       return REPLACEMENT_CHARACTER;
 
-    unsigned int calculated = ((firstByte & 0x07) << 24)
-      | ((static_cast<unsigned int>(s[1]) & 0x3F) << 12)
-      | ((static_cast<unsigned int>(s[2]) & 0x3F) << 6)
-      |  (static_cast<unsigned int>(s[3]) & 0x3F);
+    unsigned int calculated = ((firstByte & 0x07) << 18) |
+                              ((static_cast<unsigned int>(s[1]) & 0x3F) << 12) |
+                              ((static_cast<unsigned int>(s[2]) & 0x3F) << 6) |
+                              (static_cast<unsigned int>(s[3]) & 0x3F);
     s += 3;
     // oversized encoded characters are invalid
     return calculated < 0x10000 ? REPLACEMENT_CHARACTER : calculated;
@@ -4365,28 +4293,27 @@ static unsigned int utf8ToCodepoint(const char*& s, const char* e) {
   return REPLACEMENT_CHARACTER;
 }
 
-static const char hex2[] =
-  "000102030405060708090a0b0c0d0e0f"
-  "101112131415161718191a1b1c1d1e1f"
-  "202122232425262728292a2b2c2d2e2f"
-  "303132333435363738393a3b3c3d3e3f"
-  "404142434445464748494a4b4c4d4e4f"
-  "505152535455565758595a5b5c5d5e5f"
-  "606162636465666768696a6b6c6d6e6f"
-  "707172737475767778797a7b7c7d7e7f"
-  "808182838485868788898a8b8c8d8e8f"
-  "909192939495969798999a9b9c9d9e9f"
-  "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf"
-  "b0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
-  "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
-  "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
-  "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
-  "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";
-
-static JSONCPP_STRING toHex16Bit(unsigned int x) {
+static const char hex2[] = "000102030405060708090a0b0c0d0e0f"
+                           "101112131415161718191a1b1c1d1e1f"
+                           "202122232425262728292a2b2c2d2e2f"
+                           "303132333435363738393a3b3c3d3e3f"
+                           "404142434445464748494a4b4c4d4e4f"
+                           "505152535455565758595a5b5c5d5e5f"
+                           "606162636465666768696a6b6c6d6e6f"
+                           "707172737475767778797a7b7c7d7e7f"
+                           "808182838485868788898a8b8c8d8e8f"
+                           "909192939495969798999a9b9c9d9e9f"
+                           "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf"
+                           "b0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
+                           "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
+                           "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
+                           "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
+                           "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";
+
+static String toHex16Bit(unsigned int x) {
   const unsigned int hi = (x >> 8) & 0xff;
   const unsigned int lo = x & 0xff;
-  JSONCPP_STRING result(4, ' ');
+  String result(4, ' ');
   result[0] = hex2[2 * hi];
   result[1] = hex2[2 * hi + 1];
   result[2] = hex2[2 * lo];
@@ -4394,18 +4321,26 @@ static JSONCPP_STRING toHex16Bit(unsigned int x) {
   return result;
 }
 
-static JSONCPP_STRING valueToQuotedStringN(const char* value, unsigned length) {
-  if (value == NULL)
+static void appendRaw(String& result, unsigned ch) {
+  result += static_cast<char>(ch);
+}
+
+static void appendHex(String& result, unsigned ch) {
+  result.append("\\u").append(toHex16Bit(ch));
+}
+
+static String valueToQuotedStringN(const char* value, unsigned length,
+                                   bool emitUTF8 = false) {
+  if (value == nullptr)
     return "";
 
