Question

what is alloc.h? some questions on SO like this and this have included alloc.h.

but, when i tried to include it gcc gives error as error: alloc.h: No such file or directory

Has such file ever existed or those questions have included it just by mistake?

Answer 1

It’s a header file that declares memory-management functions like malloc, free, realloc.

That header file is deprecated.

For C use

#include <stdlib.h>

For C++ use

#include <memory>