/*
   Basic Unicode string class for Irrlicht.
   Copyright (c) 2009-2011 John Norman

   This software is provided 'as-is', without any express or implied
   warranty. In no event will the authors be held liable for any
   damages arising from the use of this software.

   Permission is granted to anyone to use this software for any
   purpose, including commercial applications, and to alter it and
   redistribute it freely, subject to the following restrictions:

   1. The origin of this software must not be misrepresented; you
      must not claim that you wrote the original software. If you use
      this software in a product, an acknowledgment in the product
      documentation would be appreciated but is not required.

   2. Altered source versions must be plainly marked as such, and
      must not be misrepresented as being the original software.

   3. This notice may not be removed or altered from any source
      distribution.

   The original version of this class can be located at:
   http://irrlicht.suckerfreegames.com/

   John Norman
   john@suckerfreegames.com
*/

#pragma once

#if (__cplusplus > 199711L) || (_MSC_VER >= 1600) || defined(__GXX_EXPERIMENTAL_CXX0X__)
#	define USTRING_CPP0X
#	if defined(__GXX_EXPERIMENTAL_CXX0X__) && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)))
#		define USTRING_CPP0X_NEWLITERALS
#	endif
#endif

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <cstddef>

#ifdef _WIN32
#define __BYTE_ORDER 0
#define __LITTLE_ENDIAN 0
#define __BIG_ENDIAN 1
#elif defined(__MACH__) && defined(__APPLE__)
#include <machine/endian.h>
#elif defined(__FreeBSD__) || defined(__DragonFly__)
#include <sys/endian.h>
#else
#include <endian.h>
#endif

#ifdef USTRING_CPP0X
#	include <utility>
#endif

#ifndef USTRING_NO_STL
#	include <string>
#	include <iterator>
#	include <ostream>
#endif

#include "irrTypes.h"
#include "irrAllocator.h"
#include "irrArray.h"
#include "irrMath.h"
#include "irrString.h"
#include "path.h"

//! UTF-16 surrogate start values.
static const irr::u16 UTF16_HI_SURROGATE = 0xD800;
static const irr::u16 UTF16_LO_SURROGATE = 0xDC00;

//! Is a UTF-16 code point a surrogate?
#define UTF16_IS_SURROGATE(c)		(((c) & 0xF800) == 0xD800)
#define UTF16_IS_SURROGATE_HI(c)	(((c) & 0xFC00) == 0xD800)
#define UTF16_IS_SURROGATE_LO(c)	(((c) & 0xFC00) == 0xDC00)


namespace irr
{

	// Define our character types.
#ifdef USTRING_CPP0X_NEWLITERALS	// C++0x
	typedef char32_t uchar32_t;
	typedef char16_t uchar16_t;
	typedef char uchar8_t;
#else
	typedef u32 uchar32_t;
	typedef u16 uchar16_t;
	typedef u8 uchar8_t;
#endif

namespace core
{

namespace unicode
{

//! The unicode replacement character.  Used to replace invalid characters.
const irr::u16 UTF_REPLACEMENT_CHARACTER = 0xFFFD;

//! Convert a UTF-16 surrogate pair into a UTF-32 character.
//! \param high The high value of the pair.
//! \param low The low value of the pair.
//! \return The UTF-32 character expressed by the surrogate pair.
inline uchar32_t toUTF32(uchar16_t high, uchar16_t low)
{
	// Convert the surrogate pair into a single UTF-32 character.
	uchar32_t x = ((high & ((1 << 6) -1)) << 10) | (low & ((1 << 10) -1));
	uchar32_t wu = ((high >> 6) & ((1 << 5) - 1)) + 1;
	return (wu << 16) | x;
}

//! Swaps the endianness of a 16-bit value.
//! \return The new value.
inline uchar16_t swapEndian16(const uchar16_t& c)
{
	return ((c >> 8) & 0x00FF) | ((c << 8) & 0xFF00);
}

//! Swaps the endianness of a 32-bit value.
//! \return The new value.
inline uchar32_t swapEndian32(const uchar32_t& c)
{
	return  ((c >> 24) & 0x000000FF) |
			((c >> 8)  & 0x0000FF00) |
			((c << 8)  & 0x00FF0000) |
			((c << 24) & 0xFF000000);
}

//! The Unicode byte order mark.
const u16 BOM = 0xFEFF;

//! The size of the Unicode byte order mark in terms of the Unicode character size.
const u8 BOM_UTF8_LEN = 3;
const u8 BOM_UTF16_LEN = 1;
const u8 BOM_UTF32_LEN = 1;

//! Unicode byte order marks for file operations.
const u8 BOM_ENCODE_UTF8[3] = { 0xEF, 0xBB, 0xBF };
const u8 BOM_ENCODE_UTF16_BE[2] = { 0xFE, 0xFF };
const u8 BOM_ENCODE_UTF16_LE[2] = { 0xFF, 0xFE };
const u8 BOM_ENCODE_UTF32_BE[4] = { 0x00, 0x00, 0xFE, 0xFF };
const u8 BOM_ENCODE_UTF32_LE[4] = { 0xFF, 0xFE, 0x00, 0x00 };

//! The size in bytes of the Unicode byte marks for file operations.
const u8 BOM_ENCODE_UTF8_LEN = 3;
const u8 BOM_ENCODE_UTF16_LEN = 2;
const u8 BOM_ENCODE_UTF32_LEN = 4;

//! Unicode encoding type.
enum EUTF_ENCODE
{
	EUTFE_NONE		= 0,
	EUTFE_UTF8,
	EUTFE_UTF16,
	EUTFE_UTF16_LE,
	EUTFE_UTF16_BE,
	EUTFE_UTF32,
	EUTFE_UTF32_LE,
	EUTFE_UTF32_BE
};

//! Unicode endianness.
enum EUTF_ENDIAN
{
	EUTFEE_NATIVE	= 0,
	EUTFEE_LITTLE,
	EUTFEE_BIG
};