-  if (!isAnyCharRequiredQuoting(value, length))
-    return JSONCPP_STRING("\"") + value + "\"";
+  if (!doesAnyCharRequireEscaping(value, length))
+    return String("\"") + value + "\"";
   // We have to walk value and escape any special characters.
-  // Appending to JSONCPP_STRING is not efficient, but this should be rare.
+  // Appending to String is not efficient, but this should be rare.
   // (Note: forward slashes are *not* rare, but I am not escaping them.)
-  JSONCPP_STRING::size_type maxsize =
-      length * 2 + 3; // allescaped+quotes+NULL
-  JSONCPP_STRING result;
+  String::size_type maxsize = length * 2 + 3; // allescaped+quotes+NULL
+  String result;
   result.reserve(maxsize); // to avoid lots of mallocs
   result += "\"";
   char const* end = value + length;
@@ -4441,45 +4376,50 @@ static JSONCPP_STRING valueToQuotedStringN(const char* value, unsigned length) {
     // Should add a flag to allow this compatibility mode and prevent this
     // sequence from occurring.
     default: {
-        unsigned int cp = utf8ToCodepoint(c, end);
-        // don't escape non-control characters
-        // (short escape sequence are applied above)
-        if (cp < 0x80 && cp >= 0x20)
-          result += static_cast<char>(cp);
-        else if (cp < 0x10000) { // codepoint is in Basic Multilingual Plane
-          result += "\\u";
-          result += toHex16Bit(cp);
+      if (emitUTF8) {
+        unsigned codepoint = static_cast<unsigned char>(*c);
+        if (codepoint < 0x20) {
+          appendHex(result, codepoint);
+        } else {
+          appendRaw(result, codepoint);
         }
-        else { // codepoint is not in Basic Multilingual Plane
-               // convert to surrogate pair first
-          cp -= 0x10000;
-          result += "\\u";
-          result += toHex16Bit((cp >> 10) + 0xD800);
-          result += "\\u";
-          result += toHex16Bit((cp & 0x3FF) + 0xDC00);
+      } else {
+        unsigned codepoint = utf8ToCodepoint(c, end); // modifies `c`
+        if (codepoint < 0x20) {
+          appendHex(result, codepoint);
+        } else if (codepoint < 0x80) {
+          appendRaw(result, codepoint);
+        } else if (codepoint < 0x10000) {
+          // Basic Multilingual Plane
+          appendHex(result, codepoint);
+        } else {
+          // Extended Unicode. Encode 20 bits as a surrogate pair.
+          codepoint -= 0x10000;
+          appendHex(result, 0xd800 + ((codepoint >> 10) & 0x3ff));
+          appendHex(result, 0xdc00 + (codepoint & 0x3ff));
         }
       }
-      break;
+    } break;
     }
   }
   result += "\"";
   return result;
 }
 
-JSONCPP_STRING valueToQuotedString(const char* value) {
+String valueToQuotedString(const char* value) {
   return valueToQuotedStringN(value, static_cast<unsigned int>(strlen(value)));
 }
 
 // Class Writer
 // //////////////////////////////////////////////////////////////////
-Writer::~Writer() {}
+Writer::~Writer() = default;
 
 // Class FastWriter
 // //////////////////////////////////////////////////////////////////
 
 FastWriter::FastWriter()
-    : yamlCompatibilityEnabled_(false), dropNullPlaceholders_(false),
-      omitEndingLineFeed_(false) {}
+
+    = default;
 
 void FastWriter::enableYAMLCompatibility() { yamlCompatibilityEnabled_ = true; }
 
@@ -4487,11 +4427,11 @@ void FastWriter::dropNullPlaceholders() { dropNullPlaceholders_ = true; }
 
 void FastWriter::omitEndingLineFeed() { omitEndingLineFeed_ = true; }
 
-JSONCPP_STRING FastWriter::write(const Value& root) {
+String FastWriter::write(const Value& root) {
   document_.clear();
   writeValue(root);
   if (!omitEndingLineFeed_)
-    document_ += "\n";
+    document_ += '\n';
   return document_;
 }
 
@@ -4510,13 +4450,13 @@ void FastWriter::writeValue(const Value& value) {
   case realValue:
     document_ += valueToString(value.asDouble());
     break;
-  case stringValue:
-  {
+  case stringValue: {
     // Is NULL possible for value.string_? No.
     char const* str;
     char const* end;
     bool ok = value.getString(&str, &end);
-    if (ok) document_ += valueToQuotedStringN(str, static_cast<unsigned>(end-str));
+    if (ok)
+      document_ += valueToQuotedStringN(str, static_cast<unsigned>(end - str));
     break;
   }
   case booleanValue:
@@ -4535,12 +4475,12 @@ void FastWriter::writeValue(const Value& value) {
   case objectValue: {
     Value::Members members(value.getMemberNames());
     document_ += '{';
-    for (Value::Members::iterator it = members.begin(); it != members.end();
-         ++it) {
-      const JSONCPP_STRING& name = *it;
+    for (auto it = members.begin(); it != members.end(); ++it) {
+      const String& name = *it;
       if (it != members.begin())
         document_ += ',';
-      document_ += valueToQuotedStringN(name.data(), static_cast<unsigned>(name.length()));
+      document_ += valueToQuotedStringN(name.data(),
+                                        static_cast<unsigned>(name.length()));
       document_ += yamlCompatibilityEnabled_ ? ": " : ":";
       writeValue(value[name]);
     }
@@ -4552,17 +4492,16 @@ void FastWriter::writeValue(const Value& value) {
 // Class StyledWriter
 // //////////////////////////////////////////////////////////////////
 
