libstdc++-v3/testsuite/std/ranges/iota/iota_view.cc

   1 // Copyright (C) 2019-2022 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 <ranges>
  23 #include <testsuite_hooks.h>
  24
  25 void
  26 test01()
  27 {
  28   int vals[5] = { };
  29   int* out = vals;
  30   for (int i : std::ranges::iota_view{1, 4})
  31     *out++ = i;
  32   VERIFY(out == vals + 3);
  33   VERIFY(vals[0] == 1);
  34   VERIFY(vals[1] == 2);
  35   VERIFY(vals[2] == 3);
  36   VERIFY(vals[3] == 0);
  37 }
  38
  39 void
  40 test02()
  41 {
  42   auto v = std::ranges::views::iota(4);
  43   auto it = v.begin();
  44   VERIFY( *it == 4 );
  45   ++it;
  46   VERIFY( *it == 5 );
  47   it++;
  48   VERIFY( *it == 6 );
  49 }
  50
  51 void
  52 test03()
  53 {
  54   auto v = std::ranges::views::iota(10, 15);
  55   auto it = v.begin();
  56   VERIFY( *it == 10 );
  57   it += 2;
  58   VERIFY( *it == 12 );
  59   it += 2;
  60   VERIFY( *it == 14 );
  61   ++it;
  62   VERIFY( it == v.end() );
  63 }
  64
  65 void
  66 test04()
  67 {
  68   int x[] = {1,2,3};
  69   auto v = std::ranges::views::iota(std::counted_iterator(x, 3),
  70                                     std::default_sentinel);
  71   auto it = v.begin();
  72   VERIFY( (*it).base() == x );
  73   ++it;
  74   VERIFY( (*it).base() == x+1 );
  75   ++it;
  76   VERIFY( (*it).base() == x+2 );
  77   ++it;
  78   VERIFY( it == v.end() );
  79 }
  80
  81 // Verify we optimize away the 'bound' data member of an unbounded iota_view.
  82 static_assert(sizeof(std::ranges::iota_view<char>) == 1);
  83
  84 void
  85 test05()
  86 {
  87   // PR libstdc++/100690
  88   int x[] = {42, 42, 42};
  89   auto r = std::views::iota(std::ranges::begin(x), std::ranges::cbegin(x) + 3);
  90   VERIFY( r.end() - r.begin() == 3 );
  91   VERIFY( r.begin() - r.end() == -3 );
  92 }
  93
  94 void
  95 test06()
  96 {
  97   // Verify LWG 3523 changes.
  98   auto v1 = std::views::iota(0, 5);
  99   auto w1 = decltype(v1)(v1.begin(), v1.end());
 100   VERIFY( std::ranges::equal(v1, w1) );
 101
 102   auto v2 = std::views::iota(0);
 103   auto w2 = decltype(v2)(v2.begin(), v2.end());
 104   static_assert(std::same_as<decltype(w2.end()), std::unreachable_sentinel_t>);
 105   VERIFY( *w2.begin() == 0 );
 106
 107   auto v3 = std::views::iota(0, 5l);
 108   auto w3 = decltype(v3)(v3.begin(), v3.end());
 109   static_assert(!std::ranges::common_range<decltype(w3)>);
 110   VERIFY( std::ranges::equal(v3, w3) );
 111 }
 112
 113 int
 114 main()
 115 {
 116   test01();
 117   test02();
 118   test03();
 119   test04();
 120   test05();
 121   test06();
 122 }