//! Returns the specified unicode byte order mark in a byte array.
//! The byte order mark is the first few bytes in a text file that signifies its encoding.
/** \param mode The Unicode encoding method that we want to get the byte order mark for.
		If EUTFE_UTF16 or EUTFE_UTF32 is passed, it uses the native system endianness. **/
//! \return An array that contains a byte order mark.
inline core::array<u8> getUnicodeBOM(EUTF_ENCODE mode)
{
#define COPY_ARRAY(source, size) \
	memcpy(ret.pointer(), source, size); \
	ret.set_used(size)

	core::array<u8> ret(4);
	switch (mode)
	{
		case EUTFE_UTF8:
			COPY_ARRAY(BOM_ENCODE_UTF8, BOM_ENCODE_UTF8_LEN);
			break;
		case EUTFE_UTF16:
			#ifdef __BIG_ENDIAN__
				COPY_ARRAY(BOM_ENCODE_UTF16_BE, BOM_ENCODE_UTF16_LEN);
			#else
				COPY_ARRAY(BOM_ENCODE_UTF16_LE, BOM_ENCODE_UTF16_LEN);
			#endif
			break;
		case EUTFE_UTF16_BE:
			COPY_ARRAY(BOM_ENCODE_UTF16_BE, BOM_ENCODE_UTF16_LEN);
			break;
		case EUTFE_UTF16_LE:
			COPY_ARRAY(BOM_ENCODE_UTF16_LE, BOM_ENCODE_UTF16_LEN);
			break;
		case EUTFE_UTF32:
			#ifdef __BIG_ENDIAN__
				COPY_ARRAY(BOM_ENCODE_UTF32_BE, BOM_ENCODE_UTF32_LEN);
			#else
				COPY_ARRAY(BOM_ENCODE_UTF32_LE, BOM_ENCODE_UTF32_LEN);
			#endif
			break;
		case EUTFE_UTF32_BE:
			COPY_ARRAY(BOM_ENCODE_UTF32_BE, BOM_ENCODE_UTF32_LEN);
			break;
		case EUTFE_UTF32_LE:
			COPY_ARRAY(BOM_ENCODE_UTF32_LE, BOM_ENCODE_UTF32_LEN);
			break;
		case EUTFE_NONE:
			// TODO sapier: fixed warning only,
			// don't know if something needs to be done here
			break;
	}
	return ret;

#undef COPY_ARRAY
}

//! Detects if the given data stream starts with a unicode BOM.
//! \param data The data stream to check.
//! \return The unicode BOM associated with the data stream, or EUTFE_NONE if none was found.
inline EUTF_ENCODE determineUnicodeBOM(const char* data)
{
	if (memcmp(data, BOM_ENCODE_UTF8, 3) == 0) return EUTFE_UTF8;
	if (memcmp(data, BOM_ENCODE_UTF16_BE, 2) == 0) return EUTFE_UTF16_BE;
	if (memcmp(data, BOM_ENCODE_UTF16_LE, 2) == 0) return EUTFE_UTF16_LE;
	if (memcmp(data, BOM_ENCODE_UTF32_BE, 4) == 0) return EUTFE_UTF32_BE;
	if (memcmp(data, BOM_ENCODE_UTF32_LE, 4) == 0) return EUTFE_UTF32_LE;
	return EUTFE_NONE;
}

} // end namespace unicode


//! UTF-16 string class.
template <typename TAlloc = irrAllocator<uchar16_t> >
class ustring16
{
public:

	///------------------///
	/// iterator classes ///
	///------------------///

	//! Access an element in a unicode string, allowing one to change it.
	class _ustring16_iterator_access
	{
		public:
			_ustring16_iterator_access(const ustring16<TAlloc>* s, u32 p) : ref(s), pos(p) {}

			//! Allow the class to be interpreted as a single UTF-32 character.
			operator uchar32_t() const
			{
				return _get();
			}

			//! Allow one to change the character in the unicode string.
			//! \param c The new character to use.
			//! \return Myself.
			_ustring16_iterator_access& operator=(const uchar32_t c)
			{
				_set(c);
				return *this;
			}

			//! Increments the value by 1.
			//! \return Myself.
			_ustring16_iterator_access& operator++()
			{
				_set(_get() + 1);
				return *this;
			}

			//! Increments the value by 1, returning the old value.
			//! \return A unicode character.
			uchar32_t operator++(int)
			{
				uchar32_t old = _get();
				_set(old + 1);
				return old;
			}

			//! Decrements the value by 1.
			//! \return Myself.
			_ustring16_iterator_access& operator--()
			{
				_set(_get() - 1);
				return *this;
			}

			//! Decrements the value by 1, returning the old value.
			//! \return A unicode character.
			uchar32_t operator--(int)
			{
				uchar32_t old = _get();
				_set(old - 1);
				return old;
			}

			//! Adds to the value by a specified amount.
			//! \param val The amount to add to this character.
			//! \return Myself.
			_ustring16_iterator_access& operator+=(int val)
			{
				_set(_get() + val);
				return *this;
			}

			//! Subtracts from the value by a specified amount.
			//! \param val The amount to subtract from this character.
			//! \return Myself.
			_ustring16_iterator_access& operator-=(int val)
			{
				_set(_get() - val);
				return *this;
			}

			//! Multiples the value by a specified amount.
			//! \param val The amount to multiply this character by.
			//! \return Myself.
			_ustring16_iterator_access& operator*=(int val)
			{
				_set(_get() * val);
				return *this;
			}

			//! Divides the value by a specified amount.
			//! \param val The amount to divide this character by.
			//! \return Myself.
			_ustring16_iterator_access& operator/=(int val)
			{
				_set(_get() / val);
				return *this;
			}

			//! Modulos the value by a specified amount.
			//! \param val The amount to modulo this character by.
			//! \return Myself.
			_ustring16_iterator_access& operator%=(int val)
			{
				_set(_get() % val);
				return *this;
			}

			//! Adds to the value by a specified amount.
			//! \param val The amount to add to this character.
			//! \return A unicode character.
			uchar32_t operator+(int val) const
			{
				return _get() + val;
			}

			//! Subtracts from the value by a specified amount.
			//! \param val The amount to subtract from this character.
			//! \return A unicode character.
			uchar32_t operator-(int val) const
			{
				return _get() - val;
			}

			//! Multiplies the value by a specified amount.
			//! \param val The amount to multiply this character by.
			//! \return A unicode character.
			uchar32_t operator*(int val) const
			{
				return _get() * val;
			}

			//! Divides the value by a specified amount.
			//! \param val The amount to divide this character by.
			//! \return A unicode character.
			uchar32_t operator/(int val) const
			{
				return _get() / val;
			}

			//! Modulos the value by a specified amount.
			//! \param val The amount to modulo this character by.
			//! \return A unicode character.
			uchar32_t operator%(int val) const
			{
				return _get() % val;
			}

		private:
			//! Gets a uchar32_t from our current position.
			uchar32_t _get() const
			{
				const uchar16_t* a = ref->c_str();
				if (!UTF16_IS_SURROGATE(a[pos]))
					return static_cast<uchar32_t>(a[pos]);
				else
				{
					if (pos + 1 >= ref->size_raw())
						return 0;

					return unicode::toUTF32(a[pos], a[pos + 1]);
				}
			}

			//! Sets a uchar32_t at our current position.
			void _set(uchar32_t c)
			{
				ustring16<TAlloc>* ref2 = const_cast<ustring16<TAlloc>*>(ref);
				const uchar16_t* a = ref2->c_str();
				if (c > 0xFFFF)
				{
					// c will be multibyte, so split it up into the high and low surrogate pairs.
					uchar16_t x = static_cast<uchar16_t>(c);
					uchar16_t vh = UTF16_HI_SURROGATE | ((((c >> 16) & ((1 << 5) - 1)) - 1) << 6) | (x >> 10);
					uchar16_t vl = UTF16_LO_SURROGATE | (x & ((1 << 10) - 1));