-StyledWriter::StyledWriter()
-    : rightMargin_(74), indentSize_(3), addChildValues_() {}
+StyledWriter::StyledWriter() = default;
 
-JSONCPP_STRING StyledWriter::write(const Value& root) {
+String StyledWriter::write(const Value& root) {
   document_.clear();
   addChildValues_ = false;
   indentString_.clear();
   writeCommentBeforeValue(root);
   writeValue(root);
   writeCommentAfterValueOnSameLine(root);
-  document_ += "\n";
+  document_ += '\n';
   return document_;
 }
 
@@ -4580,14 +4519,15 @@ void StyledWriter::writeValue(const Value& value) {
   case realValue:
     pushValue(valueToString(value.asDouble()));
     break;
-  case stringValue:
-  {
+  case stringValue: {
     // Is NULL possible for value.string_? No.
     char const* str;
     char const* end;
     bool ok = value.getString(&str, &end);
-    if (ok) pushValue(valueToQuotedStringN(str, static_cast<unsigned>(end-str)));
-    else pushValue("");
+    if (ok)
+      pushValue(valueToQuotedStringN(str, static_cast<unsigned>(end - str)));
+    else
+      pushValue("");
     break;
   }
   case booleanValue:
@@ -4603,9 +4543,9 @@ void StyledWriter::writeValue(const Value& value) {
     else {
       writeWithIndent("{");
       indent();
-      Value::Members::iterator it = members.begin();
+      auto it = members.begin();
       for (;;) {
-        const JSONCPP_STRING& name = *it;
+        const String& name = *it;
         const Value& childValue = value[name];
         writeCommentBeforeValue(childValue);
         writeWithIndent(valueToQuotedString(name.c_str()));
@@ -4675,7 +4615,7 @@ bool StyledWriter::isMultilineArray(const Value& value) {
   for (ArrayIndex index = 0; index < size && !isMultiLine; ++index) {
     const Value& childValue = value[index];
     isMultiLine = ((childValue.isArray() || childValue.isObject()) &&
-                        childValue.size() > 0);
+                   !childValue.empty());
   }
   if (!isMultiLine) // check if line length > max line length
   {
@@ -4695,7 +4635,7 @@ bool StyledWriter::isMultilineArray(const Value& value) {
   return isMultiLine;
 }
 
-void StyledWriter::pushValue(const JSONCPP_STRING& value) {
+void StyledWriter::pushValue(const String& value) {
   if (addChildValues_)
     childValues_.push_back(value);
   else
@@ -4713,12 +4653,12 @@ void StyledWriter::writeIndent() {
   document_ += indentString_;
 }
 
-void StyledWriter::writeWithIndent(const JSONCPP_STRING& value) {
+void StyledWriter::writeWithIndent(const String& value) {
   writeIndent();
   document_ += value;
 }
 
-void StyledWriter::indent() { indentString_ += JSONCPP_STRING(indentSize_, ' '); }
+void StyledWriter::indent() { indentString_ += String(indentSize_, ' '); }
 
 void StyledWriter::unindent() {
   assert(indentString_.size() >= indentSize_);
@@ -4729,20 +4669,19 @@ void StyledWriter::writeCommentBeforeValue(const Value& root) {
   if (!root.hasComment(commentBefore))
     return;
 
-  document_ += "\n";
+  document_ += '\n';
   writeIndent();
-  const JSONCPP_STRING& comment = root.getComment(commentBefore);
-  JSONCPP_STRING::const_iterator iter = comment.begin();
+  const String& comment = root.getComment(commentBefore);
+  String::const_iterator iter = comment.begin();
   while (iter != comment.end()) {
     document_ += *iter;
-    if (*iter == '\n' &&
-       ((iter+1) != comment.end() && *(iter + 1) == '/'))
+    if (*iter == '\n' && ((iter + 1) != comment.end() && *(iter + 1) == '/'))
       writeIndent();
     ++iter;
   }
 
   // Comments are stripped of trailing newlines, so add one here
-  document_ += "\n";
+  document_ += '\n';
 }
 
 void StyledWriter::writeCommentAfterValueOnSameLine(const Value& root) {
@@ -4750,9 +4689,9 @@ void StyledWriter::writeCommentAfterValueOnSameLine(const Value& root) {
     document_ += " " + root.getComment(commentAfterOnSameLine);
 
   if (root.hasComment(commentAfter)) {
-    document_ += "\n";
+    document_ += '\n';
     document_ += root.getComment(commentAfter);
-    document_ += "\n";
+    document_ += '\n';
   }
 }
 
