xapian-core/common/exp10.h

   1 /** @file exp10.h
   2  * @brief Define exp10() if not provided by <cmath>
   3  */
   4 /* Copyright (C) 2017 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #ifndef XAPIAN_INCLUDED_EXP10_H
  22 #define XAPIAN_INCLUDED_EXP10_H
  23
  24 #ifndef PACKAGE
  25 # error config.h must be included first in each C++ source file
  26 #endif
  27
  28 #include <cmath>
  29 #if !HAVE_DECL_EXP10
  30 # if HAVE_DECL___EXP10
  31 inline double exp10(double x) { return __exp10(x); }
  32 # elif defined HAVE___BUILTIN_EXP10
  33 inline double exp10(double x) { return __builtin_exp10(x); }
  34 # else
  35 inline double exp10(double x) { return std::pow(10.0, x); }
  36 #endif
  37 #endif
  38
  39 #endif // XAPIAN_INCLUDED_EXP10_H