					// If the previous position was a surrogate pair, just replace them.  Else, insert the low pair.
					if (UTF16_IS_SURROGATE_HI(a[pos]) && pos + 1 != ref2->size_raw())
						ref2->replace_raw(vl, static_cast<u32>(pos) + 1);
					else ref2->insert_raw(vl, static_cast<u32>(pos) + 1);

					ref2->replace_raw(vh, static_cast<u32>(pos));
				}
				else
				{
					// c will be a single byte.
					uchar16_t vh = static_cast<uchar16_t>(c);

					// If the previous position was a surrogate pair, remove the extra byte.
					if (UTF16_IS_SURROGATE_HI(a[pos]))
						ref2->erase_raw(static_cast<u32>(pos) + 1);

					ref2->replace_raw(vh, static_cast<u32>(pos));
				}
			}

			const ustring16<TAlloc>* ref;
			u32 pos;
	};
	typedef typename ustring16<TAlloc>::_ustring16_iterator_access access;


	//! Iterator to iterate through a UTF-16 string.
#ifndef USTRING_NO_STL
	class _ustring16_const_iterator : public std::iterator<
		std::bidirectional_iterator_tag,	// iterator_category
		access,								// value_type
		ptrdiff_t,							// difference_type
		const access,						// pointer
		const access						// reference
	>
#else
	class _ustring16_const_iterator
#endif
	{
		public:
			typedef _ustring16_const_iterator _Iter;
			typedef std::iterator<std::bidirectional_iterator_tag, access, ptrdiff_t, const access, const access> _Base;
			typedef const access const_pointer;
			typedef const access const_reference;

#ifndef USTRING_NO_STL
			typedef typename _Base::value_type value_type;
			typedef typename _Base::difference_type difference_type;
			typedef typename _Base::difference_type distance_type;
			typedef typename _Base::pointer pointer;
			typedef const_reference reference;
#else
			typedef access value_type;
			typedef u32 difference_type;
			typedef u32 distance_type;
			typedef const_pointer pointer;
			typedef const_reference reference;
#endif

			//! Constructors.
			_ustring16_const_iterator(const _Iter& i) : ref(i.ref), pos(i.pos) {}
			_ustring16_const_iterator(const ustring16<TAlloc>& s) : ref(&s), pos(0) {}
			_ustring16_const_iterator(const ustring16<TAlloc>& s, const u32 p) : ref(&s), pos(0)
			{
				if (ref->size_raw() == 0 || p == 0)
					return;

				// Go to the appropriate position.
				u32 i = p;
				u32 sr = ref->size_raw();
				const uchar16_t* a = ref->c_str();
				while (i != 0 && pos < sr)
				{
					if (UTF16_IS_SURROGATE_HI(a[pos]))
						pos += 2;
					else ++pos;
					--i;
				}
			}

			//! Test for equalness.
			bool operator==(const _Iter& iter) const
			{
				if (ref == iter.ref && pos == iter.pos)
					return true;
				return false;
			}

			//! Test for unequalness.
			bool operator!=(const _Iter& iter) const
			{
				if (ref != iter.ref || pos != iter.pos)
					return true;
				return false;
			}

			//! Switch to the next full character in the string.
			_Iter& operator++()
			{	// ++iterator
				if (pos == ref->size_raw()) return *this;
				const uchar16_t* a = ref->c_str();
				if (UTF16_IS_SURROGATE_HI(a[pos]))
					pos += 2;			// TODO: check for valid low surrogate?
				else ++pos;
				if (pos > ref->size_raw()) pos = ref->size_raw();
				return *this;
			}

			//! Switch to the next full character in the string, returning the previous position.
			_Iter operator++(int)
			{	// iterator++
				_Iter _tmp(*this);
				++*this;
				return _tmp;
			}

			//! Switch to the previous full character in the string.
			_Iter& operator--()
			{	// --iterator
				if (pos == 0) return *this;
				const uchar16_t* a = ref->c_str();
				--pos;
				if (UTF16_IS_SURROGATE_LO(a[pos]) && pos != 0)	// low surrogate, go back one more.
					--pos;
				return *this;
			}

			//! Switch to the previous full character in the string, returning the previous position.
			_Iter operator--(int)
			{	// iterator--
				_Iter _tmp(*this);
				--*this;
				return _tmp;
			}

			//! Advance a specified number of full characters in the string.
			//! \return Myself.
			_Iter& operator+=(const difference_type v)
			{
				if (v == 0) return *this;
				if (v < 0) return operator-=(v * -1);

				if (pos >= ref->size_raw())
					return *this;

				// Go to the appropriate position.
				// TODO: Don't force u32 on an x64 OS.  Make it agnostic.
				u32 i = (u32)v;
				u32 sr = ref->size_raw();
				const uchar16_t* a = ref->c_str();
				while (i != 0 && pos < sr)
				{
					if (UTF16_IS_SURROGATE_HI(a[pos]))
						pos += 2;
					else ++pos;
					--i;
				}
				if (pos > sr)
					pos = sr;

				return *this;
			}

			//! Go back a specified number of full characters in the string.
			//! \return Myself.
			_Iter& operator-=(const difference_type v)
			{
				if (v == 0) return *this;
				if (v > 0) return operator+=(v * -1);

				if (pos == 0)
					return *this;

				// Go to the appropriate position.
				// TODO: Don't force u32 on an x64 OS.  Make it agnostic.
				u32 i = (u32)v;
				const uchar16_t* a = ref->c_str();
				while (i != 0 && pos != 0)
				{
					--pos;
					if (UTF16_IS_SURROGATE_LO(a[pos]) != 0 && pos != 0)
						--pos;
					--i;
				}

				return *this;
			}

			//! Return a new iterator that is a variable number of full characters forward from the current position.
			_Iter operator+(const difference_type v) const
			{
				_Iter ret(*this);
				ret += v;
				return ret;
			}

			//! Return a new iterator that is a variable number of full characters backward from the current position.
			_Iter operator-(const difference_type v) const
			{
				_Iter ret(*this);
				ret -= v;
				return ret;
			}

