Question

Before boost::shared_ptr, was it considered a bad practice to return a heap allocated pointer from a function, since the caller will be required to remember to free() that object?

Or, was it considered “normal”?

Answer 1

I don’t consider it bad practice, so long as your API also provides an equivalent XXX_free (or XXX_close, XXX_clearup, or whatever) function, that the client code can call when finished with the pointer.

That way, you have a consistent, symmetrical API, in the sense that responsibility for the lifetime of a heap object is maintained in one place.

This approach is also amenable to more-complex resource freeing. For example, if the pointer that gets returned is to a dynamically-allocated struct that in turn has members that point to dynamically-allocated memory, the entire cleanup procedure can be hidden/abstracted from the client code.