C / C++ / MFC

Code-o-mat wrote:

I could try creating a bitmap, drawing the lines onto it, trying to render an
alpha channel somehow and then alphablend this onto the original image but i
wouldn't like to do this because it sounds a lot like wasting resources and not
even sure how to render the alpha.

void CMFCApplicationView::OnSize(UINT nType, int cx, int cy)
{
    m_windowWrapper.OnSize(nType, cx, cy);
    CView::OnSize(nType, cx, cy);
}

void CMyWindowWrapper::OnSize(UINT nType, int cx, int cy)
{
    IntPtr^ hChildWnd = m_pMembers->m_myWindow->GetHwnd();
    ::SetWindowPos((HWND)hChildWnd->ToPointer(), 0, 0, 0, cx, cy, SWP_NOMOVE | SWP_ASYNCWINDOWPOS | SWP_NOZORDER);
}

Blah const& b const = GetMyBlah(); // const reference to a const Blah

void GetBlah2(Blah const * blah) { } // #1 method taking pointer to const Blah
void GetBlah2(Blah const * const blah) { } // #2 method taking const pointer to const Blah

const Blah* blah1 = new Blah(); // pointer to const Blah
Blah const * const blah2 = new Blah(); // const pointer to const Blah

void GetBlah2(Blah const *& blah) { } // #1 method taking pointer to const Blah
void GetBlah2(Blah const * const blah) { } // #2 method taking const pointer to const Blah

const Blah* GetBlah1(const Blah*& const b) {
   b = 0; // error: you cannot modify a const reference!
   return b;
}
const Blah* GetBlah2(const Blah*& b) {
   b = 0; // error: you cannot modify a reference, as it's always const!
   return b;
}
const Blah* GetBlah3(const Blah* const b) {
   b = 0; // error: you cannot modify a const pointer
   return b;
}
const Blah* GetBlah4(const Blah* b) {
   b = 0; // ok
   return b;
}
int main() {
   Blah* a = new Blah;
   Blah* b = GetBlah4(a); // this does not modify a
   assert(b==0);
   assert(a!=0);
   delete a;
   return 0;
}

Stefan_Lang wrote:

const Blah* GetBlah1(const Blah*& const b) {
   b = 0; // not an error: you're assigning a new pointer value to b which will survive once returning from the method
   return b;
}
const Blah* GetBlah2(const Blah*& b) {
   b = 0; // not an error: again you're merely assigning a new pointer to b which will survive once returning from the method
   return b;
}

Stefan_Lang wrote:

Blah* b = GetBlah4(a); // this does not modify a

const Blah* p = GetMyBlahPtr();
Blah const* p = GetMyBlahPtr();

Blah* const p = GetMyBlahPtr();

case WM_KEYDOWN:
    sprintf(szText, "repeat count = %d", lParam & 0xFF);
    MessageBox(NULL, szText, "Guess What?", MB_OK|MB_ICONQUESTION);
    return 1;

LRESULT SendMessage(

    HWND hWnd,	// handle of destination window
    UINT Msg,	// message to send
    WPARAM wParam,	// first message parameter
    LPARAM lParam 	// second message parameter
   );