@@ -4765,22 +4704,23 @@ bool StyledWriter::hasCommentForValue(const Value& value) {
 // Class StyledStreamWriter
 // //////////////////////////////////////////////////////////////////
 
-StyledStreamWriter::StyledStreamWriter(JSONCPP_STRING indentation)
-    : document_(NULL), rightMargin_(74), indentation_(indentation),
-      addChildValues_() {}
+StyledStreamWriter::StyledStreamWriter(String indentation)
+    : document_(nullptr), indentation_(std::move(indentation)),
+      addChildValues_(), indented_(false) {}
 
-void StyledStreamWriter::write(JSONCPP_OSTREAM& out, const Value& root) {
+void StyledStreamWriter::write(OStream& out, const Value& root) {
   document_ = &out;
   addChildValues_ = false;
   indentString_.clear();
   indented_ = true;
   writeCommentBeforeValue(root);
-  if (!indented_) writeIndent();
+  if (!indented_)
+    writeIndent();
   indented_ = true;
   writeValue(root);
   writeCommentAfterValueOnSameLine(root);
   *document_ << "\n";
-  document_ = NULL; // Forget the stream, for safety.
+  document_ = nullptr; // Forget the stream, for safety.
 }
 
 void StyledStreamWriter::writeValue(const Value& value) {
@@ -4797,14 +4737,15 @@ void StyledStreamWriter::writeValue(const Value& value) {
   case realValue:
     pushValue(valueToString(value.asDouble()));
     break;
-  case stringValue:
-  {
+  case stringValue: {
     // Is NULL possible for value.string_? No.
     char const* str;
     char const* end;
     bool ok = value.getString(&str, &end);
-    if (ok) pushValue(valueToQuotedStringN(str, static_cast<unsigned>(end-str)));
-    else pushValue("");
+    if (ok)
+      pushValue(valueToQuotedStringN(str, static_cast<unsigned>(end - str)));
+    else
+      pushValue("");
     break;
   }
   case booleanValue:
@@ -4820,9 +4761,9 @@ void StyledStreamWriter::writeValue(const Value& value) {
     else {
       writeWithIndent("{");
       indent();
-      Value::Members::iterator it = members.begin();
+      auto it = members.begin();
       for (;;) {
-        const JSONCPP_STRING& name = *it;
+        const String& name = *it;
         const Value& childValue = value[name];
         writeCommentBeforeValue(childValue);
         writeWithIndent(valueToQuotedString(name.c_str()));
@@ -4859,7 +4800,8 @@ void StyledStreamWriter::writeArrayValue(const Value& value) {
         if (hasChildValue)
           writeWithIndent(childValues_[index]);
         else {
-          if (!indented_) writeIndent();
+          if (!indented_)
+            writeIndent();
           indented_ = true;
           writeValue(childValue);
           indented_ = false;
@@ -4894,7 +4836,7 @@ bool StyledStreamWriter::isMultilineArray(const Value& value) {
   for (ArrayIndex index = 0; index < size && !isMultiLine; ++index) {
     const Value& childValue = value[index];
     isMultiLine = ((childValue.isArray() || childValue.isObject()) &&
-                        childValue.size() > 0);
+                   !childValue.empty());
   }
   if (!isMultiLine) // check if line length > max line length
   {
@@ -4914,7 +4856,7 @@ bool StyledStreamWriter::isMultilineArray(const Value& value) {
   return isMultiLine;
 }
 
-void StyledStreamWriter::pushValue(const JSONCPP_STRING& value) {
+void StyledStreamWriter::pushValue(const String& value) {
   if (addChildValues_)
     childValues_.push_back(value);
   else
@@ -4929,8 +4871,9 @@ void StyledStreamWriter::writeIndent() {
   *document_ << '\n' << indentString_;
 }
 
-void StyledStreamWriter::writeWithIndent(const JSONCPP_STRING& value) {
-  if (!indented_) writeIndent();
+void StyledStreamWriter::writeWithIndent(const String& value) {
+  if (!indented_)
+    writeIndent();
   *document_ << value;
   indented_ = false;
 }
@@ -4946,13 +4889,13 @@ void StyledStreamWriter::writeCommentBeforeValue(const Value& root) {
   if (!root.hasComment(commentBefore))
     return;
 
