Standard library header <stddef.h>
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C
Concurrency support (C11)
Standard Library headers
<stdalign.h> (C11*)
<stdbit.h> (C23)
<stdbool.h> (C99*)
<stdckdint.h> (C23)
<stddef.h>
<stdint.h> (C99)
<stdmchar.h> (C29)
<stdnoreturn.h> (C11*)
<tgmath.h> (C99)
<threads.h> (C11)
<uchar.h> (C11)
<wchar.h> (C95)
<wctype.h> (C95)
This header is part of types support library, in particular, it provides additional basic types and convenience macros.
Contents
Types
Constants
Macros
[edit] Synopsis
#define __STDC_VERSION_STDDEF_H__ 202311L typedef /* see description */ ptrdiff_t ; typedef /* see description */ nullptr_t ; typedef /* see description */ max_align_t ; typedef /* see description */ wchar_t; typedef /* see description */ size_t ; #define NULL /* see description */ #define unreachable() /* see description */ #define offsetof(P, D) /* see description */
Only if the implementation defines __STDC_LIB_EXT1__ and additionally the user code
defines __STDC_WANT_LIB_EXT1__ before any inclusion of <stddef.h>:
#if defined(__STDC_WANT_LIB_EXT1__) typedef /* see description */ rsize_t; #endif