Wrapper Functions

To allocate an object at runtime, you use wrapper functions. Wrapper functions are implemented in C and perform a C++-to-C conversion. The allocation routines return a pointer to the base class object that indicates to the C++ compiler what is returned, but not the definitions. As in typical C, you can reference symbols in a sharable library because the functions are defined as extern C {}().

These functions are written in C++ and call new()() (or its equivalent alternative). Since the shareable object code has all of the header information from the base class, the derivative is constructed properly and has the same structure as statically-linked code.