			//! Returns the distance between two iterators.
			difference_type operator-(const _Iter& iter) const
			{
				// Make sure we reference the same object!
				if (ref != iter.ref)
					return difference_type();

				_Iter i = iter;
				difference_type ret;

				// Walk up.
				if (pos > i.pos)
				{
					while (pos > i.pos)
					{
						++i;
						++ret;
					}
					return ret;
				}

				// Walk down.
				while (pos < i.pos)
				{
					--i;
					--ret;
				}
				return ret;
			}

			//! Accesses the full character at the iterator's position.
			const_reference operator*() const
			{
				if (pos >= ref->size_raw())
				{
					const uchar16_t* a = ref->c_str();
					u32 p = ref->size_raw();
					if (UTF16_IS_SURROGATE_LO(a[p]))
						--p;
					reference ret(ref, p);
					return ret;
				}
				const_reference ret(ref, pos);
				return ret;
			}

			//! Accesses the full character at the iterator's position.
			reference operator*()
			{
				if (pos >= ref->size_raw())
				{
					const uchar16_t* a = ref->c_str();
					u32 p = ref->size_raw();
					if (UTF16_IS_SURROGATE_LO(a[p]))
						--p;
					reference ret(ref, p);
					return ret;
				}
				reference ret(ref, pos);
				return ret;
			}

			//! Accesses the full character at the iterator's position.
			const_pointer operator->() const
			{
				return operator*();
			}

			//! Accesses the full character at the iterator's position.
			pointer operator->()
			{
				return operator*();
			}

			//! Is the iterator at the start of the string?
			bool atStart() const
			{
				return pos == 0;
			}

			//! Is the iterator at the end of the string?
			bool atEnd() const
			{
				const uchar16_t* a = ref->c_str();
				if (UTF16_IS_SURROGATE(a[pos]))
					return (pos + 1) >= ref->size_raw();
				else return pos >= ref->size_raw();
			}

			//! Moves the iterator to the start of the string.
			void toStart()
			{
				pos = 0;
			}

			//! Moves the iterator to the end of the string.
			void toEnd()
			{
				pos = ref->size_raw();
			}

			//! Returns the iterator's position.
			//! \return The iterator's position.
			u32 getPos() const
			{
				return pos;
			}

		protected:
			const ustring16<TAlloc>* ref;
			u32 pos;
	};

	//! Iterator to iterate through a UTF-16 string.
	class _ustring16_iterator : public _ustring16_const_iterator
	{
		public:
			typedef _ustring16_iterator _Iter;
			typedef _ustring16_const_iterator _Base;
			typedef typename _Base::const_pointer const_pointer;
			typedef typename _Base::const_reference const_reference;


			typedef typename _Base::value_type value_type;
			typedef typename _Base::difference_type difference_type;
			typedef typename _Base::distance_type distance_type;
			typedef access pointer;
			typedef access reference;

			using _Base::pos;
			using _Base::ref;

			//! Constructors.
			_ustring16_iterator(const _Iter& i) : _ustring16_const_iterator(i) {}
			_ustring16_iterator(const ustring16<TAlloc>& s) : _ustring16_const_iterator(s) {}
			_ustring16_iterator(const ustring16<TAlloc>& s, const u32 p) : _ustring16_const_iterator(s, p) {}

			//! Accesses the full character at the iterator's position.
			reference operator*() const
			{
				if (pos >= ref->size_raw())
				{
					const uchar16_t* a = ref->c_str();
					u32 p = ref->size_raw();
					if (UTF16_IS_SURROGATE_LO(a[p]))
						--p;
					reference ret(ref, p);
					return ret;
				}
				reference ret(ref, pos);
				return ret;
			}

			//! Accesses the full character at the iterator's position.
			reference operator*()
			{
				if (pos >= ref->size_raw())
				{
					const uchar16_t* a = ref->c_str();
					u32 p = ref->size_raw();
					if (UTF16_IS_SURROGATE_LO(a[p]))
						--p;
					reference ret(ref, p);
					return ret;
				}
				reference ret(ref, pos);
				return ret;
			}

			//! Accesses the full character at the iterator's position.
			pointer operator->() const
			{
				return operator*();
			}

			//! Accesses the full character at the iterator's position.
			pointer operator->()
			{
				return operator*();
			}
	};

	typedef typename ustring16<TAlloc>::_ustring16_iterator iterator;
	typedef typename ustring16<TAlloc>::_ustring16_const_iterator const_iterator;

	///----------------------///
	/// end iterator classes ///
	///----------------------///

	//! Default constructor
	ustring16()
	: array(0), allocated(1), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif
		array = allocator.allocate(1); // new u16[1];
		array[0] = 0x0;
	}


	//! Constructor
	ustring16(const ustring16<TAlloc>& other)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif
		*this = other;
	}


	//! Constructor from other string types
	template <class B, class A>
	ustring16(const string<B, A>& other)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif
		*this = other;
	}


#ifndef USTRING_NO_STL
	//! Constructor from std::string
	template <class B, class A, typename Alloc>
	ustring16(const std::basic_string<B, A, Alloc>& other)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif
		*this = other.c_str();
	}


	//! Constructor from iterator.
	template <typename Itr>
	ustring16(Itr first, Itr last)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif
		reserve(std::distance(first, last));
		array[used] = 0;

		for (; first != last; ++first)
			append((uchar32_t)*first);
	}
#endif


#ifndef USTRING_CPP0X_NEWLITERALS
	//! Constructor for copying a character string from a pointer.
	ustring16(const char* const c)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif

		loadDataStream(c, strlen(c));
		//append((uchar8_t*)c);
	}


	//! Constructor for copying a character string from a pointer with a given length.
	ustring16(const char* const c, u32 length)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif

		loadDataStream(c, length);
	}
#endif


	//! Constructor for copying a UTF-8 string from a pointer.
	ustring16(const uchar8_t* const c)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif

		append(c);
	}


	//! Constructor for copying a UTF-8 string from a single char.
	ustring16(const char c)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif

		append((uchar32_t)c);
	}


	//! Constructor for copying a UTF-8 string from a pointer with a given length.
	ustring16(const uchar8_t* const c, u32 length)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif

		append(c, length);
	}


	//! Constructor for copying a UTF-16 string from a pointer.
	ustring16(const uchar16_t* const c)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif

		append(c);
	}


	//! Constructor for copying a UTF-16 string from a pointer with a given length
	ustring16(const uchar16_t* const c, u32 length)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif

		append(c, length);
	}


	//! Constructor for copying a UTF-32 string from a pointer.
	ustring16(const uchar32_t* const c)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif

		append(c);
	}


	//! Constructor for copying a UTF-32 from a pointer with a given length.
	ustring16(const uchar32_t* const c, u32 length)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif

		append(c, length);
	}


	//! Constructor for copying a wchar_t string from a pointer.
	ustring16(const wchar_t* const c)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif

		if (sizeof(wchar_t) == 4)
			append(reinterpret_cast<const uchar32_t* const>(c));
		else if (sizeof(wchar_t) == 2)
			append(reinterpret_cast<const uchar16_t* const>(c));
		else if (sizeof(wchar_t) == 1)
			append(reinterpret_cast<const uchar8_t* const>(c));
	}


