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)