@node ax_check_sign
@unnumberedsec ax_check_sign

@majorheading Synopsis

@smallexample
AX_CHECK_SIGN (TYPE, [ACTION-IF-SIGNED], [ACTION-IF-UNSIGNED], [INCLUDES])
@end smallexample

@majorheading Description

Checks whether TYPE is signed or not. If no INCLUDES are specified, the
default includes are used. If ACTION-IF-SIGNED is given, it is
additional shell code to execute when the type is signed. If
ACTION-IF-UNSIGNED is given, it is executed when the type is unsigned.

This macro assumes that the type exists. Therefore the existence of the
type should be checked before calling this macro. For example:

@smallexample
  AC_CHECK_HEADERS([wchar.h])
  AC_CHECK_TYPE([wchar_t],,[ AC_MSG_ERROR([Type wchar_t not found.]) ])
  AX_CHECK_SIGN([wchar_t],
    [ AC_DEFINE(WCHAR_T_SIGNED, 1, [Define if wchar_t is signed]) ],
    [ AC_DEFINE(WCHAR_T_UNSIGNED, 1, [Define if wchar_t is unsigned]) ], [
  #ifdef HAVE_WCHAR_H
  #include <wchar.h>
  #endif
  ])
@end smallexample

@majorheading Source Code

Download the
@uref{http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=blob_plain;f=m4/ax_check_sign.m4,latest
version of @file{ax_check_sign.m4}} or browse
@uref{http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=history;f=m4/ax_check_sign.m4,the
macro's revision history}.

@majorheading License

@w{Copyright @copyright{} 2008 Ville Laurikari @email{vl@@iki.fi}}

Copying and distribution of this file, with or without modification, are
permitted in any medium without royalty provided the copyright notice
and this notice are preserved. This file is offered as-is, without any
warranty.