libcxx/test/std/algorithms/alg.modifying.operations/alg.transform/ranges.transform.binary.iterator.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 // template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
  14 //          weakly_incrementable O, copy_constructible F, class Proj1 = identity,
  15 //          class Proj2 = identity>
  16 //   requires indirectly_writable<O, indirect_result_t<F&, projected<I1, Proj1>,
  17 //                                          projected<I2, Proj2>>>
  18 //   constexpr ranges::binary_transform_result<I1, I2, O>
  19 //     ranges::transform(I1 first1, S1 last1, I2 first2, S2 last2, O result,
  20 //                       F binary_op, Proj1 proj1 = {}, Proj2 proj2 = {});
  21
  22 // The range overloads are tested in ranges.tranform.binary.range.pass.cpp.
  23
  24 #include <algorithm>
  25 #include <array>
  26 #include <cassert>
  27 #include <functional>
  28 #include <ranges>
  29
  30 #include "test_iterators.h"
  31 #include "almost_satisfies_types.h"
  32
  33 struct BinaryFunc {
  34   int operator()(int, int);
  35 };
  36
  37 template <class It, class Sent = It>
  38 concept HasTransformIt =
  39     requires(It it, Sent sent, int* out) { std::ranges::transform(it, sent, it, sent, out, BinaryFunc{}); };
  40 static_assert(HasTransformIt<int*>);
  41 static_assert(!HasTransformIt<InputIteratorNotDerivedFrom>);
  42 static_assert(!HasTransformIt<InputIteratorNotIndirectlyReadable>);
  43 static_assert(!HasTransformIt<InputIteratorNotInputOrOutputIterator>);
  44 static_assert(!HasTransformIt<cpp20_input_iterator<int*>, SentinelForNotSemiregular>);
  45 static_assert(!HasTransformIt<cpp20_input_iterator<int*>, InputRangeNotSentinelEqualityComparableWith>);
  46
  47 template <class It>
  48 concept HasTransformOut = requires(int* it, int* sent, It out, std::array<int, 2> range) {
  49   std::ranges::transform(it, sent, it, sent, out, BinaryFunc{});
  50 };
  51 static_assert(HasTransformOut<int*>);
  52 static_assert(!HasTransformOut<WeaklyIncrementableNotMovable>);
  53
  54 // check indirectly_readable
  55 static_assert(HasTransformOut<char*>);
  56 static_assert(!HasTransformOut<int**>);
  57
  58 struct MoveOnlyFunctor {
  59   MoveOnlyFunctor(const MoveOnlyFunctor&) = delete;
  60   MoveOnlyFunctor(MoveOnlyFunctor&&)      = default;
  61   int operator()(int, int);
  62 };
  63
  64 template <class Func>
  65 concept HasTransformFuncBinary = requires(int* it, int* sent, int* out, std::array<int, 2> range, Func func) {
  66   std::ranges::transform(it, sent, it, sent, out, func);
  67 };
  68 static_assert(HasTransformFuncBinary<BinaryFunc>);
  69 static_assert(!HasTransformFuncBinary<MoveOnlyFunctor>);
  70
  71 static_assert(std::is_same_v<std::ranges::binary_transform_result<int, long, char>,
  72                              std::ranges::in_in_out_result<int, long, char>>);
  73
  74 // clang-format off
  75 template <class In1, class In2, class Out, class Sent1, class Sent2>
  76 constexpr bool test_iterators() {
  77   { // simple
  78     int a[] = {1, 2, 3, 4, 5};
  79     int b[] = {5, 4, 3, 2, 1};
  80     int c[5];
  81
  82     std::same_as<std::ranges::in_in_out_result<In1, In2, Out>> decltype(auto) ret = std::ranges::transform(
  83         In1(a), Sent1(In1(a + 5)), In2(b), Sent2(In2(b + 5)), Out(c), [](int i, int j) { return i + j; });
  84
  85     assert((std::to_array(c) == std::array{6, 6, 6, 6, 6}));
  86     assert(base(ret.in1) == a + 5);
  87     assert(base(ret.in2) == b + 5);
  88     assert(base(ret.out) == c + 5);
  89   }
  90
  91   { // first range empty
  92     int a[] = {};
  93     int b[] = {5, 4, 3, 2, 1};
  94     int c[5];
  95
  96     auto ret = std::ranges::transform(
  97         In1(a), Sent1(In1(a)), In2(b), Sent2(In2(b + 5)), Out(c), [](int i, int j) { return i + j; });
  98
  99     assert(base(ret.in1) == a);
 100     assert(base(ret.in2) == b);
 101     assert(base(ret.out) == c);
 102   }
 103
 104   { // second range empty
 105     int a[] = {5, 4, 3, 2, 1};
 106     int b[] = {};
 107     int c[5];
 108
 109     auto ret = std::ranges::transform(
 110         In1(a), Sent1(In1(a + 5)), In2(b), Sent2(In2(b)), Out(c), [](int i, int j) { return i + j; });
 111
 112     assert(base(ret.in1) == a);
 113     assert(base(ret.in2) == b);
 114     assert(base(ret.out) == c);
 115   }
 116
 117   { // both ranges empty
