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Revision as of 18:27, 1 December 2013

<assert.h> C Header

Macros:

C Standard Library

C Standard Library

<assert.h>(C89) <complex.h>(C99)op <ctype.h>(C89) <errno.h>(C89) <fenv.h>(C99) <float.h>(C89) <inttypes.h>(C99) <iso646.h>(NA1) <limits.h>(C89) <locale.h>(C89) <math.h>(C89) <setjmp.h>(C89) <signal.h>(C89) <stdalign.h>(C11) <stdarg.h>(C89) <stdatomic.h>(C11)op <stdbool.h>(C99) <stddef.h>(C89) <stdint.h>(C99) <stdio.h>(C89) <stdlib.h>(C89) <stdnoreturn.h>(C11) <string.h>(C89) <tgmath.h>(C99) <threads.h>(C11)op <time.h>(C89) <uchar.h>(C11) <wchar.h>(NA1) <wctype.h>(NA1)

op - Optional Header v · d · e

v · d · e

The static_assert macro, which is part of <assert.h>, is a convenient object-like macro name that expands to the _Static_assert keyword.

I.E., 

#include <assert.h>
#define static_assert _Static_assert

Description

The static_assert object-like macro expands to the _Static_assert, a keyword added in C11 to provide compile-time assertion.

Example

#include <assert.h>

static_assert(sizeof(int) == 4, "Code relies on int being exactly 4 bytes");

int main(void)
{
    return 0;
}

On a machine where sizeof (int) is not 4, a constraint violation occurs. On such implementations, a diagnostic message is printed similar to the one below: 

example.c:3:1: error: static assertion failed "Code relies on int being exactly 4 bytes"
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