Thread: How to set up libconv in visual c++

If you're not trying to write something portable, then you can use the following Windows specific code:

Code:

#include <windows.h>
#include <string>
#include <vector>

std::wstring str_to_wstr(const std::string &str, UINT cp = CP_ACP)
{
    int len = MultiByteToWideChar(cp, 0, str.c_str(), str.length(), 0, 0);
    if (!len)
        return L"ErrorA2W";

    std::vector<wchar_t> wbuff(len + 1);
    // NOTE: this does not NULL terminate the string in wbuff, but this is ok
    //       since it was zero-initialized in the vector constructor
    if (!MultiByteToWideChar(cp, 0, str.c_str(), str.length(), &wbuff[0], len))
        return L"ErrorA2W";

    return &wbuff[0];
}//str_to_wstr

std::string wstr_to_str(const std::wstring &wstr, UINT cp = CP_ACP)
{
    int len = WideCharToMultiByte(cp, 0, wstr.c_str(), wstr.length(), 
                                  0, 0, 0, 0);
    if (!len)
        return "ErrorW2A";

    std::vector<char> abuff(len + 1);

    // NOTE: this does not NULL terminate the string in abuff, but this is ok
    //       since it was zero-initialized in the vector constructor
    if (!WideCharToMultiByte(cp, 0, wstr.c_str(), wstr.length(), 
        &abuff[0], len, 0, 0))
    {
        return "ErrorW2A";
    }//if

    return &abuff[0];
}//wstr_to_str

Windows codepage 936 is for GBK, which is an extension of GB2312.

Code:

    string gbk;
    ...
    wstring utf16 = str_to_wstr(gbk, 936);
    string utf8 = wstr_to_str(utf16, CP_UTF8);

gg