Why does wxWidgets not leak Frames?

Question

I'm trying to learn wxWidgets, but I'm stuck on a point which I can't find an explanation for anywhere in the documentation. I am trying to understand this minimal wxWidgets program:

#include <wx/wx.h>

class MyApp : public wxApp
{
    virtual bool OnInit();
};

IMPLEMENT_APP(MyApp)

bool MyApp::OnInit()
{
    wxFrame *frame = new wxFrame(NULL, -1, _("Hello World"), wxPoint(50, 50),
                                  wxSize(450, 350));       
    frame->Show(true);
    return true;
}

Specifically, why is it that frame does not leak? When does it get released and whose responsibility is is? In a normal program a pointer that does not get passed to anything and that goes out of scope without being deleted is almost certainly a leak, but apparently this is not so in wxWidgets.

Answer 1

Cleanup is discussed here: http://docs.wxwidgets.org/2.9.2/overview_windowdeletion.html

Answer 2

See the note in the Hello World example on the wxWidgets wiki:

http://wiki.wxwidgets.org/Hello_World

"You could be wondering why the frame variable isn't deleted anywhere. By setting the frame as the top window of the application, the application will delete the frame for us (for a more in-depth explanation, see Avoiding Memory Leaks)."

However, the code you posted doesn't call SetTopWindow() the way the code from the wiki does. So I imagine it would leak.