STDDEF.H(3HEAD) Headers 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 character 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
operator.


max_align_t
A type that represents the maximum alignment supported
by the platform. The type may or may not be an integer
type, it may or may not be signed, no assumptions should
be made, other than that it has the maximum fundamental
alignment of the platform.


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(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+

SEE ALSO

getconf(1), confstr(3C), types.h(3HEAD), wchar.h(3HEAD),
attributes(7), standards(7)

January 14, 2015 STDDEF.H(3HEAD)