libstdc++-v3/testsuite/26_numerics/headers/cstdlib/dr2735.cc

   1 // Copyright (C) 2019-2020 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library 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 along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-do compile }
  19
  20 // NB: Don't include any other headers in this file.
  21 // LWG 2735. std::abs(short), std::abs(signed char) and others should return
  22 // int instead of double in order to be compatible with C++98 and C
  23 #include <cstdlib>
  24
  25 template<typename> struct is_int { };
  26 template<> struct is_int<int> { typedef int type; };
  27
  28 template<typename T>
  29 typename is_int<T>::type
  30 do_check(T t)
  31 {
  32   return T(0);
  33 }
  34
  35 template<typename T>
  36 void check()
  37 {
  38   do_check(std::abs(T(0)));
  39 }
  40
  41 void test()
  42 {
  43   check<short>();
  44   check<unsigned short>();
  45   check<char>();
  46   check<signed char>();
  47   check<unsigned char>();
  48 }