libcxx/test/std/algorithms/ranges_robust_against_proxy_iterators.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: c++03, c++11, c++14, c++17
  10
  11 // <algorithm>
  12 //
  13 // Range algorithms should work with proxy iterators. For example, the implementations should use `iter_swap` (which is
  14 // a customization point) rather than plain `swap` (which might not work with certain valid iterators).
  15
  16 #include <algorithm>
  17
  18 #include <array>
  19 #include <concepts>
  20 #include <initializer_list>
  21 #include <iterator>
  22 #include <memory>
  23 #include <random>
  24 #include <ranges>
  25
  26 #include "MoveOnly.h"
  27 #include "test_iterators.h"
  28
  29 // (in, ...)
  30 template <class Func, std::ranges::range Input, class ...Args>
  31 constexpr void test(Func&& func, Input& in, Args&& ...args) {
  32   (void)func(in.begin(), in.end(), std::forward<Args>(args)...);
  33   (void)func(in, std::forward<Args>(args)...);
  34 }
  35
  36 // (in1, in2, ...)
  37 template <class Func, std::ranges::range Range1, std::ranges::range Range2, class ...Args>
  38 constexpr void test(Func&& func, Range1& r1, Range2& r2, Args&& ...args) {
  39   (void)func(r1.begin(), r1.end(), r2.begin(), r2.end(), std::forward<Args>(args)...);
  40   (void)func(r1, r2, std::forward<Args>(args)...);
  41 }
  42
  43 // (in, mid, ...)
  44 template <class Func, std::ranges::range Input, class ...Args>
  45 constexpr void test_mid(Func&& func, Input& in, std::ranges::iterator_t<Input> mid, Args&& ...args) {
  46   (void)func(in.begin(), mid, in.end(), std::forward<Args>(args)...);
  47   (void)func(in, mid, std::forward<Args>(args)...);
  48 }
  49
  50 std::mt19937 rand_gen() { return std::mt19937(); }
  51
  52 template <class T>
  53 constexpr void run_tests() {
  54   std::array input = {T{1}, T{2}, T{3}};
  55   ProxyRange in{input};
  56   std::array input2 = {T{4}, T{5}, T{6}};
  57   ProxyRange in2{input2};
  58
  59   auto mid = in.begin() + 1;
  60
  61   std::array output = {T{4}, T{5}, T{6}, T{7}, T{8}, T{9}};
  62   ProxyIterator out{output.begin()};
  63   ProxyIterator out2{output.begin() + 1};
  64   ProxyIterator out_end{output.end()};
  65
  66   T num{2};
  67   Proxy<T&> x{num};
  68   int count = 1;
  69
  70   auto unary_pred = [](const Proxy<T&>&) { return true; };
  71   auto binary_func = [](const Proxy<T>&, const Proxy<T>&) -> Proxy<T> { return Proxy<T>(T()); };
  72   auto gen = [] { return Proxy<T>(T{42}); };
  73
  74   test(std::ranges::any_of, in, unary_pred);
  75   test(std::ranges::all_of, in, unary_pred);
  76   test(std::ranges::none_of, in, unary_pred);
  77   test(std::ranges::find, in, x);
  78   test(std::ranges::find_if, in, unary_pred);
  79   test(std::ranges::find_if_not, in, unary_pred);
  80   test(std::ranges::find_first_of, in, in2);
  81   test(std::ranges::adjacent_find, in);
  82   test(std::ranges::mismatch, in, in2);
  83   test(std::ranges::equal, in, in2);
  84   test(std::ranges::lexicographical_compare, in, in2);
  85   test(std::ranges::partition_point, in, unary_pred);
  86   test(std::ranges::lower_bound, in, x);
  87   test(std::ranges::upper_bound, in, x);
  88   test(std::ranges::equal_range, in, x);
  89   test(std::ranges::binary_search, in, x);
  90
  91   test(std::ranges::min_element, in);
  92   test(std::ranges::max_element, in);
  93   test(std::ranges::minmax_element, in);
  94   test(std::ranges::count, in, x);
  95   test(std::ranges::count_if, in, unary_pred);
  96   test(std::ranges::search, in, in2);
  97   test(std::ranges::search_n, in, count, x);
  98   test(std::ranges::find_end, in, in2);
  99   test(std::ranges::is_partitioned, in, unary_pred);
 100   test(std::ranges::is_sorted, in);
 101   test(std::ranges::is_sorted_until, in);
