The C <stddef.h> header defines several types and macros. Many of these definitions also appear in other header files. These types and macros are available to use in a current program after including the header file using - #include <stddef.h>. All types and macros of this header file are listed below:
| Types | Description |
|---|
| ptrdiff_t |
Signed integer type of the result of difference of two pointers. |
| size_t |
Unsigned integer type. |
| max_align_t (C11) |
Type with widest scalar alignment. |
| Function | Description |
|---|
| offsetof |
Return member offset. |
| Macros | Description |
|---|
| NULL |
Null pointer. |
