Question

This function works perfectly fine, or so the compiler/debugger tells me

void GUIManager::init(ToScreen* tS)
{
    toScreen = tS;
    loadFonts();
    GUI_Surface = SDL_SetVideoMode( toScreen->width, toScreen->height, 32, SDL_SWSURFACE );
    components.push_back(&PlainText("Hello, World!", font, -20, -40));

}

In here, the first function call raises an access violation error.
The debugger doesn’t show any problems.
I don’t get the chance to debug components[0], since the program halts here.

void GUIManager::draw() 
{
    // This line here is the problem
    components[0].draw(GUI_Surface);
    // This line here is the problem


    SDL_BlitSurface(GUI_Surface, NULL, toScreen->Screen_Surface, NULL);
}

In case it’s needed, this is my ‘components’

boost::ptr_vector<GUIComponent> components;

Just let me know if any other code is needed. Perhaps that of PlainText, or GUIComponent

Answer 1

Instead of pushing pointer to temporary, which ends its lifetime just after this line:

components.push_back(&PlainText("Hello, World!", font, -20, -40));

You should push dynamic object, which will exist as long as components:

components.push_back(new PlainText("Hello, World!", font, -20, -40));

See doc: http://www.boost.org/doc/libs/1_51_0/libs/ptr_container/doc/ptr_sequence_adapter.html#modifiers

void push_back( T* x ); 
    Requirements: x != 0 
    Effects: Inserts the pointer into container and takes ownership of it
    Throws: bad_pointer if x == 0
    Exception safety: Strong guarantee