-  if (!indented_) writeIndent();
-  const JSONCPP_STRING& comment = root.getComment(commentBefore);
-  JSONCPP_STRING::const_iterator iter = comment.begin();
+  if (!indented_)
+    writeIndent();
+  const String& comment = root.getComment(commentBefore);
+  String::const_iterator iter = comment.begin();
   while (iter != comment.end()) {
     *document_ << *iter;
-    if (*iter == '\n' &&
-       ((iter+1) != comment.end() && *(iter + 1) == '/'))
+    if (*iter == '\n' && ((iter + 1) != comment.end() && *(iter + 1) == '/'))
       // writeIndent();  // would include newline
       *document_ << indentString_;
     ++iter;
@@ -4984,84 +4927,73 @@ bool StyledStreamWriter::hasCommentForValue(const Value& value) {
 struct CommentStyle {
   /// Decide whether to write comments.
   enum Enum {
-    None,  ///< Drop all comments.
-    Most,  ///< Recover odd behavior of previous versions (not implemented yet).
-    All  ///< Keep all comments.
+    None, ///< Drop all comments.
+    Most, ///< Recover odd behavior of previous versions (not implemented yet).
+    All   ///< Keep all comments.
   };
 };
 
-struct BuiltStyledStreamWriter : public StreamWriter
-{
-  BuiltStyledStreamWriter(
-      JSONCPP_STRING const& indentation,
-      CommentStyle::Enum cs,
-      JSONCPP_STRING const& colonSymbol,
-      JSONCPP_STRING const& nullSymbol,
-      JSONCPP_STRING const& endingLineFeedSymbol,
-      bool useSpecialFloats,
-      unsigned int precision);
-  int write(Value const& root, JSONCPP_OSTREAM* sout) JSONCPP_OVERRIDE;
+struct BuiltStyledStreamWriter : public StreamWriter {
+  BuiltStyledStreamWriter(String indentation, CommentStyle::Enum cs,
+                          String colonSymbol, String nullSymbol,
+                          String endingLineFeedSymbol, bool useSpecialFloats,
+                          bool emitUTF8, unsigned int precision,
+                          PrecisionType precisionType);
+  int write(Value const& root, OStream* sout) override;
+
 private:
   void writeValue(Value const& value);
   void writeArrayValue(Value const& value);
   bool isMultilineArray(Value const& value);
-  void pushValue(JSONCPP_STRING const& value);
+  void pushValue(String const& value);
   void writeIndent();
-  void writeWithIndent(JSONCPP_STRING const& value);
+  void writeWithIndent(String const& value);
   void indent();
   void unindent();
   void writeCommentBeforeValue(Value const& root);
   void writeCommentAfterValueOnSameLine(Value const& root);
   static bool hasCommentForValue(const Value& value);
 
-  typedef std::vector<JSONCPP_STRING> ChildValues;
+  using ChildValues = std::vector<String>;
 