	//! Constructor for copying a wchar_t string from a pointer with a given length.
	ustring16(const wchar_t* const c, u32 length)
	: array(0), allocated(0), used(0)
	{
#if __BYTE_ORDER == __BIG_ENDIAN
		encoding = unicode::EUTFE_UTF16_BE;
#else
		encoding = unicode::EUTFE_UTF16_LE;
#endif

		if (sizeof(wchar_t) == 4)
			append(reinterpret_cast<const uchar32_t* const>(c), length);
		else if (sizeof(wchar_t) == 2)
			append(reinterpret_cast<const uchar16_t* const>(c), length);
		else if (sizeof(wchar_t) == 1)
			append(reinterpret_cast<const uchar8_t* const>(c), length);
	}


#ifdef USTRING_CPP0X
	//! Constructor for moving a ustring16
	ustring16(ustring16<TAlloc>&& other)
	: array(other.array), encoding(other.encoding), allocated(other.allocated), used(other.used)
	{
		//std::cout << "MOVE constructor" << std::endl;
		other.array = 0;
		other.allocated = 0;
		other.used = 0;
	}
#endif


	//! Destructor
	~ustring16()
	{
		allocator.deallocate(array); // delete [] array;
	}


	//! Assignment operator
	ustring16& operator=(const ustring16<TAlloc>& other)
	{
		if (this == &other)
			return *this;

		used = other.size_raw();
		if (used >= allocated)
		{
			allocator.deallocate(array); // delete [] array;
			allocated = used + 1;
			array = allocator.allocate(used + 1); //new u16[used];
		}

		const uchar16_t* p = other.c_str();
		for (u32 i=0; i<=used; ++i, ++p)
			array[i] = *p;

		array[used] = 0;

		// Validate our new UTF-16 string.
		validate();

		return *this;
	}


#ifdef USTRING_CPP0X
	//! Move assignment operator
	ustring16& operator=(ustring16<TAlloc>&& other)
	{
		if (this != &other)
		{
			//std::cout << "MOVE operator=" << std::endl;
			allocator.deallocate(array);

			array = other.array;
			allocated = other.allocated;
			encoding = other.encoding;
			used = other.used;
			other.array = 0;
			other.used = 0;
		}
		return *this;
	}
#endif


	//! Assignment operator for other string types
	template <class B, class A>
	ustring16<TAlloc>& operator=(const string<B, A>& other)
	{
		*this = other.c_str();
		return *this;
	}


	//! Assignment operator for UTF-8 strings
	ustring16<TAlloc>& operator=(const uchar8_t* const c)
	{
		if (!array)
		{
			array = allocator.allocate(1); //new u16[1];
			allocated = 1;
		}
		used = 0;
		array[used] = 0x0;
		if (!c) return *this;

		//! Append our string now.
		append(c);
		return *this;
	}


	//! Assignment operator for UTF-16 strings
	ustring16<TAlloc>& operator=(const uchar16_t* const c)
	{
		if (!array)
		{
			array = allocator.allocate(1); //new u16[1];
			allocated = 1;
		}
		used = 0;
		array[used] = 0x0;
		if (!c) return *this;

		//! Append our string now.
		append(c);
		return *this;
	}


	//! Assignment operator for UTF-32 strings
	ustring16<TAlloc>& operator=(const uchar32_t* const c)
	{
		if (!array)
		{
			array = allocator.allocate(1); //new u16[1];
			allocated = 1;
		}
		used = 0;
		array[used] = 0x0;
		if (!c) return *this;

		//! Append our string now.
		append(c);
		return *this;
	}


	//! Assignment operator for wchar_t strings.
	/** Note that this assumes that a correct unicode string is stored in the wchar_t string.
		Since wchar_t changes depending on its platform, it could either be a UTF-8, -16, or -32 string.
		This function assumes you are storing the correct unicode encoding inside the wchar_t string. **/
	ustring16<TAlloc>& operator=(const wchar_t* const c)
	{
		if (sizeof(wchar_t) == 4)
			*this = reinterpret_cast<const uchar32_t* const>(c);
		else if (sizeof(wchar_t) == 2)
			*this = reinterpret_cast<const uchar16_t* const>(c);
		else if (sizeof(wchar_t) == 1)
			*this = reinterpret_cast<const uchar8_t* const>(c);

		return *this;
	}


	//! Assignment operator for other strings.
	/** Note that this assumes that a correct unicode string is stored in the string. **/
	template <class B>
	ustring16<TAlloc>& operator=(const B* const c)
	{
		if (sizeof(B) == 4)
			*this = reinterpret_cast<const uchar32_t* const>(c);
		else if (sizeof(B) == 2)
			*this = reinterpret_cast<const uchar16_t* const>(c);
		else if (sizeof(B) == 1)
			*this = reinterpret_cast<const uchar8_t* const>(c);

		return *this;
	}


	//! Direct access operator
	access operator [](const u32 index)
	{
		_IRR_DEBUG_BREAK_IF(index>=size()) // bad index
		iterator iter(*this, index);
		return iter.operator*();
	}


	//! Direct access operator
	const access operator [](const u32 index) const
	{
		_IRR_DEBUG_BREAK_IF(index>=size()) // bad index
		const_iterator iter(*this, index);
		return iter.operator*();
	}


	//! Equality operator
	bool operator ==(const uchar16_t* const str) const
	{
		if (!str)
			return false;

		u32 i;
		for(i=0; array[i] && str[i]; ++i)
			if (array[i] != str[i])
				return false;

		return !array[i] && !str[i];
	}


	//! Equality operator
	bool operator ==(const ustring16<TAlloc>& other) const
	{
		for(u32 i=0; array[i] && other.array[i]; ++i)
			if (array[i] != other.array[i])
				return false;

		return used == other.used;
	}


	//! Is smaller comparator
	bool operator <(const ustring16<TAlloc>& other) const
	{
		for(u32 i=0; array[i] && other.array[i]; ++i)
		{
			s32 diff = array[i] - other.array[i];
			if ( diff )
				return diff < 0;
		}

		return used < other.used;
	}


	//! Inequality operator
	bool operator !=(const uchar16_t* const str) const
	{
		return !(*this == str);
	}


