int stack_push( struct stack_state *ss, void *user_data );
struct stack_state *ss
- A stack state as allocated by stack_new.
- A void pointer of user data which will be pushed onto the stack.
The return value is 1 upon successful push, 0 upon failure. Failure occurs only when the stack has exhausted its freelist of elements. In this case, the user can call stack_guaranteed_push, which will allocate a new element and push using that. Remember however that the stack can never shrink, so any such call will permanently increase the size of the stack by one element.