STDDEF.H(3HEAD)STDDEF.H(3HEAD)NAME
stddef.h, stddef - standard type definitions
SYNOPSIS
#include <stddef.h>
DESCRIPTION
The <stddef.h> header defines the following macros:
NULL
Null pointer constant.
offsetof(type, member-designator)
Integer constant expression of type size_t, the value of which is
the offset in bytes to the structure member (member-designator),
from the beginning of its structure (type).
The <stddef.h> header defines the following types:
ptrdiff_t
Signed integer type of the result of subtracting two
pointers.
wchar_t
Integer type whose range of values can represent distinct
wide-character codes for all members of the largest char‐
acter set specified among the locales supported by the
compilation environment: the null character has the code
value 0 and each member of the portable character set has
a code value equal to its value when used as the lone
character in an integer character constant.
size_t
Unsigned integer type of the result of the sizeof opera‐
tor.
The implementation supports one or more programming environments in
which the widths of ptrdiff_t, size_t, and wchar_t are no greater than
the width of type long. The names of these programming environments can
be obtained using the confstr(3C) function or the getconf(1) utility.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌────────────────────┬─────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│Interface Stability │ Standard │
└────────────────────┴─────────────────┘
SEE ALSOgetconf(1), confstr(3C), types.h(3HEAD), wchar.h(3HEAD), attributes(5),
standards(5)
Sep 10, 2004 STDDEF.H(3HEAD)
