#include <bits/c++config.h>
#include <stddef.h>

Detailed Description

This is a Standard C++ Library file. You should #include this file in your programs, rather than any of the *.h implementation files.

This is the C++ version of the Standard C Library header stddef.h, and its contents are (mostly) the same as that header, but are all contained in the namespace std (except for names which are defined as macros in C).