WinRT(C++/CX) UTF8_To_Std_Str and UTF8_To_Managed_Str

UTF8_To_Std_Str_and_UTF8_To_Managed_Str.cpp

#include <string>
#include <Windows.h>

std::string UTF8_To_Std_Str(const std::string & str)
{
	int nwLen = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), -1, NULL, 0);

	wchar_t* pwBuf = new wchar_t[nwLen + 1];
	memset(pwBuf, 0, nwLen * 2 + 2);

	MultiByteToWideChar(CP_UTF8, 0, str.c_str(), str.length(), pwBuf, nwLen);

	int nLen = WideCharToMultiByte(CP_ACP, 0, pwBuf, -1, NULL, NULL, NULL, NULL);

	char* pBuf = new char[nLen + 1];
	memset(pBuf, 0, nLen + 1);

	WideCharToMultiByte(CP_ACP, 0, pwBuf, nwLen, pBuf, nLen, NULL, NULL);

	std::string retStr = pBuf;

	delete[] pBuf;
	delete[] pwBuf;

	pBuf = NULL;
	pwBuf = NULL;

	return retStr;
}

Platform::String^ UTF8_To_Managed_Str(const std::string & str)
{
	int nwLen = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), -1, NULL, 0);

	wchar_t* pwBuf = new wchar_t[nwLen + 1];
	memset(pwBuf, 0, nwLen * 2 + 2);

	MultiByteToWideChar(CP_UTF8, 0, str.c_str(), str.length(), pwBuf, nwLen);

	Platform::String^ pStr = ref new Platform::String(pwBuf);

	delete[] pwBuf;
	pwBuf = NULL;

	return pStr;
}

Platform::String^ UTF8_To_Managed_Str(const std::string & str)
{
	int size = MultiByteToWideChar(CP_UTF8, MB_COMPOSITE, str.c_str(), str.length(), nullptr, 0);
	std::wstring utf16_str(size, '\0');
	MultiByteToWideChar(CP_UTF8, MB_COMPOSITE, str.c_str(), str.length(), &utf16_str[0], size);
	
	Platform::String^ pStr = ref new Platform::String(utf16_str.c_str());
	
	return pStr;
}