CTASSERT - reference manual online

CTASSERT(9)                       BSD Kernel Developer's Manual                       CTASSERT(9)

NAME
     CTASSERT — compile time assertion macro

SYNOPSIS
     #include <sys/param.h>
     #include <sys/systm.h>

     CTASSERT(expression);

DESCRIPTION
     The CTASSERT() macro evaluates expression at compile time and causes a compiler error if it
     is false.

     The CTASSERT() macro is useful for asserting the size or alignment of important data struc‐
     tures and variables during compilation, which would otherwise cause the code to fail at run
     time.

IMPLEMENTATION NOTES
     The CTASSERT() macro should not be used in a header file.  It is implemented using a dummy
     typedef, with a name (based on line number) that may conflict with a CTASSERT() in a source
     file including that header.

EXAMPLES
     Assert that the size of the uuid structure is 16 bytes.

           CTASSERT(sizeof(struct uuid) == 16);

SEE ALSO
     KASSERT(9)

AUTHORS
     This manual page was written by Hiten M. Pandya ⟨@FreeBSD.org⟩.

BSD                                     September 5, 2008                                     BSD