SFML wczytywanie polskich znaków z pliku

std::wstring str = L"";
std::wifstream infile;
infile.open( path.c_str() ); // open file
if( infile ) {
    std::wstring s = L"";
    while( getline( infile, s ) ) {
        str += s;
        str += L"\n";
    }
}
//std::wcout << str << "\n";
txtInput = new TextInput( 100, 100, 500, 500, sf::Text( str, sty->font, 10 ) ); //sty-> font to czcionka

std::wstring multiByteToWideString( const char * szSrc )
{
    unsigned int iSizeOfStr = MultiByteToWideChar( CP_ACP, 0, szSrc, - 1, NULL, 0 );
    wchar_t * wszTgt = new wchar_t[ iSizeOfStr ];
    if( !wszTgt ) assert( 0 );
   
    MultiByteToWideChar( CP_ACP, 0, szSrc, - 1, wszTgt, iSizeOfStr );
    std::wstring wstr( wszTgt );
    delete( wszTgt );
    return( wstr );
}

std::string wideStringToMultiByte( const wchar_t * wszSrc )
{
    int iSizeOfStr = WideCharToMultiByte( CP_ACP, 0, wszSrc, - 1, NULL, 0, NULL, NULL );
    char * szTgt = new char[ iSizeOfStr ];
    if( !szTgt ) return( NULL );
   
    WideCharToMultiByte( CP_ACP, 0, wszSrc, - 1, szTgt, iSizeOfStr, NULL, NULL );
    std::string str( szTgt );
    delete( szTgt );
    return( str );
}

//i dalej:
txtInput = new TextInput( 100, 100, 500, 500, sf::Text( multiByteToWideString( str.c_str() ), sty->font, 10 ) );