assert

Remonter à Assert.h - Index

Header File

assert.h

Category

Diagnostic Routines

Prototype

void assert(int test);

Description

Tests a condition and possibly aborts.

assert is a macro that expands to an if statement; if test evaluates to zero, the assert macro calls the _assert function

void _RTLENTRY _EXPFUNC _assert(char * __cond, char * __file, int __line);

and aborts the program. The _assert function calls abort and asserts the following a message on stderr:

Assertion failed: test, file filename, line linenum

The filename and linenum listed in the message are the source file name and line number where the assert macro appears.

If you place the #define NDEBUG directive ("no debugging") in the source code before the #include <assert.h> directive, the macro expands to a no-op, the effect is to comment out the assert statement.

Return Value

None.

Example

  #include <assert.h>
  #include <stdio.h>
  #include <stdlib.h>
  struct ITEM {
     int key;
     int value;
  };
  /* add item to list, make sure list is not  null */
  void additem(struct ITEM *itemptr) {
     assert(itemptr != NULL);
     /* add item to list */
  }
  int main(void)
  {
     additem(NULL);
     return 0;
  }

Portability

POSIX	Win32	ANSI C	ANSI C++
+	+	+	+