`<cstddef>`

Include the standard header <cstddef> to define the macros traditionally defined in the Standard C library header <stddef.h>. Including this header also ensures that the names declared with external linkage in the Standard C library header are declared in the std namespace. In this implementation, the names may or may not also be declared in the global namespace, depending on the specific translation environment.

#if <TRADITIONAL C HEADERS>
    #include <stddef.h>
#endif

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