4.3BSD - /usr/include/assert.h

   1: /*	assert.h	4.2	85/01/21	*/
   2: 
   3: # ifndef NDEBUG
   4: # define _assert(ex)    {if (!(ex)){fprintf(stderr,"Assertion failed: file \"%s\", line %d\n", __FILE__, __LINE__);exit(1);}}
   5: # define assert(ex) _assert(ex)
   6: # else
   7: # define _assert(ex)
   8: # define assert(ex)
   9: # endif

Defined macros

Usage of this include