   ChildValues childValues_;
-  JSONCPP_STRING indentString_;
+  String indentString_;
   unsigned int rightMargin_;
-  JSONCPP_STRING indentation_;
+  String indentation_;
   CommentStyle::Enum cs_;
-  JSONCPP_STRING colonSymbol_;
-  JSONCPP_STRING nullSymbol_;
-  JSONCPP_STRING endingLineFeedSymbol_;
+  String colonSymbol_;
+  String nullSymbol_;
+  String endingLineFeedSymbol_;
   bool addChildValues_ : 1;
   bool indented_ : 1;
   bool useSpecialFloats_ : 1;
+  bool emitUTF8_ : 1;
   unsigned int precision_;
+  PrecisionType precisionType_;
 };
 BuiltStyledStreamWriter::BuiltStyledStreamWriter(
-      JSONCPP_STRING const& indentation,
-      CommentStyle::Enum cs,
-      JSONCPP_STRING const& colonSymbol,
-      JSONCPP_STRING const& nullSymbol,
-      JSONCPP_STRING const& endingLineFeedSymbol,
-      bool useSpecialFloats,
-      unsigned int precision)
-  : rightMargin_(74)
-  , indentation_(indentation)
-  , cs_(cs)
-  , colonSymbol_(colonSymbol)
-  , nullSymbol_(nullSymbol)
-  , endingLineFeedSymbol_(endingLineFeedSymbol)
-  , addChildValues_(false)
-  , indented_(false)
-  , useSpecialFloats_(useSpecialFloats)
-  , precision_(precision)
-{
-}
-int BuiltStyledStreamWriter::write(Value const& root, JSONCPP_OSTREAM* sout)
-{
+    String indentation, CommentStyle::Enum cs, String colonSymbol,
+    String nullSymbol, String endingLineFeedSymbol, bool useSpecialFloats,
+    bool emitUTF8, unsigned int precision, PrecisionType precisionType)
+    : rightMargin_(74), indentation_(std::move(indentation)), cs_(cs),
+      colonSymbol_(std::move(colonSymbol)), nullSymbol_(std::move(nullSymbol)),
+      endingLineFeedSymbol_(std::move(endingLineFeedSymbol)),
+      addChildValues_(false), indented_(false),
+      useSpecialFloats_(useSpecialFloats), emitUTF8_(emitUTF8),
+      precision_(precision), precisionType_(precisionType) {}
+int BuiltStyledStreamWriter::write(Value const& root, OStream* sout) {
   sout_ = sout;
   addChildValues_ = false;
   indented_ = true;
   indentString_.clear();
   writeCommentBeforeValue(root);
-  if (!indented_) writeIndent();
+  if (!indented_)
+    writeIndent();
   indented_ = true;
   writeValue(root);
   writeCommentAfterValueOnSameLine(root);
   *sout_ << endingLineFeedSymbol_;
-  sout_ = NULL;
+  sout_ = nullptr;
   return 0;
 }
 void BuiltStyledStreamWriter::writeValue(Value const& value) {
@@ -5076,16 +5008,19 @@ void BuiltStyledStreamWriter::writeValue(Value const& value) {
     pushValue(valueToString(value.asLargestUInt()));
     break;
   case realValue:
-    pushValue(valueToString(value.asDouble(), useSpecialFloats_, precision_));
+    pushValue(valueToString(value.asDouble(), useSpecialFloats_, precision_,
+                            precisionType_));
     break;
-  case stringValue:
-  {
+  case stringValue: {
     // Is NULL is possible for value.string_? No.
     char const* str;
     char const* end;
     bool ok = value.getString(&str, &end);
-    if (ok) pushValue(valueToQuotedStringN(str, static_cast<unsigned>(end-str)));
-    else pushValue("");
+    if (ok)
+      pushValue(valueToQuotedStringN(str, static_cast<unsigned>(end - str),
+                                     emitUTF8_));
+    else
+      pushValue("");
     break;
   }
   case booleanValue:
@@ -5101,12 +5036,13 @@ void BuiltStyledStreamWriter::writeValue(Value const& value) {
     else {
       writeWithIndent("{");
       indent();
-      Value::Members::iterator it = members.begin();
+      auto it = members.begin();
       for (;;) {
-        JSONCPP_STRING const& name = *it;
+        String const& name = *it;
         Value const& childValue = value[name];
         writeCommentBeforeValue(childValue);
-        writeWithIndent(valueToQuotedStringN(name.data(), static_cast<unsigned>(name.length())));
+        writeWithIndent(valueToQuotedStringN(
+            name.data(), static_cast<unsigned>(name.length()), emitUTF8_));
         *sout_ << colonSymbol_;
         writeValue(childValue);
         if (++it == members.end()) {
@@ -5140,7 +5076,8 @@ void BuiltStyledStreamWriter::writeArrayValue(Value const& value) {
         if (hasChildValue)
           writeWithIndent(childValues_[index]);
         else {
-          if (!indented_) writeIndent();
+          if (!indented_)
+            writeIndent();
           indented_ = true;
           writeValue(childValue);
           indented_ = false;
@@ -5158,13 +5095,15 @@ void BuiltStyledStreamWriter::writeArrayValue(Value const& value) {
     {
       assert(childValues_.size() == size);
       *sout_ << "[";
-      if (!indentation_.empty()) *sout_ << " ";
+      if (!indentation_.empty())
+        *sout_ << " ";
       for (unsigned index = 0; index < size; ++index) {
         if (index > 0)
           *sout_ << ((!indentation_.empty()) ? ", " : ",");
         *sout_ << childValues_[index];
       }
-      if (!indentation_.empty()) *sout_ << " ";
+      if (!indentation_.empty())
+        *sout_ << " ";
       *sout_ << "]";
     }
   }
@@ -5177,7 +5116,7 @@ bool BuiltStyledStreamWriter::isMultilineArray(Value const& value) {
   for (ArrayIndex index = 0; index < size && !isMultiLine; ++index) {
     Value const& childValue = value[index];
     isMultiLine = ((childValue.isArray() || childValue.isObject()) &&
-                        childValue.size() > 0);
+                   !childValue.empty());
   }
   if (!isMultiLine) // check if line length > max line length
   {
@@ -5197,7 +5136,7 @@ bool BuiltStyledStreamWriter::isMultilineArray(Value const& value) {
   return isMultiLine;
 }
 
-void BuiltStyledStreamWriter::pushValue(JSONCPP_STRING const& value) {
+void BuiltStyledStreamWriter::pushValue(String const& value) {
   if (addChildValues_)
     childValues_.push_back(value);
   else
@@ -5216,8 +5155,9 @@ void BuiltStyledStreamWriter::writeIndent() {
   }
 }
 
