libstdc++-v3/testsuite/25_algorithms/max/constrained.cc

   1 // Copyright (C) 2020-2025 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 run { target c++20 } }
  19
  20 #include <algorithm>
  21 #include <functional>
  22 #include <testsuite_hooks.h>
  23 #include <testsuite_iterators.h>
  24
  25 using __gnu_test::test_container;
  26 using __gnu_test::test_range;
  27 using __gnu_test::input_iterator_wrapper;
  28
  29 namespace ranges = std::ranges;
  30
  31 struct X
  32 {
  33   int i, j;
  34 };
  35
  36 void
  37 test01()
  38 {
  39   VERIFY( ranges::max(1, 2) == 2);
  40   VERIFY( ranges::max(2, 1) == 2);
  41   VERIFY( ranges::max(1, 2, ranges::greater{}) == 1);
  42   VERIFY( ranges::max(1, 2, ranges::greater{}, std::negate<>{}) == 2);
  43   VERIFY( ranges::max(1, 2, {}, std::negate<>{}) == 1);
  44   VERIFY( ranges::max(X{1,2}, X{1,3}, {}, &X::i).j == 2 );
  45 }
  46
  47 void
  48 test02()
  49 {
  50   int x[] = {1,2,3,4};
  51   do
  52     {
  53       test_range<int, input_iterator_wrapper> cx(x);
  54       VERIFY( ranges::max(cx) == 4 );
  55       cx.bounds.first = x;
  56       VERIFY( ranges::max(cx, ranges::greater{}) == 1 );
  57       cx.bounds.first = x;
  58       VERIFY( ranges::max(cx, {}, std::negate<>{}) == 1);
  59       cx.bounds.first = x;
  60       VERIFY( ranges::max(cx, ranges::greater{}, std::negate<>{}) == 4 );
  61     } while (ranges::next_permutation(x).found);
  62
  63   constexpr X y[] = {{0,5},{1,2},{1,3}};
  64   static_assert(ranges::max(y, {}, &X::i).j == 2);
  65 }
  66
  67 void
  68 test03()
  69 {
  70   VERIFY( ranges::max({2,3,1,4}) == 4 );
  71   VERIFY( ranges::max({2,3,1,4}, ranges::greater{}) == 1 );
  72   VERIFY( ranges::max({2,3,1,4}, {}, std::negate<>{}) == 1 );
  73   VERIFY( ranges::max({2,3,1,4}, ranges::greater{}, std::negate<>{}) == 4 );
  74 }
  75
  76 void
  77 test04()
  78 {
  79   // PR libstdc++/112349 - ranges::max/min make unnecessary copies
  80   static int copies, moves;
  81   struct A {
  82     A(int m) : m(m) { }
  83     A(const A& other) : m(other.m) { ++copies; }
  84     A(A&& other) : m(other.m) { ++moves; }
  85     A& operator=(const A& other) { m = other.m; ++copies; return *this; }
  86     A& operator=(A&& other) { m = other.m; ++moves; return *this; }
  87     int m;
  88   };
  89   A r[5] = {5, 4, 3, 2, 1};
  90   ranges::max(r, ranges::less{}, &A::m);
  91   VERIFY( copies == 1 );
  92   VERIFY( moves == 0 );
  93   copies = moves = 0;
  94   A s[5] = {1, 2, 3, 4, 5};
  95   ranges::max(s, ranges::less{}, &A::m);
  96   VERIFY( copies == 5 );
  97   VERIFY( moves == 0 );
  98 }
  99
 100 int
 101 main()
 102 {
 103   test01();
 104   test02();
 105   test03();
 106   test04();
 107 }