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

   1 // Copyright (C) 2020-2021 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 <algorithm>
  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 using __gnu_test::output_iterator_wrapper;
  29 using __gnu_test::forward_iterator_wrapper;
  30
  31 namespace ranges = std::ranges;
  32
  33 void
  34 test01()
  35 {
  36   const int c[6] = { 1, 2, 3, 4, 5, 6 };
  37
  38     {
  39       int x[6] = { 7, 8, 9, 4, 5, 6 };
  40       int a = 1;
  41       VERIFY( ranges::generate_n(x, 3, [&] { return a++; }) == x+3 );
  42       VERIFY( ranges::equal(x, c) );
  43     }
  44
  45     {
  46       int x[6] = { 7, 8, 9, 4, 5, 6 };
  47       int a = 1;
  48       test_container<int, forward_iterator_wrapper> cx(x);
  49       VERIFY( *ranges::generate_n(cx.begin(), 3, [&] { return a++; })
  50                == 4 );
  51       VERIFY( ranges::equal(cx, c) );
  52     }
  53
  54     {
  55       int x[6] = { 7, 8, 9, 4, 5, 6 };
  56       int a = 1;
  57       test_range<int, output_iterator_wrapper> rx(x);
  58       ranges::generate_n(ranges::begin(rx), 3, [&] { return a++; });
  59       VERIFY( ranges::equal(x, c) );
  60     }
  61 }
  62
  63 constexpr bool
  64 test02()
  65 {
  66   bool ok = true;
  67   int c[6] = { 1, 2, 3, 4, 5, 6 };
  68   int x[6];
  69   int a = 1;
  70   ranges::generate_n(x, 6, [&] { return a++; });
  71   ok &= ranges::equal(x, c);
  72   ranges::generate_n(c, 0, [] { return -1; });
  73   ok &= ranges::equal(x, c);
  74   ranges::generate_n(c, -2, [] { return -1; });
  75   ok &= ranges::equal(x, c);
  76   return ok;
  77 }
  78
  79 int
  80 main()
  81 {
  82   test01();
  83   static_assert(test02());
  84 }