libstdc++-v3/testsuite/25_algorithms/for_each/constexpr.cc

   1 // Copyright (C) 2019-2025 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 { target c++20 } }
  19
  20 #include <algorithm>
  21 #include <array>
  22
  23 constexpr std::array<int, 12> ca0{{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}};
  24
  25 constexpr bool
  26 test()
  27 {
  28   int tot = 0;
  29   auto sum = [&total = tot](int i){ total += i; };
  30   auto sum2 = std::for_each(ca0.begin(), ca0.end(), sum);
  31
  32   return tot == 66;
  33 }
  34
  35 static_assert(test());
  36
  37 constexpr bool
  38 test_n()
  39 {
  40   int tot = 0;
  41   auto sum = [&total = tot](int i){ total += i; };
  42   auto sum2 = std::for_each_n(ca0.begin(), std::size(ca0)-1, sum);
  43
  44   return tot == 55;
  45 }
  46
  47 static_assert(test_n());