stddef(3) [netbsd man page]

STDDEF(3)						   BSD Library Functions Manual 						 STDDEF(3)

NAME

     stddef -- standard type definitions

SYNOPSIS

     #include <stddef.h>

DESCRIPTION

     The <stddef.h> header defines the following types and macros:

	 1.   ptrdiff_t, a signed integer type of the result of subtracting two pointers;

	 2.   size_t, an unsigned integer type of the result of the sizeof() operator;

	 3.   wchar_t, an integer type whose range of values can represent distinct wide-character codes for all members of the largest character
	      set specified among the supported locales: the null character has the code value 0 and each member of the character set has a code
	      value equal to its value when used as the lone character in an integer character constant;

	 4.   NULL, which expands to an implementation-defined null pointer constant; and

	 5.   offsetof(), a macro that expands to an integer constant as described in offsetof(3).

     Some of the described types and macros may appear also in other headers.

SEE ALSO

     offsetof(3), stdlib(3), unistd(3)

STANDARDS

     As described here, the <stddef.h> header conforms to ISO/IEC 9899:1999 (``ISO C99'') and IEEE Std 1003.1-2001 (``POSIX.1'').  Some of the
     types and macros conform to earlier standards such as ANSI X3.159-1989 (``ANSI C89'').

HISTORY

     In the current form the <stddef.h> header was introduced in NetBSD 0.8, the first official release of NetBSD.  Some definitions such as NULL
     were first introduced already in the <nsys/param.h> header of Version 4 AT&T UNIX.

BSD
								  April 10, 2011							       BSD

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 con-
		    stant.

       size_t	    Unsigned integer type of the result of the sizeof operator.

       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)  util-
       ity.

ATTRIBUTES

       See attributes(5) 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(5), standards(5)

SunOS 5.11							    10 Sep 2004 						   stddef.h(3HEAD)