libstdc++-v3/testsuite/26_numerics/midpoint/floating.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-options "-std=gnu++2a" }
  19 // { dg-do run { target c++2a } }
  20
  21 #include <numeric>
  22 #include <limits>
  23 #include <cfloat>
  24 #include <testsuite_hooks.h>
  25
  26 void
  27 test01()
  28 {
  29   using lim = std::numeric_limits<double>;
  30
  31   VERIFY( std::midpoint(2.0, 4.0) == 3.0 );
  32   VERIFY( std::midpoint(0.0, 0.4) == 0.2 );
  33   VERIFY( std::midpoint(0.0, -0.0) == 0.0 );
  34   VERIFY( std::midpoint(9e9, -9e9) == 0.0 );
  35
  36   VERIFY( std::midpoint(lim::max(), lim::max()) == lim::max() );
  37 }
  38
  39 void
  40 test02()
  41 {
  42   using lim = std::numeric_limits<float>;
  43
  44   VERIFY( std::midpoint(2.0f, 4.0f) == 3.0f );
  45   VERIFY( std::midpoint(0.0f, 0.4f) == 0.2f );
  46   VERIFY( std::midpoint(0.0f, -0.0f) == 0.0f );
  47   VERIFY( std::midpoint(9e9f, -9e9f) == 0.0f );
  48 }
  49
  50 void
  51 test03()
  52 {
  53   using lim = std::numeric_limits<long double>;
  54
  55   VERIFY( std::midpoint(2.0l, 4.0l) == 3.0l );
  56   VERIFY( std::midpoint(0.0l, 0.4l) == 0.2l );
  57   VERIFY( std::midpoint(0.0l, -0.0l) == 0.0l );
  58   VERIFY( std::midpoint(9e9l, -9e9l) == 0.0l );
  59 }
  60
  61 namespace test04
  62 {
  63   // https://gcc.gnu.org/ml/libstdc++/2019-03/msg00065.html
  64   constexpr double d = DBL_MIN + DBL_TRUE_MIN;
  65   static_assert( std::midpoint(d, d) == d );
  66
  67   constexpr float f = FLT_MIN + FLT_TRUE_MIN;
  68   static_assert( std::midpoint(f, f) == f );
  69
  70   constexpr long double l = LDBL_MIN + LDBL_TRUE_MIN;
  71   static_assert( std::midpoint(l, l) == l );
  72 }
  73
  74 int main()
  75 {
  76   test01();
  77   test02();
  78   test03();
  79 }