assert.h(7POSIX)

📦 version 2017a, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu resolute, ubuntu stonking

💖 assert.h — bestie, let's verify that assertion 💖

okay so real talk, this one's from the POSIX Programmer's Manual — the 7POSIX girlies ✨

🌸 PROLOG 🌸

Heads up, queen: this manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ — so like, go consult the corresponding Linux manual page for the details on Linux behavior — or honestly the interface might just not be implemented on Linux at all 🙈. Either way, we move.

✨ NAME ✨

assert.h — verify program assertion 💅

🎀 SYNOPSIS 🎀

#include <assert.h>

that's it, that's the whole vibe 🦋

💜 DESCRIPTION 💜

So the functionality on this reference page? It's aligned with the ISO C standard — periodt. If there's any conflict between what's described here and the ISO C standard, that conflict is unintentional (nobody did that on purpose, bestie), and this volume of POSIX.1-2017 defers to the ISO C standard. The ISO C standard is the referee, no cap.

The <assert.h> header shall define the assert() macro. It refers to the macro NDEBUG which is not defined in the header. So if NDEBUG is defined as a macro name before the inclusion of this header, the assert() macro shall be defined simply as:

#define assert(ignore)((void) 0)

Otherwise — like, if NDEBUG isn't defined — the macro behaves as described in assert(). 👑

And the way that the assert() macro shall be redefined according to the current state of NDEBUG each time <assert.h> is included?? Obsessed. It re-vibes every single time. 🔥

Also super important: the assert() macro shall be implemented as a macro, not as a function. So if the macro definition is suppressed in order to access an actual function, the behavior is undefined 💀 — not a cute idea, don't do it.

The following sections are informative. 📝

🧚 APPLICATION USAGE 🧚

None. literally nothing, we're chillin' 🌸

🌈 RATIONALE 🌈

None. also nothing 🫶

⭐ FUTURE DIRECTIONS ⭐

None. nothing here either, iconic behavior honestly 💅

🦋 SEE ALSO 🦋

  • The System Interfaces volume of POSIX.1-2017, assert()

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

and that's the whole page bestie!! shoutout to IEEE/The Open Group, 2017 for bringing us assert.h(7POSIX) — mwah, go verify those assertions responsibly 💖✨🎀🦋
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