 118     int a[] = {};
 119     int b[] = {};
 120     int c[5];
 121
 122     auto ret = std::ranges::transform(
 123         In1(a), Sent1(In1(a)), In2(b), Sent2(In2(b)), Out(c), [](int i, int j) { return i + j; });
 124
 125     assert(base(ret.in1) == a);
 126     assert(base(ret.in2) == b);
 127     assert(base(ret.out) == c);
 128   }
 129
 130   { // first range one element
 131     int a[] = {2};
 132     int b[] = {5, 4, 3, 2, 1};
 133     int c[5];
 134
 135     auto ret = std::ranges::transform(
 136         In1(a), Sent1(In1(a + 1)), In2(b), Sent2(In2(b + 5)), Out(c), [](int i, int j) { return i + j; });
 137
 138     assert(c[0] == 7);
 139     assert(base(ret.in1) == a + 1);
 140     assert(base(ret.in2) == b + 1);
 141     assert(base(ret.out) == c + 1);
 142   }
 143
 144   { // second range contains one element
 145     int a[] = {5, 4, 3, 2, 1};
 146     int b[] = {4};
 147     int c[5];
 148
 149     auto ret = std::ranges::transform(
 150         In1(a), Sent1(In1(a + 5)), In2(b), Sent2(In2(b + 1)), Out(c), [](int i, int j) { return i + j; });
 151
 152     assert(c[0] == 9);
 153     assert(base(ret.in1) == a + 1);
 154     assert(base(ret.in2) == b + 1);
 155     assert(base(ret.out) == c + 1);
 156   }
 157
 158   { // check that the transform function and projection call counts are correct
 159     int predCount = 0;
 160     int proj1Count = 0;
 161     int proj2Count = 0;
 162     auto pred = [&](int, int) { ++predCount; return 1; };
 163     auto proj1 = [&](int) { ++proj1Count; return 0; };
 164     auto proj2 = [&](int) { ++proj2Count; return 0; };
 165     int a[] = {1, 2, 3, 4};
 166     int b[] = {1, 2, 3, 4};
 167     std::array<int, 4> c;
 168     std::ranges::transform(In1(a), Sent1(In1(a + 4)), In2(b), Sent2(In2(b + 4)), Out(c.data()), pred, proj1, proj2);
 169     assert(predCount == 4);
 170     assert(proj1Count == 4);
 171     assert(proj2Count == 4);
 172     assert((c == std::array{1, 1, 1, 1}));
 173   }
 174
 175   return true;
 176 }
 177 // clang-format on
 178
 179 template <class In2, class Out, class Sent2 = In2>
 180 constexpr void test_iterator_in1() {
 181   test_iterators<cpp17_input_iterator<int*>, In2, Out, sentinel_wrapper<cpp17_input_iterator<int*>>, Sent2>();
 182   test_iterators<cpp20_input_iterator<int*>, In2, Out, sentinel_wrapper<cpp20_input_iterator<int*>>, Sent2>();
 183   test_iterators<forward_iterator<int*>, In2, Out, forward_iterator<int*>, Sent2>();
 184   test_iterators<bidirectional_iterator<int*>, In2, Out, bidirectional_iterator<int*>, Sent2>();
 185   test_iterators<random_access_iterator<int*>, In2, Out, random_access_iterator<int*>, Sent2>();
 186   test_iterators<contiguous_iterator<int*>, In2, Out, contiguous_iterator<int*>, Sent2>();
 187   test_iterators<int*, In2, Out, int*, Sent2>();
 188 }
 189
 190 template <class Out>
 191 constexpr void test_iterators_in1_in2() {
 192   test_iterator_in1<cpp17_input_iterator<int*>, Out, sentinel_wrapper<cpp17_input_iterator<int*>>>();
 193   test_iterator_in1<cpp20_input_iterator<int*>, Out, sentinel_wrapper<cpp20_input_iterator<int*>>>();
 194   test_iterator_in1<forward_iterator<int*>, Out>();
 195   test_iterator_in1<bidirectional_iterator<int*>, Out>();
 196   test_iterator_in1<random_access_iterator<int*>, Out>();
 197   test_iterator_in1<contiguous_iterator<int*>, Out>();
 198   test_iterator_in1<int*, Out>();
 199 }
 200
 201 constexpr bool test() {
 202   test_iterators_in1_in2<cpp17_output_iterator<int*>>();
 203   test_iterators_in1_in2<cpp20_output_iterator<int*>>();
 204   test_iterators_in1_in2<forward_iterator<int*>>();
 205   test_iterators_in1_in2<bidirectional_iterator<int*>>();
 206   test_iterators_in1_in2<random_access_iterator<int*>>();
 207   test_iterators_in1_in2<contiguous_iterator<int*>>();
 208   test_iterators_in1_in2<int*>();
 209
 210   { // check that returning another type from the projection works
 211     struct S { int i; int other; };
 212     S a[] = { S{0, 0}, S{1, 0}, S{3, 0}, S{10, 0} };
 213     S b[] = { S{0, 10}, S{1, 20}, S{3, 30}, S{10, 40} };
 214     std::array<int, 4> c;
 215     std::ranges::transform(a, a + 4, b, b + 4, c.begin(), [](S s1, S s2) { return s1.i + s2.other; });
 216     assert((c == std::array{10, 21, 33, 50}));
 217   }
 218
 219   return true;
 220 }
 221
 222 int main(int, char**) {
 223   test();
 224   static_assert(test());
 225
 226   return 0;
 227 }