LPCWSTR will not Cast Correctly on TextOut() Method

Question

Entire Code snippet...

#include <windows.h>
#include <string>
#include <vector>
using namespace std;
//=========================================================
// Globals.
HWND ghMainWnd = 0;
HINSTANCE ghAppInst = 0;
struct TextObj
{
    string s; // The string object.
    POINT p; // The position of the string, relative to the
    // upper-left corner of the client rectangle of
    // the window.
};
vector<TextObj> gTextObjs;

// Step 1: Define and implement the window procedure.
LRESULT CALLBACK
WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    // Objects for painting.
    HDC hdc = 0;
    PAINTSTRUCT ps;
    TextObj to;
    switch( msg )
    {
        // Handle left mouse button click message.
        case WM_LBUTTONDOWN:
            {
                to.s = "Hello, World.";
                // Point that was clicked is stored in the lParam.
                to.p.x = LOWORD(lParam);
                to.p.y = HIWORD(lParam);
                // Add to our global list of text objects.
                gTextObjs.push_back( to );
                InvalidateRect(hWnd, 0, false);
                return 0;
            }
        // Handle paint message.
        case WM_PAINT:
            {
                hdc = BeginPaint(hWnd, &ps);
                for(int i = 0; i < gTextObjs.size(); ++i)
                TextOut(hdc,
                        gTextObjs[i].p.x,
                        gTextObjs[i].p.y,
                        gTextObjs[i].s.c_str(),
                        gTextObjs[i].s.size());
                        EndPaint(hWnd, &ps);
                return 0;
            }
        // Handle key down message.
        case WM_KEYDOWN:
            {
                if( wParam == VK_ESCAPE )
                DestroyWindow(ghMainWnd);
                return 0;
                // Handle destroy window message.
                case WM_DESTROY:
                PostQuitMessage(0);
                return 0;
            }
    }
    // Forward any other messages we didn't handle to the
    // default window procedure.
    return DefWindowProc(hWnd, msg, wParam, lParam);
}

The problem is I am receiving an error from visual studio 2012 telling me that argument of type "const char*" is incompatible with parameter of type LPCWSTR. This occurs on this line of code:

hdc = BeginPaint(hWnd, &ps);
                for(int i = 0; i < gTextObjs.size(); ++i)
                TextOut(hdc,
                        gTextObjs[i].p.x,
                        gTextObjs[i].p.y,gTextObjs[i].s.c_str(), // <---happens here
                        gTextObjs[i].s.size());
                        EndPaint(hWnd, &ps);
                return 0;

I attempted a conversion ((LPCWSTR)gTextObjs[i].s.c_str()), but apparently this is VERY wrong based on research due to one byte per char array operation to two? Also received warning of "C4018: '<' : signed/unsigned mismatch" after this change. I am new to c++ and I'm pretty lost on this error considering the conversion is wrong.

I have reviewed some different threads in SO and nothing seems to tailor to this specific case (or I just don't quite understand the correlation between those threads and mine). :[

Also, just to clarify... the conversion "works", BUT it prints some weird Japanese/Chinese symbol looking writing and it's always different.

Answer 1

TextOut is resolving to TextOutW. That expects UTF-16 text. You pass 8 bit text. Either switch to UTF-16 held in wstring, or call TextOutA.