NAME

assert.h - verify program assertion

SYNOPSIS

#include <assert.h>

DESCRIPTION

^[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2017 defers to the ISO C standard.

The <assert.h> header shall define the assert() macro. It refers to the macro NDEBUG which is not defined in the header. 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, the macro behaves as described in assert().

The assert() macro shall be redefined according to the current state of NDEBUG each time <assert.h> is included.

The assert() macro shall be implemented as a macro, not as a function. If the macro definition is suppressed in order to access an actual function, the behavior is undefined.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

XSH assert

CHANGE HISTORY

First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 6

The definition of the assert() macro is changed for alignment with the ISO/IEC 9899:1999 standard.