7.2 Diagnostics <assert.h>

• 7.2.1 Program diagnostics
  • 7.2.1.1 The assert macro

1

The header <assert.h> defines the assert macro and refers to another macro,

NDEBUG

which is not defined by <assert.h>. If NDEBUG is defined as a macro name at the point in the source file where <assert.h> is included, the assert macro is defined simply as

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

The assert macro is redefined according to the current state of NDEBUG each time that <assert.h> is included.

2

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