---
name: "ASSERT"
section: "3alleg4"
platform: "linux"
package: "allegro4-doc"
version: "2:4.4.3.1-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/ASSERT/3alleg4"
---

# ASSERT(3alleg4)

Debugging helper macro to assert. Allegro game programming library.

## NAME

ASSERT - Debugging helper macro to assert. Allegro game programming library.

## SYNOPSIS

**#include \<allegro.h\>**

**void ASSERT(condition);**

## DESCRIPTION

Debugging helper macro. Normally compiles away to nothing, but if you  defined the preprocessor symbol DEBUGMODE before including Allegro headers, it will check the supplied condition and call al\_assert() if it fails, whose default action is to stop the program and report the assert. You can use this macro even when Allegro has not been initialised. Example:

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

## SEE ALSO

**al\_assert**(3alleg4), **TRACE**(3alleg4), **register\_assert\_handler**(3alleg4), **expackf**(3alleg4)