stddef.h - standard type definitions
[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 defers to the ISO C standard.
The <stddef.h> header shall define the following macros:
- 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 shall define the following types:
- Signed integer type of the result of subtracting two pointers.
- 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.
- Unsigned integer type of the result of the sizeof operator.
The implementation shall support 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() function or the getconf utility.
<wchar.h> , <sys/types.h> , the System Interfaces volume of IEEE Std 1003.1-2001, confstr(), the Shell and Utilities volume of IEEE Std 1003.1-2001, getconf
First released in Issue 4. Derived from the ANSI C standard.