/*** Hook functions for memory allocation and disposal.** This makes it easy to substitute garbage collection systems** such as Boehm's GC by assigning these function pointers** to the GC's allocation routines. By default these point** to the ANSI standard malloc, realloc, free, etc.**** Users should call the normal objc routines above for** memory allocation and disposal within their programs.*/objc_EXPORTvoid*(*_objc_malloc)(size_t);objc_EXPORTvoid*(*_objc_atomic_malloc)(size_t);objc_EXPORTvoid*(*_objc_valloc)(size_t);objc_EXPORTvoid*(*_objc_realloc)(void*,size_t);objc_EXPORTvoid*(*_objc_calloc)(size_t,size_t);objc_EXPORTvoid(*_objc_free)(void*);