	//! Inequality operator
	bool operator !=(const ustring16<TAlloc>& other) const
	{
		return !(*this == other);
	}


	//! Returns the length of a ustring16 in full characters.
	//! \return Length of a ustring16 in full characters.
	u32 size() const
	{
		const_iterator i(*this, 0);
		u32 pos = 0;
		while (!i.atEnd())
		{
			++i;
			++pos;
		}
		return pos;
	}


	//! Informs if the ustring is empty or not.
	//! \return True if the ustring is empty, false if not.
	bool empty() const
	{
		return (size_raw() == 0);
	}


	//! Returns a pointer to the raw UTF-16 string data.
	//! \return pointer to C-style NUL terminated array of UTF-16 code points.
	const uchar16_t* c_str() const
	{
		return array;
	}


	//! Compares the first n characters of this string with another.
	//! \param other Other string to compare to.
	//! \param n Number of characters to compare.
	//! \return True if the n first characters of both strings are equal.
	bool equalsn(const ustring16<TAlloc>& other, u32 n) const
	{
		u32 i;
		const uchar16_t* oa = other.c_str();
		for(i=0; i < n && array[i] && oa[i]; ++i)
			if (array[i] != oa[i])
				return false;

		// if one (or both) of the strings was smaller then they
		// are only equal if they have the same length
		return (i == n) || (used == other.used);
	}


	//! Compares the first n characters of this string with another.
	//! \param str Other string to compare to.
	//! \param n Number of characters to compare.
	//! \return True if the n first characters of both strings are equal.
	bool equalsn(const uchar16_t* const str, u32 n) const
	{
		if (!str)
			return false;
		u32 i;
		for(i=0; i < n && array[i] && str[i]; ++i)
			if (array[i] != str[i])
				return false;

		// if one (or both) of the strings was smaller then they
		// are only equal if they have the same length
		return (i == n) || (array[i] == 0 && str[i] == 0);
	}


	//! Appends a character to this ustring16
	//! \param character The character to append.
	//! \return A reference to our current string.
	ustring16<TAlloc>& append(uchar32_t character)
	{
		if (used + 2 >= allocated)
			reallocate(used + 2);

		if (character > 0xFFFF)
		{
			used += 2;

			// character will be multibyte, so split it up into a surrogate pair.
			uchar16_t x = static_cast<uchar16_t>(character);
			uchar16_t vh = UTF16_HI_SURROGATE | ((((character >> 16) & ((1 << 5) - 1)) - 1) << 6) | (x >> 10);
			uchar16_t vl = UTF16_LO_SURROGATE | (x & ((1 << 10) - 1));
			array[used-2] = vh;
			array[used-1] = vl;
		}
		else
		{
			++used;
			array[used-1] = character;
		}
		array[used] = 0;

		return *this;
	}


	//! Appends a UTF-8 string to this ustring16
	//! \param other The UTF-8 string to append.
	//! \param length The length of the string to append.
	//! \return A reference to our current string.
	ustring16<TAlloc>& append(const uchar8_t* const other, u32 length=0xffffffff)
	{
		if (!other)
			return *this;

		// Determine if the string is long enough for a BOM.
		u32 len = 0;
		const uchar8_t* p = other;
		do
		{
			++len;
		} while (*p++ && len < unicode::BOM_ENCODE_UTF8_LEN);

		// Check for BOM.
		unicode::EUTF_ENCODE c_bom = unicode::EUTFE_NONE;
		if (len == unicode::BOM_ENCODE_UTF8_LEN)
		{
			if (memcmp(other, unicode::BOM_ENCODE_UTF8, unicode::BOM_ENCODE_UTF8_LEN) == 0)
				c_bom = unicode::EUTFE_UTF8;
		}

		// If a BOM was found, don't include it in the string.
		const uchar8_t* c2 = other;
		if (c_bom != unicode::EUTFE_NONE)
		{
			c2 = other + unicode::BOM_UTF8_LEN;
			length -= unicode::BOM_UTF8_LEN;
		}

		// Calculate the size of the string to read in.
		len = 0;
		p = c2;
		do
		{
			++len;
		} while(*p++ && len < length);
		if (len > length)
			len = length;

		// If we need to grow the array, do it now.
		if (used + len >= allocated)
			reallocate(used + (len * 2));
		u32 start = used;

		// Convert UTF-8 to UTF-16.
		u32 pos = start;
		for (u32 l = 0; l<len;)
		{
			++used;
			if (((c2[l] >> 6) & 0x03) == 0x02)
			{	// Invalid continuation byte.
				array[pos++] = unicode::UTF_REPLACEMENT_CHARACTER;
				++l;
			}
			else if (c2[l] == 0xC0 || c2[l] == 0xC1)
			{	// Invalid byte - overlong encoding.
				array[pos++] = unicode::UTF_REPLACEMENT_CHARACTER;
				++l;
			}
			else if ((c2[l] & 0xF8) == 0xF0)
			{	// 4 bytes UTF-8, 2 bytes UTF-16.
				// Check for a full string.
				if ((l + 3) >= len)
				{
					array[pos++] = unicode::UTF_REPLACEMENT_CHARACTER;
					l += 3;
					break;
				}

				// Validate.
				bool valid = true;
				u8 l2 = 0;
				if (valid && (((c2[l+1] >> 6) & 0x03) == 0x02)) ++l2; else valid = false;
				if (valid && (((c2[l+2] >> 6) & 0x03) == 0x02)) ++l2; else valid = false;
				if (valid && (((c2[l+3] >> 6) & 0x03) == 0x02)) ++l2; else valid = false;
				if (!valid)
				{
					array[pos++] = unicode::UTF_REPLACEMENT_CHARACTER;
					l += l2;
					continue;
				}

				// Decode.
				uchar8_t b1 = ((c2[l] & 0x7) << 2) | ((c2[l+1] >> 4) & 0x3);
				uchar8_t b2 = ((c2[l+1] & 0xF) << 4) | ((c2[l+2] >> 2) & 0xF);
				uchar8_t b3 = ((c2[l+2] & 0x3) << 6) | (c2[l+3] & 0x3F);
				uchar32_t v = b3 | ((uchar32_t)b2 << 8) | ((uchar32_t)b1 << 16);

				// Split v up into a surrogate pair.
				uchar16_t x = static_cast<uchar16_t>(v);
				uchar16_t vh = UTF16_HI_SURROGATE | ((((v >> 16) & ((1 << 5) - 1)) - 1) << 6) | (x >> 10);
				uchar16_t vl = UTF16_LO_SURROGATE | (x & ((1 << 10) - 1));

				array[pos++] = vh;
				array[pos++] = vl;
				l += 4;
				++used;		// Using two shorts this time, so increase used by 1.
			}
			else if ((c2[l] & 0xF0) == 0xE0)
			{	// 3 bytes UTF-8, 1 byte UTF-16.
				// Check for a full string.
				if ((l + 2) >= len)
				{
					array[pos++] = unicode::UTF_REPLACEMENT_CHARACTER;
					l += 2;
					break;
				}

