Converting LPCSTR to LPCWSTR in C++, ATL not available

Before I start,

Please do understand that this question is not a duplicate. There are questions out there with the same header :

Convert LPCSTR to LPCWSTR

However, I did some research before asking this question and came across ATL or Active Template Library.

However the compiler I use, doesn't come with ATL, which does not allow me to convert from LPCSTR to LPCWSTR.

Also, to understand why I need to convert these two datatypes, the reason is that I am working on a project, which is actually a Console Game Engine.

In case you don't know, to rename a console window, you need to use SetConsoleTitle(LPCWSTR winName)

And at first, I used LPCWSTR datatype as an argument for my function. But, when I tried another function, which is actually a drawing function, this is what happens:

This combination of UNICODE characters that you see here, is a function for drawing a rectangle on the console. The rectangle correctly displays, however, there is some text, or should I say, the Console Title itself, displayed across the rectangle.

I did not add any such thing of displaying the console title on the rectangle, nor did I mess up my code in any way. I burned through my code a few times, and there was nothing wrong, however, somehow, the console title is displayed on the rectangle.

I somehow think that this is related to the LPCWSTR datatype, because when I tried the function, SetConsoleTitle() manually

Help me find a solution, will you?

Since the title is usually constant, you can simply call

SetConsoleTitle(L"My Title"); //or
const wchar_t* title = L"My Title";
SetConsoleTitle(title);

In general, use MultiByteToWideChar to convert ANSI or UTF8, to UTF16

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

std::wstring u16(const char* in, int codepage)
{
    if (!in) return std::wstring(L"");
    int size = MultiByteToWideChar(codepage, 0, in, -1, NULL, 0);
    std::wstring ws(size, L'\0');
    MultiByteToWideChar(codepage, 0, in, -1, ws.data(), size);
    return ws;
}

int main()
{
    const char* str = "My Title"; //<- ANSI string
    SetConsoleTitle(u16(str, CP_ACP).c_str());
    std::string s;
    std::cin >> s;

    str = reinterpret_cast<const char*>(u8"Ελληνικά"); //<- UTF8
    SetConsoleTitle(u16(str, CP_UTF8).c_str());
    std::cin >> s;

    return 0;
}

Note that the title changes back when program exits.