-void BuiltStyledStreamWriter::writeWithIndent(JSONCPP_STRING const& value) {
-  if (!indented_) writeIndent();
+void BuiltStyledStreamWriter::writeWithIndent(String const& value) {
+  if (!indented_)
+    writeIndent();
   *sout_ << value;
   indented_ = false;
 }
@@ -5230,17 +5170,18 @@ void BuiltStyledStreamWriter::unindent() {
 }
 
 void BuiltStyledStreamWriter::writeCommentBeforeValue(Value const& root) {
-  if (cs_ == CommentStyle::None) return;
+  if (cs_ == CommentStyle::None)
+    return;
   if (!root.hasComment(commentBefore))
     return;
 
-  if (!indented_) writeIndent();
-  const JSONCPP_STRING& comment = root.getComment(commentBefore);
-  JSONCPP_STRING::const_iterator iter = comment.begin();
+  if (!indented_)
+    writeIndent();
+  const String& comment = root.getComment(commentBefore);
+  String::const_iterator iter = comment.begin();
   while (iter != comment.end()) {
     *sout_ << *iter;
-    if (*iter == '\n' &&
-       ((iter+1) != comment.end() && *(iter + 1) == '/'))
+    if (*iter == '\n' && ((iter + 1) != comment.end() && *(iter + 1) == '/'))
       // writeIndent();  // would write extra newline
       *sout_ << indentString_;
     ++iter;
@@ -5248,8 +5189,10 @@ void BuiltStyledStreamWriter::writeCommentBeforeValue(Value const& root) {
   indented_ = false;
 }
 
-void BuiltStyledStreamWriter::writeCommentAfterValueOnSameLine(Value const& root) {
-  if (cs_ == CommentStyle::None) return;
+void BuiltStyledStreamWriter::writeCommentAfterValueOnSameLine(
+    Value const& root) {
+  if (cs_ == CommentStyle::None)
+    return;
   if (root.hasComment(commentAfterOnSameLine))
     *sout_ << " " + root.getComment(commentAfterOnSameLine);
 
@@ -5269,28 +5212,19 @@ bool BuiltStyledStreamWriter::hasCommentForValue(const Value& value) {
 ///////////////
 // StreamWriter
 
