C# String std::string

string.cpp

using System;

#define s2S(s) gcnew String(s.c_str())

//REF: https://msdn.microsoft.com/en-us/library/1b4az623.aspx
string S2s(String ^s) {
	using namespace Runtime::InteropServices;
	const char* chars =
		(const char*)(Marshal::StringToHGlobalAnsi(s)).ToPointer();
	string ret = chars;
	Marshal::FreeHGlobal(IntPtr((void*)chars));
	return ret;
}

wstring S2ws(String ^s) {
	using namespace Runtime::InteropServices;
	const wchar_t* chars =
		(const wchar_t*)(Marshal::StringToHGlobalUni(s)).ToPointer();
	wstring ret = chars;
	Marshal::FreeHGlobal(IntPtr((void*)chars));
	return ret;
}