STL list - Assertion Error :(

Hi ppl,

I am not very good with STL and I am getting an error in trying to delete the contents of an iterator and the iterator itself and then continue without them.
I am not sure how to overcome the error.

Any help would be greatly appreciated as to how this can be overcome.

Code:

  RECT          rcLastSpPos;
  SPRITEACTION  saSpriteAction;
  list<Sprite*>::iterator SpriteIterator;
  for (SpriteIterator = m_lSprites.begin(); SpriteIterator != m_lSprites.end(); SpriteIterator++)
  {
    rcLastSpPos = (*SpriteIterator)->GetPosition();

    // Update the sprite
    saSpriteAction = (*SpriteIterator)->Update();

    // Handle the SA_KILL sprite action
    if (saSpriteAction & SA_KILL)
    {
      // Destroy the sprite
      delete (*SpriteIterator);
      m_lSprites.erase(SpriteIterator);
      SpriteIterator--;
      continue;
    }
etc....etc...
    
  }

List iterator not incremental.... Assertion Error



Thanks

This sounds familiar, but anyway:

Code:

RECT          rcLastSpPos;
SPRITEACTION  saSpriteAction;
list<Sprite*>::iterator SpriteIterator = m_lSprites.begin();
while (SpriteIterator != m_lSprites.end())
{
    rcLastSpPos = (*SpriteIterator)->GetPosition();

    // Update the sprite
    saSpriteAction = (*SpriteIterator)->Update();

    // Handle the SA_KILL sprite action
    if (saSpriteAction & SA_KILL)
    {
        // Destroy the sprite
        delete *SpriteIterator;
        m_lSprites.erase(SpriteIterator++);
    }
    else
    {
        // etc....etc...
        ++SpriteIterator;
    }
}

The important part is about avoiding iterator invalidation by using post-increment.

Originally Posted by laserlight

The important part is about avoiding iterator invalidation by using post-increment.

Yes it does sound familiar, and again I don't understand why you're teaching people to use erase that way. It's very non-intuitive, and I doubt most people would understand why post-increment works and pre-increment doesn't. Then if someone else sees this person's code, they might not know that pre-inc wont also work.
I always recommend this:

Code:

       SpriteIterator = m_lSprites.erase(SpriteIterator);