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      1 # ===========================================================================
      2 #        http://www.gnu.org/software/autoconf-archive/ax_cxx_bool.html
      3 # ===========================================================================
      4 #
      5 # SYNOPSIS
      6 #
      7 #   AX_CXX_BOOL
      8 #
      9 # DESCRIPTION
     10 #
     11 #   If the compiler recognizes bool as a separate built-in type, define
     12 #   HAVE_BOOL. Note that a typedef is not a separate type since you cannot
     13 #   overload a function such that it accepts either the basic type or the
     14 #   typedef.
     15 #
     16 # LICENSE
     17 #
     18 #   Copyright (c) 2008 Todd Veldhuizen
     19 #   Copyright (c) 2008 Luc Maisonobe <luc (a] spaceroots.org>
     20 #
     21 #   Copying and distribution of this file, with or without modification, are
     22 #   permitted in any medium without royalty provided the copyright notice
     23 #   and this notice are preserved. This file is offered as-is, without any
     24 #   warranty.
     25 
     26 #serial 7
     27 
     28 AU_ALIAS([AC_CXX_BOOL], [AX_CXX_BOOL])
     29 AC_DEFUN([AX_CXX_BOOL],
     30 [dnl
     31  AC_CACHE_CHECK(whether the compiler recognizes bool as a built-in type,
     32    ax_cv_cxx_bool,
     33    [dnl
     34      AC_LANG_PUSH([C++])
     35      AC_COMPILE_IFELSE([dnl
     36        AC_LANG_PROGRAM([int f(int  x){return 1;}
     37                         int f(char x){return 1;}
     38                         int f(bool x){return 1;}],
     39                        [bool b = true; return f(b);])],
     40        ax_cv_cxx_bool=yes, ax_cv_cxx_bool=no)
     41      AC_LANG_POP([C++])
     42   ])
     43   AS_IF([test "X$ax_cv_cxx_bool" = Xyes],
     44         [AC_DEFINE(HAVE_BOOL,,[define if bool is a built-in type])])
     45 ])
     46