-StreamWriter::StreamWriter()
-    : sout_(NULL)
-{
-}
-StreamWriter::~StreamWriter()
-{
-}
-StreamWriter::Factory::~Factory()
-{}
-StreamWriterBuilder::StreamWriterBuilder()
-{
-  setDefaults(&settings_);
-}
-StreamWriterBuilder::~StreamWriterBuilder()
-{}
-StreamWriter* StreamWriterBuilder::newStreamWriter() const
-{
-  JSONCPP_STRING indentation = settings_["indentation"].asString();
-  JSONCPP_STRING cs_str = settings_["commentStyle"].asString();
-  bool eyc = settings_["enableYAMLCompatibility"].asBool();
-  bool dnp = settings_["dropNullPlaceholders"].asBool();
-  bool usf = settings_["useSpecialFloats"].asBool(); 
+StreamWriter::StreamWriter() : sout_(nullptr) {}
+StreamWriter::~StreamWriter() = default;
+StreamWriter::Factory::~Factory() = default;
+StreamWriterBuilder::StreamWriterBuilder() { setDefaults(&settings_); }
+StreamWriterBuilder::~StreamWriterBuilder() = default;
+StreamWriter* StreamWriterBuilder::newStreamWriter() const {
+  const String indentation = settings_["indentation"].asString();
+  const String cs_str = settings_["commentStyle"].asString();
+  const String pt_str = settings_["precisionType"].asString();
+  const bool eyc = settings_["enableYAMLCompatibility"].asBool();
+  const bool dnp = settings_["dropNullPlaceholders"].asBool();
+  const bool usf = settings_["useSpecialFloats"].asBool();
+  const bool emitUTF8 = settings_["emitUTF8"].asBool();
   unsigned int pre = settings_["precision"].asUInt();
   CommentStyle::Enum cs = CommentStyle::All;
   if (cs_str == "All") {
@@ -5300,74 +5234,80 @@ StreamWriter* StreamWriterBuilder::newStreamWriter() const
   } else {
     throwRuntimeError("commentStyle must be 'All' or 'None'");
   }
-  JSONCPP_STRING colonSymbol = " : ";
+  PrecisionType precisionType(significantDigits);
+  if (pt_str == "significant") {
+    precisionType = PrecisionType::significantDigits;
+  } else if (pt_str == "decimal") {
+    precisionType = PrecisionType::decimalPlaces;
+  } else {
+    throwRuntimeError("precisionType must be 'significant' or 'decimal'");
+  }
+  String colonSymbol = " : ";
   if (eyc) {
     colonSymbol = ": ";
   } else if (indentation.empty()) {
     colonSymbol = ":";
   }
-  JSONCPP_STRING nullSymbol = "null";
+  String nullSymbol = "null";
   if (dnp) {
     nullSymbol.clear();
   }
-  if (pre > 17) pre = 17;
-  JSONCPP_STRING endingLineFeedSymbol;
-  return new BuiltStyledStreamWriter(
-      indentation, cs,
-      colonSymbol, nullSymbol, endingLineFeedSymbol, usf, pre);
-}
-static void getValidWriterKeys(std::set<JSONCPP_STRING>* valid_keys)
-{
-  valid_keys->clear();
-  valid_keys->insert("indentation");
-  valid_keys->insert("commentStyle");
-  valid_keys->insert("enableYAMLCompatibility");
-  valid_keys->insert("dropNullPlaceholders");
-  valid_keys->insert("useSpecialFloats");
-  valid_keys->insert("precision");
-}
-bool StreamWriterBuilder::validate(Json::Value* invalid) const
-{
-  Json::Value my_invalid;
-  if (!invalid) invalid = &my_invalid;  // so we do not need to test for NULL
-  Json::Value& inv = *invalid;
-  std::set<JSONCPP_STRING> valid_keys;
-  getValidWriterKeys(&valid_keys);
-  Value::Members keys = settings_.getMemberNames();
-  size_t n = keys.size();
-  for (size_t i = 0; i < n; ++i) {
-    JSONCPP_STRING const& key = keys[i];
-    if (valid_keys.find(key) == valid_keys.end()) {
-      inv[key] = settings_[key];
-    }
+  if (pre > 17)
+    pre = 17;
+  String endingLineFeedSymbol;
+  return new BuiltStyledStreamWriter(indentation, cs, colonSymbol, nullSymbol,
+                                     endingLineFeedSymbol, usf, emitUTF8, pre,
+                                     precisionType);
+}
+
+bool StreamWriterBuilder::validate(Json::Value* invalid) const {
+  static const auto& valid_keys = *new std::set<String>{
+      "indentation",
+      "commentStyle",
+      "enableYAMLCompatibility",
+      "dropNullPlaceholders",
+      "useSpecialFloats",
+      "emitUTF8",
+      "precision",
+      "precisionType",
+  };
+  for (auto si = settings_.begin(); si != settings_.end(); ++si) {
+    auto key = si.name();
+    if (valid_keys.count(key))
+      continue;
+    if (invalid)
+      (*invalid)[std::move(key)] = *si;
+    else
+      return false;
   }
-  return 0u == inv.size();
+  return invalid ? invalid->empty() : true;
 }
-Value& StreamWriterBuilder::operator[](JSONCPP_STRING key)
-{
+
+Value& StreamWriterBuilder::operator[](const String& key) {
   return settings_[key];
 }
 // static
-void StreamWriterBuilder::setDefaults(Json::Value* settings)
-{
+void StreamWriterBuilder::setDefaults(Json::Value* settings) {
   //! [StreamWriterBuilderDefaults]
   (*settings)["commentStyle"] = "All";
   (*settings)["indentation"] = "\t";
   (*settings)["enableYAMLCompatibility"] = false;
   (*settings)["dropNullPlaceholders"] = false;
   (*settings)["useSpecialFloats"] = false;
+  (*settings)["emitUTF8"] = false;
   (*settings)["precision"] = 17;
+  (*settings)["precisionType"] = "significant";
   //! [StreamWriterBuilderDefaults]
 }
 
-JSONCPP_STRING writeString(StreamWriter::Factory const& builder, Value const& root) {
-  JSONCPP_OSTRINGSTREAM sout;
-  StreamWriterPtr const writer(builder.newStreamWriter());
+String writeString(StreamWriter::Factory const& factory, Value const& root) {
+  OStringStream sout;
+  StreamWriterPtr const writer(factory.newStreamWriter());
   writer->write(root, &sout);
   return sout.str();
 }
 
-JSONCPP_OSTREAM& operator<<(JSONCPP_OSTREAM& sout, Value const& root) {
+OStream& operator<<(OStream& sout, Value const& root) {
   StreamWriterBuilder builder;
   StreamWriterPtr const writer(builder.newStreamWriter());
   writer->write(root, &sout);