gl/minmax.h

   1 /* MIN, MAX macros.
   2    Copyright (C) 1995, 1998, 2001, 2003, 2005, 2009-2011 Free Software
   3    Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software Foundation,
  17    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  18
  19 #ifndef _MINMAX_H
  20 #define _MINMAX_H
  21
  22 /* Note: MIN, MAX are also defined in <sys/param.h> on some systems
  23    (glibc, IRIX, HP-UX, OSF/1).  Therefore you might get warnings about
  24    MIN, MAX macro redefinitions on some systems; the workaround is to
  25    #include this file as the last one among the #include list.  */
  26
  27 /* Before we define the following symbols we get the <limits.h> file
  28    since otherwise we get redefinitions on some systems if <limits.h> is
  29    included after this file.  Likewise for <sys/param.h>.
  30    If more than one of these system headers define MIN and MAX, pick just
  31    one of the headers (because the definitions most likely are the same).  */
  32 #if HAVE_MINMAX_IN_LIMITS_H
  33 # include <limits.h>
  34 #elif HAVE_MINMAX_IN_SYS_PARAM_H
  35 # include <sys/param.h>
  36 #endif
  37
  38 /* Note: MIN and MAX should be used with two arguments of the
  39    same type.  They might not return the minimum and maximum of their two
  40    arguments, if the arguments have different types or have unusual
  41    floating-point values.  For example, on a typical host with 32-bit 'int',
  42    64-bit 'long long', and 64-bit IEEE 754 'double' types:
  43
  44      MAX (-1, 2147483648) returns 4294967295.
  45      MAX (9007199254740992.0, 9007199254740993) returns 9007199254740992.0.
  46      MAX (NaN, 0.0) returns 0.0.
  47      MAX (+0.0, -0.0) returns -0.0.
  48
  49    and in each case the answer is in some sense bogus.  */
  50
  51 /* MAX(a,b) returns the maximum of A and B.  */
  52 #ifndef MAX
  53 # define MAX(a,b) ((a) > (b) ? (a) : (b))
  54 #endif
  55
  56 /* MIN(a,b) returns the minimum of A and B.  */
  57 #ifndef MIN
  58 # define MIN(a,b) ((a) < (b) ? (a) : (b))
  59 #endif
  60
  61 #endif /* _MINMAX_H */