STDDEF(3)

🌸 NAME 🌸

okay so bestie, you're reading STDDEF(3) from the Library Functions Manual — the stddef page, aka standard type definitions. it's giving foundational header energy, and yes, we're gonna get through every single detail together. 💅✨

✨ SYNOPSIS ✨

#include <stddef.h>

that's the include. short, iconic, no notes. 🎀

💖 DESCRIPTION 💖

The <stddef.h> header defines the following types and macros, and you're gonna know all of them:

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. lowkey they get around. 🦋

🦋 SEE ALSO 🦋

go give these pages a lil read, bestie:

• 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 lesson but make it header lore. ⭐

🎀 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. literally ancient. 💀

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Mwah 💋 — this cutie comes from Debian, dated April 10, 2011, and it's the STDDEF(3) page. byeeee 🫶✨