 102   test(std::ranges::includes, in, in2);
 103   test(std::ranges::is_heap, in);
 104   test(std::ranges::is_heap_until, in);
 105   test(std::ranges::is_permutation, in, in2);
 106   test(std::ranges::for_each, in, std::identity{});
 107   std::ranges::for_each_n(in.begin(), count, std::identity{});
 108   if constexpr (std::copyable<T>) {
 109     test(std::ranges::copy, in, out);
 110     std::ranges::copy_n(in.begin(), count, out);
 111     test(std::ranges::copy_if, in, out, unary_pred);
 112     test(std::ranges::copy_backward, in, out_end);
 113   }
 114   test(std::ranges::move, in, out);
 115   test(std::ranges::move_backward, in, out_end);
 116   if constexpr (std::copyable<T>) {
 117     test(std::ranges::fill, in, x);
 118     std::ranges::fill_n(in.begin(), count, x);
 119     test(std::ranges::transform, in, out, std::identity{});
 120     test(std::ranges::transform, in, in2, out, binary_func);
 121   }
 122   test(std::ranges::generate, in, gen);
 123   std::ranges::generate_n(in.begin(), count, gen);
 124   if constexpr (std::copyable<T>) {
 125     test(std::ranges::remove_copy, in, out, x);
 126     test(std::ranges::remove_copy_if, in, out, unary_pred);
 127     test(std::ranges::replace, in, x, x);
 128     test(std::ranges::replace_if, in, unary_pred, x);
 129     test(std::ranges::replace_copy, in, out, x, x);
 130     test(std::ranges::replace_copy_if, in, out, unary_pred, x);
 131   }
 132   test(std::ranges::swap_ranges, in, in2);
 133   if constexpr (std::copyable<T>) {
 134     test(std::ranges::reverse_copy, in, out);
 135     test_mid(std::ranges::rotate_copy, in, mid, out);
 136     test(std::ranges::unique_copy, in, out);
 137     test(std::ranges::partition_copy, in, out, out2, unary_pred);
 138     test(std::ranges::partial_sort_copy, in, in2);
 139     test(std::ranges::merge, in, in2, out);
 140     test(std::ranges::set_difference, in, in2, out);
 141     test(std::ranges::set_intersection, in, in2, out);
 142     test(std::ranges::set_symmetric_difference, in, in2, out);
 143     test(std::ranges::set_union, in, in2, out);
 144   }
 145   test(std::ranges::remove, in, x);
 146   test(std::ranges::remove_if, in, unary_pred);
 147   test(std::ranges::reverse, in);
 148   test_mid(std::ranges::rotate, in, mid);
 149   if (!std::is_constant_evaluated()) // `shuffle` isn't `constexpr`.
 150     test(std::ranges::shuffle, in, rand_gen());
 151   if (!std::is_constant_evaluated()) {
 152     if constexpr (std::copyable<T>)
 153       test(std::ranges::sample, in, out, count, rand_gen());
 154   }
 155   test(std::ranges::unique, in);
 156   test(std::ranges::partition, in, unary_pred);
 157   if (!std::is_constant_evaluated())
 158     test(std::ranges::stable_partition, in, unary_pred);
 159   test(std::ranges::sort, in);
 160   if (!std::is_constant_evaluated())
 161     test(std::ranges::stable_sort, in);
 162   test_mid(std::ranges::partial_sort, in, mid);
 163   test_mid(std::ranges::nth_element, in, mid);
 164   if (!std::is_constant_evaluated())
 165     test_mid(std::ranges::inplace_merge, in, mid);
 166   test(std::ranges::make_heap, in);
 167   test(std::ranges::push_heap, in);
 168   test(std::ranges::pop_heap, in);
 169   test(std::ranges::sort_heap, in);
 170   test(std::ranges::prev_permutation, in);
 171   test(std::ranges::next_permutation, in);
 172
 173   // The algorithms that work on uninitialized memory have constraints that prevent proxy iterators from being used with
 174   // them.
 175 }
 176
 177 constexpr bool test_all() {
 178   run_tests<int>();
 179   run_tests<MoveOnly>();
 180
 181   return true;
 182 }
 183
 184 int main(int, char**) {
 185   test_all();
 186   static_assert(test_all());
 187
 188   return 0;
 189 }