ASSERT(3alleg4)

💖 ASSERT 💖

bestie. okay so. this is the ASSERT page from the Allegro manual — a debugging helper macro to assert, straight out of the Allegro game programming library. 🎀

✨ SYNOPSIS ✨

#include <allegro.h>

void ASSERT(condition);

that's it. that's the whole vibe. two lines. iconic. 💅

🌸 DESCRIPTION 🌸

okay so here's the tea. ASSERT is a debugging helper macro. Normally? It literally compiles away to nothing. Like, poof, gone, no trace, zero cost. ✨

BUT — and this is the main character moment — if you defined the preprocessor symbol DEBUGMODE before including the Allegro headers, then it will actually do stuff: it checks the condition you handed it, and if that condition fails, it calls al_assert(). And al_assert()'s default action is to stop the program and report the assert. 😭 dramatic but necessary.

oh and a lil bonus fact: you can use this macro even when Allegro has not been initialised. No setup, no waiting, she's ready whenever. 🦋

Here's the example, verbatim, no cap:

#define DEBUGMODE
#include
...
void my_blitter(BITMAP *source, int flags)
{
   int some_variables;
   ASSERT(source != NULL);
   ASSERT(flags & GAME_RUNNING);
   ...
}

see how DEBUGMODE gets defined up top? that's the whole trick. then every ASSERT in your code actually gets to speak up instead of vanishing into the void. 🫶

⚠️ heads up bestie: leave DEBUGMODE undefined and your asserts just... don't exist. That's the design, not a bug. Know which mode you're in. 👑

🌈 SEE ALSO 🌈

• al_assert(3alleg4) — the function doing the actual work 💅
• TRACE(3alleg4) — sibling debugging energy
• register_assert_handler(3alleg4) — for when you want to control what happens when an assert fires 👑
• expackf(3alleg4) — yeah she's here too 🍓

and that's the page!! mwah. this was Allegro version 4.4.3, so keep that in mind if you're out here googling in the future. stay debugged, stay slayed, ily. 🧚💜