Converting a file from ANSI to utf8

ansi2utf8.cpp

// ansi2utf8.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>
#include <string>
#include <fstream>
#include <streambuf>

#include <atlcore.h>

#include <atlconv.h>

int wmain(int argc, wchar_t *argv[])
{
    if (argc != 3)
    {
        std::cerr << "Wrong parameters number.\n";
        return 1;
    }

    std::ifstream t(argv[1]);
    std::string str;

    t.seekg(0, std::ios::end);
    str.reserve(t.tellg());
    t.seekg(0, std::ios::beg);

    str.assign((std::istreambuf_iterator<char>(t)),
        std::istreambuf_iterator<char>());

    std::ofstream oft(argv[2]);

    const char tag[] = { char(0xEF), char(0xBB), char(0xBF) };
    oft << tag;

    oft << static_cast<const char*>(ATL::CW2A(ATL::CA2W(str.c_str(), CP_ACP), CP_UTF8));
}