Question

I am working with an STL list and keep getting errors while attempting to retrieve the last element. I have a class

class Buffer {
private:
  list<Flit*> fifo;
  ...

public:
  ...
Flit *peek_last_flit(void) const;

  ...
};

and the implementation

Flit *Buffer::peek_last_flit(void) const {
   if (fifo.empty())
       return 0;

   Flit *f = *(fifo.begin());
   return f;
}

I have a similar implementation that returns the head of the list.

Flit *Buffer::peek_flit(void) const {
    if (fifo.empty())
        return 0;

    Flit *f = *(fifo.begin());
    return f;
}

How may I approach this issue(I am calling both procedures but when I call Peek_last_flit I get a debug asserion failure message:
Expression: list iterator not dereferencable.

How can I preserve iterators?
Any help would be much appreciated.

Answer 1

Flit *Buffer::peek_last_flit(void) const {
   if (fifo.empty())
       return 0;

   return fifo.back();
}