				// Validate.
				bool valid = true;
				u8 l2 = 0;
				if (valid && (((c2[l+1] >> 6) & 0x03) == 0x02)) ++l2; else valid = false;
				if (valid && (((c2[l+2] >> 6) & 0x03) == 0x02)) ++l2; else valid = false;
				if (!valid)
				{
					array[pos++] = unicode::UTF_REPLACEMENT_CHARACTER;
					l += l2;
					continue;
				}

				// Decode.
				uchar8_t b1 = ((c2[l] & 0xF) << 4) | ((c2[l+1] >> 2) & 0xF);
				uchar8_t b2 = ((c2[l+1] & 0x3) << 6) | (c2[l+2] & 0x3F);
				uchar16_t ch = b2 | ((uchar16_t)b1 << 8);
				array[pos++] = ch;
				l += 3;
			}
			else if ((c2[l] & 0xE0) == 0xC0)
			{	// 2 bytes UTF-8, 1 byte UTF-16.
				// Check for a full string.
				if ((l + 1) >= len)
				{
					array[pos++] = unicode::UTF_REPLACEMENT_CHARACTER;
					l += 1;
					break;
				}

				// Validate.
				if (((c2[l+1] >> 6) & 0x03) != 0x02)
				{
					array[pos++] = unicode::UTF_REPLACEMENT_CHARACTER;
					++l;
					continue;
				}

				// Decode.
				uchar8_t b1 = (c2[l] >> 2) & 0x7;
				uchar8_t b2 = ((c2[l] & 0x3) << 6) | (c2[l+1] & 0x3F);
				uchar16_t ch = b2 | ((uchar16_t)b1 << 8);
				array[pos++] = ch;
				l += 2;
			}
			else
			{	// 1 byte UTF-8, 1 byte UTF-16.
				// Validate.
				if (c2[l] > 0x7F)
				{	// Values above 0xF4 are restricted and aren't used.  By now, anything above 0x7F is invalid.
					array[pos++] = unicode::UTF_REPLACEMENT_CHARACTER;
				}
				else array[pos++] = static_cast<uchar16_t>(c2[l]);
				++l;
			}
		}
		array[used] = 0;

		// Validate our new UTF-16 string.
		validate();

		return *this;
	}


	//! Appends a UTF-16 string to this ustring16
	//! \param other The UTF-16 string to append.
	//! \param length The length of the string to append.
	//! \return A reference to our current string.
	ustring16<TAlloc>& append(const uchar16_t* const other, u32 length=0xffffffff)
	{
		if (!other)
			return *this;

		// Determine if the string is long enough for a BOM.
		u32 len = 0;
		const uchar16_t* p = other;
		do
		{
			++len;
		} while (*p++ && len < unicode::BOM_ENCODE_UTF16_LEN);

		// Check for the BOM to determine the string's endianness.
		unicode::EUTF_ENDIAN c_end = unicode::EUTFEE_NATIVE;
		if (memcmp(other, unicode::BOM_ENCODE_UTF16_LE, unicode::BOM_ENCODE_UTF16_LEN) == 0)
			c_end = unicode::EUTFEE_LITTLE;
		else if (memcmp(other, unicode::BOM_ENCODE_UTF16_BE, unicode::BOM_ENCODE_UTF16_LEN) == 0)
			c_end = unicode::EUTFEE_BIG;

		// If a BOM was found, don't include it in the string.
		const uchar16_t* c2 = other;
		if (c_end != unicode::EUTFEE_NATIVE)
		{
			c2 = other + unicode::BOM_UTF16_LEN;
			length -= unicode::BOM_UTF16_LEN;
		}

		// Calculate the size of the string to read in.
		len = 0;
		p = c2;
		do
		{
			++len;
		} while(*p++ && len < length);
		if (len > length)
			len = length;

		// If we need to grow the size of the array, do it now.
		if (used + len >= allocated)
			reallocate(used + (len * 2));
		u32 start = used;
		used += len;

		// Copy the string now.
		unicode::EUTF_ENDIAN m_end = getEndianness();
		for (u32 l = start; l < start + len; ++l)
		{
			array[l] = (uchar16_t)c2[l];
			if (c_end != unicode::EUTFEE_NATIVE && c_end != m_end)
				array[l] = unicode::swapEndian16(array[l]);
		}

		array[used] = 0;

		// Validate our new UTF-16 string.
		validate();
		return *this;
	}


	//! Appends a UTF-32 string to this ustring16
	//! \param other The UTF-32 string to append.
	//! \param length The length of the string to append.
	//! \return A reference to our current string.
	ustring16<TAlloc>& append(const uchar32_t* const other, u32 length=0xffffffff)
	{
		if (!other)
			return *this;

		// Check for the BOM to determine the string's endianness.
		unicode::EUTF_ENDIAN c_end = unicode::EUTFEE_NATIVE;
		if (memcmp(other, unicode::BOM_ENCODE_UTF32_LE, unicode::BOM_ENCODE_UTF32_LEN) == 0)
			c_end = unicode::EUTFEE_LITTLE;
		else if (memcmp(other, unicode::BOM_ENCODE_UTF32_BE, unicode::BOM_ENCODE_UTF32_LEN) == 0)
			c_end = unicode::EUTFEE_BIG;

		// If a BOM was found, don't include it in the string.
		const uchar32_t* c2 = other;
		if (c_end != unicode::EUTFEE_NATIVE)
		{
			c2 = other + unicode::BOM_UTF32_LEN;
			length -= unicode::BOM_UTF32_LEN;
		}

		// Calculate the size of the string to read in.
		u32 len = 0;
		const uchar32_t* p = c2;
		do
		{
			++len;
		} while(*p++ && len < length);
		if (len > length)
			len = length;

		// If we need to grow the size of the array, do it now.
		// In case all of the UTF-32 string is split into surrogate pairs, do len * 2.
		if (used + (len * 2) >= allocated)
			reallocate(used + ((len * 2) * 2));
		u32 start = used;

