kc3-lang/gnulib/doc/posix-headers/assert.texi

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• Hash : c504bec0
  Author :
  Date : 2022-09-13T17:29:35
  

  assert-h: static_assert is a keyword in C23
  
  * m4/assert_h.m4 (gl_ASSERT_H): Also test for static_assert
  keyword a la C23, and define HAVE_C_STATIC_ASSERT if so.
  If not, arrange for config.h to #define static_assert
  by including <assert.h>, and then do "#undef assert"
  so that the assert macro still needs an explicit include.
  This should be safe even on very old hosts, as assert.h
  has been re-includable for decades.
  * tests/tests-assert.c: New test.
  * modules/assert-h-tests (Files, Makefile.am): Add it.
  

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• doc/posix-headers/assert.texi

• @node assert.h
  @section @file{assert.h}
  
  POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/assert.h.html}
  
  Gnulib module: assert-h
  
  See also the Gnulib modules @code{assert} and @code{verify}.
  
  Portability problems fixed by Gnulib:
  @itemize
  @item
  On older C platforms @code{<assert.h>} must be included before using
  @code{static_assert}.  For example, GCC versions before 13 do not
  support the @code{static_assert} keyword that was standardized by C23.
  @item
  On older platforms @code{static_assert} does not allow the second
  string-literal argument to be omitted.  For example, GCC versions
  before 9.1 do not support the single-argument @code{static_assert}
  that was standardized by C23 and C++17.
  @item
  Even-older platforms do not support @code{static_assert} at all.
  For example, GCC versions before 4.6 and G++ versions before 4.3
  do not support the two-argument form, which was standardized
  by C11 and C++11.
  @item
  Older C platforms might not support the obsolescent
  @code{_Static_assert} keyword or macro.
  This portability problem should not matter with code using this
  module, as such code should use @code{static_assert} instead.
  @end itemize
  
  Portability problems not fixed by Gnulib:
  @itemize
  @item
  A @code{static_assert} can also
  be used within a @code{struct} or @code{union} specifier, in place of
  an ordinary declaration of a member of the struct or union.  The
  Gnulib substitute can be used only as an ordinary declaration
  in code intended to be portable to C99 or earlier.
  @item
  In C23 and C++11 and later, @code{static_assert} is a keyword.
  In C11 and C17 it is a macro.  Any Gnulib substitute is also a macro.
  @item
  In C99 and later, @code{assert} can be applied to any scalar expression.
  In C89, the argument to @code{assert} is of type @code{int}.
  @end itemize
  

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