MyDLLExports.cpp

#define __BUILDING_DLL
#include "MyDLLExports.h"
#include "windows.h"
#include <string>
#include <cwchar>

// appends "abcdef" to text in girdi.
// girdi must be user supplied buffer of at least 256 wchar_t.
// return value is girdi
wchar_t *__stdcall deneme(wchar_t *girdi)
{
    // No need to convert to single byte character strings.
    std::wstring ws(girdi);
    ws.append(L"abcdef");

    // Copy text in string to buffer provided by user.
    std::wcscpy_s(girdi, 256, ws.c_str());
    return girdi;

//---------------------------------------------------
//  alternatively, you could simply do:
//---------------------------------------------------
//  std::wscat_s(girdi, 256, L"abcdef");
//  return girdi;
//---------------------------------------------------
}