		// Convert UTF-32 to UTF-16.
		unicode::EUTF_ENDIAN m_end = getEndianness();
		u32 pos = start;
		for (u32 l = 0; l<len; ++l)
		{
			++used;

			uchar32_t ch = c2[l];
			if (c_end != unicode::EUTFEE_NATIVE && c_end != m_end)
				ch = unicode::swapEndian32(ch);

			if (ch > 0xFFFF)
			{
				// Split ch up into a surrogate pair as it is over 16 bits long.
				uchar16_t x = static_cast<uchar16_t>(ch);
				uchar16_t vh = UTF16_HI_SURROGATE | ((((ch >> 16) & ((1 << 5) - 1)) - 1) << 6) | (x >> 10);
				uchar16_t vl = UTF16_LO_SURROGATE | (x & ((1 << 10) - 1));
				array[pos++] = vh;
				array[pos++] = vl;
				++used;		// Using two shorts, so increased used again.
			}
			else if (ch >= 0xD800 && ch <= 0xDFFF)
			{
				// Between possible UTF-16 surrogates (invalid!)
				array[pos++] = unicode::UTF_REPLACEMENT_CHARACTER;
			}
			else array[pos++] = static_cast<uchar16_t>(ch);
		}
		array[used] = 0;

		// Validate our new UTF-16 string.
		validate();

		return *this;
	}


	//! Appends a ustring16 to this ustring16
	//! \param other The string to append to this one.
	//! \return A reference to our current string.
	ustring16<TAlloc>& append(const ustring16<TAlloc>& other)
	{
		const uchar16_t* oa = other.c_str();

		u32 len = other.size_raw();

		if (used + len >= allocated)
			reallocate(used + len);

		for (u32 l=0; l<len; ++l)
			array[used+l] = oa[l];

		used += len;
		array[used] = 0;

		return *this;
	}


	//! Appends a certain amount of characters of a ustring16 to this ustring16.
	//! \param other The string to append to this one.
	//! \param length How many characters of the other string to add to this one.
	//! \return A reference to our current string.
	ustring16<TAlloc>& append(const ustring16<TAlloc>& other, u32 length)
	{
		if (other.size() == 0)
			return *this;

		if (other.size() < length)
		{
			append(other);
			return *this;
		}

		if (used + length * 2 >= allocated)
			reallocate(used + length * 2);

		const_iterator iter(other, 0);
		u32 l = length;
		while (!iter.atEnd() && l)
		{
			uchar32_t c = *iter;
			append(c);
			++iter;
			--l;
		}

		return *this;
	}


	//! Reserves some memory.
	//! \param count The amount of characters to reserve.
	void reserve(u32 count)
	{
		if (count < allocated)
			return;

		reallocate(count);
	}


	//! Finds first occurrence of character.
	//! \param c The character to search for.
	//! \return Position where the character has been found, or -1 if not found.
	s32 findFirst(uchar32_t c) const
	{
		const_iterator i(*this, 0);

		s32 pos = 0;
		while (!i.atEnd())
		{
			uchar32_t t = *i;
			if (c == t)
				return pos;
			++pos;
			++i;
		}

		return -1;
	}

	//! Finds first occurrence of a character of a list.
	//! \param c A list of characters to find. For example if the method should find the first occurrence of 'a' or 'b', this parameter should be "ab".
	//! \param count The amount of characters in the list. Usually, this should be strlen(c).
	//! \return Position where one of the characters has been found, or -1 if not found.
	s32 findFirstChar(const uchar32_t* const c, u32 count=1) const
	{
		if (!c || !count)
			return -1;

		const_iterator i(*this, 0);

		s32 pos = 0;
		while (!i.atEnd())
		{
			uchar32_t t = *i;
			for (u32 j=0; j<count; ++j)
				if (t == c[j])
					return pos;
			++pos;
			++i;
		}

		return -1;
	}


	//! Finds first position of a character not in a given list.
	//! \param c A list of characters to NOT find. For example if the method should find the first occurrence of a character not 'a' or 'b', this parameter should be "ab".
	//! \param count The amount of characters in the list. Usually, this should be strlen(c).
	//! \return Position where the character has been found, or -1 if not found.
	s32 findFirstCharNotInList(const uchar32_t* const c, u32 count=1) const
	{
		if (!c || !count)
			return -1;

		const_iterator i(*this, 0);

		s32 pos = 0;
		while (!i.atEnd())
		{
			uchar32_t t = *i;
			u32 j;
			for (j=0; j<count; ++j)
				if (t == c[j])
					break;

			if (j==count)
				return pos;
			++pos;
			++i;
		}

		return -1;
	}

	//! Finds last position of a character not in a given list.
	//! \param c A list of characters to NOT find. For example if the method should find the first occurrence of a character not 'a' or 'b', this parameter should be "ab".
	//! \param count The amount of characters in the list. Usually, this should be strlen(c).
	//! \return Position where the character has been found, or -1 if not found.
	s32 findLastCharNotInList(const uchar32_t* const c, u32 count=1) const
	{
		if (!c || !count)
			return -1;

		const_iterator i(end());
		--i;

		s32 pos = size() - 1;
		while (!i.atStart())
		{
			uchar32_t t = *i;
			u32 j;
			for (j=0; j<count; ++j)
				if (t == c[j])
					break;

			if (j==count)
				return pos;
			--pos;
			--i;
		}

		return -1;
	}

	//! Finds next occurrence of character.
	//! \param c The character to search for.
	//! \param startPos The position in the string to start searching.
	//! \return Position where the character has been found, or -1 if not found.
	s32 findNext(uchar32_t c, u32 startPos) const
	{
		const_iterator i(*this, startPos);

		s32 pos = startPos;
		while (!i.atEnd())
		{
			uchar32_t t = *i;
			if (t == c)
				return pos;
			++pos;
			++i;
		}

		return -1;
	}


	//! Finds last occurrence of character.
	//! \param c The character to search for.
	//! \param start The start position of the reverse search ( default = -1, on end ).
	//! \return Position where the character has been found, or -1 if not found.
	s32 findLast(uchar32_t c, s32 start = -1) const
	{
		u32 s = size();
		start = core::clamp ( start < 0 ? (s32)s : start, 0, (s32)s ) - 1;

		const_iterator i(*this, start);
		u32 pos = start;
		while (!i.atStart())
		{
			uchar32_t t = *i;
			if (t == c)
				return pos;
			--pos;
			--i;
		}

		return -1;
	}

	//! Finds last occurrence of a character in a list.
	//! \param c A list of strings to find. For example if the method should find the last occurrence of 'a' or 'b', this parameter should be "ab".
	//! \param count The amount of characters in the list. Usually, this should be strlen(c).
	//! \return Position where one of the characters has been found, or -1 if not found.
	s32 findLastChar(const uchar32_t* const c, u32 count=1) const
	{
		if (!c || !count)
			return -1;

		const_iterator i(end());
		--i;

		s32 pos = size();
		while (!i.atStart())
		{
			uchar32_t t = *i;
			for (u32 j=0; j<count; ++j)
				if (t == c[j])
					return pos;