lib/minmax.h

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