> main()
> {
>   graph_t g = fun_A();
>   fun_B(g);
> }


I tried as you suggested, and it does work in Release mode (Visual Studio
2005), but NOT in Debug mode. Very strange.
The CPU keeps running at the line
return myGraph;
and does not go further.  Any suggestions? Thanks!

Debug it and break the process while its "stuck". That should give you some idea why it may not be working. It sounds like it may be broken copy constructor or some place variable wasn't initialized correctly.

It's also hard to say without more context. You might try posting your code or something similar to it.
 
Andrew Sutton
andrew.n.sutton@gmail.com