libstdc++-v3/testsuite/std/ranges/adaptors/all.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 <ranges>
  23 #include <testsuite_hooks.h>
  24 #include <testsuite_iterators.h>
  25
  26 namespace ranges = std::ranges;
  27 namespace views = std::ranges::views;
  28
  29 void
  30 test01()
  31 {
  32   int x[] = {1,2,3,4,5};
  33   auto v = views::all(x);
  34
  35   static_assert(ranges::view<decltype(v)>);
  36   static_assert(ranges::random_access_range<decltype(v)>);
  37
  38   VERIFY( ranges::size(v) == 5 );
  39   VERIFY( ranges::size(x | views::all) == 5 );
  40   VERIFY( ranges::size(v | views::all | views::all) == 5 );
  41   VERIFY( ranges::size(v | (views::all | views::all)) == 5 );
  42
  43   ranges::reverse(v);
  44   VERIFY( ranges::equal(v, (int[]){5,4,3,2,1}) );
  45 }
  46
  47 void
  48 test02()
  49 {
  50   int x[5] = { 0 };
  51   int k = 0;
  52   for (auto&& i : ranges::ref_view{x})
  53     i += ++k;
  54   VERIFY( ranges::equal(x, (int[]){1,2,3,4,5}) );
  55 }
  56
  57 constexpr bool
  58 test03()
  59 {
  60   std::array ints{0,1,2,3,4,5};
  61   auto even = [] (int i) { return i%2==0; };
  62   auto odd = [] (int i) { return i%2==1; };
  63   auto square = [] (int i) { return i*i; };
  64   int sum = 0;
  65   for (auto v : (ints
  66                  | (views::all
  67                     | (views::filter(even)
  68                     | (views::filter(odd) | views::all)))
  69                  | views::transform(square)))
  70     sum += v;
  71   return sum == 0;
  72 }
  73
  74 constexpr bool
  75 test04()
  76 {
  77   auto odd = [] (int i) { return i%2==1; };
  78   auto square = [] (int i) { return i*i; };
  79   auto increment = [] (int i) { return i+1; };
  80   auto small = [] (int i) { return i<30; };
  81   auto non_negative = [] (int i) { return i>=0; };
  82   auto negative = [] (int i) { return i<0; };
  83   return ranges::equal(views::iota(-5)
  84                        | views::drop_while(negative)
  85                        | views::take_while(non_negative)
  86                        | views::transform(increment)
  87                        | views::filter(odd)
  88                        | views::take(3)
  89                        | views::all
  90                        | views::transform(square),
  91                        views::iota(-5)
  92                        | views::drop_while(negative)
  93                        | views::drop(1)
  94                        | views::filter(odd)
  95                        | views::transform(square)
  96                        | views::take_while(small)
  97                        | views::take_while(small));
  98 }
  99
 100 static_assert(std::is_empty_v<decltype(views::common
 101                                        | views::join
 102                                        | views::all
 103                                        | views::common
 104                                        | views::keys
 105                                        | views::reverse)>);
 106 static_assert(sizeof(decltype(views::take(5) | views::drop(5)))
 107               == sizeof(decltype(views::take(5)
 108                                  | views::join
 109                                  | views::common
 110                                  | views::all
 111                                  | views::keys
 112                                  | views::drop(5)
 113                                  | views::reverse)));
 114
 115 int
 116 main()
 117 {
 118   test01();
 119   test02();
 120   static_assert(test03());
 121   static_assert(test04());
 122 }