gistfile1.txt

#pragma once

#include <fstream>
#include <codecvt>

class Windows_UTF_Converter
{
public:
#ifdef WIN32
	std::string utf8_to_ansi(std::string s)
	{
		BSTR    bstrWide;
		char*   pszAnsi;
		int     nLength;
		const char *pszCode = s.c_str();

		nLength = MultiByteToWideChar(CP_UTF8, 0, pszCode, strlen(pszCode) + 1, NULL, NULL);
		bstrWide = SysAllocStringLen(NULL, nLength);

		MultiByteToWideChar(CP_UTF8, 0, pszCode, strlen(pszCode) + 1, bstrWide, nLength);

		nLength = WideCharToMultiByte(CP_ACP, 0, bstrWide, -1, NULL, 0, NULL, NULL);
		pszAnsi = new char[nLength];

		WideCharToMultiByte(CP_ACP, 0, bstrWide, -1, pszAnsi, nLength, NULL, NULL);
		SysFreeString(bstrWide);

		std::string r(pszAnsi);
		delete[] pszAnsi;
		return r;
	}

	std::string utf16_to_utf8(std::wstring wstr)
	{
		std::string convertedString;
		int requiredSize = WideCharToMultiByte(CP_UTF8, 0, wstr.c_str(), wstr.length(), NULL, 0, NULL, NULL);
		if (requiredSize > 0)
		{
			convertedString.resize(requiredSize);
			WideCharToMultiByte(CP_UTF8, 0, wstr.c_str(), wstr.length(), &convertedString[0], requiredSize, NULL, NULL);
		}
		return convertedString;
	}

	std::wstring utf8_to_utf16(std::string str)
	{
		std::wstring convertedString;
		int requiredSize = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), str.length(), NULL, 0);
		if (requiredSize > 0)
		{
			convertedString.resize(requiredSize);
			MultiByteToWideChar(CP_UTF8, 0, str.c_str(), str.length(), &convertedString[0], requiredSize);
		}
		return convertedString;
	}

	std::string string_to_utf8(std::string str)
	{
		std::wstring w = utf8_to_utf16(str);
		return utf16_to_utf8(w);
	}
#endif
};

namespace utf8
{
#ifdef WIN32
	class ifstream : public std::ifstream, Windows_UTF_Converter
	{
	public:
		ifstream() : std::ifstream() {}

		explicit ifstream(const char* fileName, std::ios_base::open_mode mode = std::ios_base::in) :
			std::ifstream(utf8_to_utf16(fileName), mode)
		{
		}

		explicit ifstream(const std::string& fileName, std::ios_base::open_mode mode = std::ios_base::in) :
			std::ifstream(utf8_to_utf16(fileName), mode)
		{
		}

		void open(const char* fileName, std::ios_base::open_mode mode = std::ios_base::in)
		{
			std::ifstream::open(utf8_to_utf16(fileName), mode);
		}

		void open(const std::string& fileName, std::ios_base::open_mode mode = std::ios_base::in)
		{
			std::ifstream::open(utf8_to_utf16(fileName), mode);
		}
	};

	class ofstream : public std::ofstream, Windows_UTF_Converter
	{
	public:
		ofstream() : std::ofstream() {}

		explicit ofstream(const char* fileName, std::ios_base::open_mode mode = std::ios_base::out) :
			std::ofstream(utf8_to_utf16(fileName), mode)
		{
		}

		explicit ofstream(const std::string& fileName, std::ios_base::open_mode mode = std::ios_base::out) :
			std::ofstream(utf8_to_utf16(fileName), mode)
		{
		}

		void open(const char* fileName, std::ios_base::open_mode mode = std::ios_base::out)
		{
			std::ofstream::open(utf8_to_utf16(fileName), mode);
		}

		void open(const std::string& fileName, std::ios_base::open_mode mode = std::ios_base::out)
		{
			std::ofstream::open(utf8_to_utf16(fileName), mode);
		}
	};
#else
	typedef std::ifstream ifstream;
	typedef std::ofstream ofstream;
#endif
}