The header <cstddef> contains the same types and definitions as the standard C stddef.h with the following changes as shown in the following table.
| NULL | The macro NULL is an implementation-defined C++ constant value. EWL defines this as 0L. |
| offsetof | This macro accepts a restricted set of type arguments that shall be a POD structure or a POD union. The result of applying the offsetof macro to a field that is a static data member or a function member is undefined. |
| ptrdiff_t | No change from standard C. An signed integral type large enough to hold the difference between two pointers. |
| size_t | No change from standard C. An unsigned integral type large enough to hold the result of the sizeof operator. |