[libc++] Split ranges.transform.binary.pass.cpp up

`ranges.transform.binary.pass.cpp` took ~25s to compile. `ranges.transform.binary.range.pass.cpp` and `ranges.transform.binary.iterator.pass.cpp` take ~13s each.

Reviewed By: ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D142183

Author: philnik777

libcxx/test/std/algorithms/alg.modifying.operations/alg.transform/ranges.transform.binary.iterator.pass.cpp

@@ -0,0 +1,227 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// <algorithm>
+
+// template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
+//          weakly_incrementable O, copy_constructible F, class Proj1 = identity,
+//          class Proj2 = identity>
+//   requires indirectly_writable<O, indirect_result_t<F&, projected<I1, Proj1>,
+//                                          projected<I2, Proj2>>>
+//   constexpr ranges::binary_transform_result<I1, I2, O>
+//     ranges::transform(I1 first1, S1 last1, I2 first2, S2 last2, O result,
+//                       F binary_op, Proj1 proj1 = {}, Proj2 proj2 = {});
+
+// The range overloads are tested in ranges.tranform.binary.range.pass.cpp.
+
+#include <algorithm>
+#include <array>
+#include <cassert>
+#include <functional>
+#include <ranges>
+
+#include "test_iterators.h"
+#include "almost_satisfies_types.h"
+
+struct BinaryFunc {
+  int operator()(int, int);
+};
+
+template <class It, class Sent = It>
+concept HasTransformIt =
+    requires(It it, Sent sent, int* out) { std::ranges::transform(it, sent, it, sent, out, BinaryFunc{}); };
+static_assert(HasTransformIt<int*>);
+static_assert(!HasTransformIt<InputIteratorNotDerivedFrom>);
+static_assert(!HasTransformIt<InputIteratorNotIndirectlyReadable>);
+static_assert(!HasTransformIt<InputIteratorNotInputOrOutputIterator>);
+static_assert(!HasTransformIt<cpp20_input_iterator<int*>, SentinelForNotSemiregular>);
+static_assert(!HasTransformIt<cpp20_input_iterator<int*>, InputRangeNotSentinelEqualityComparableWith>);
+
+template <class It>
+concept HasTransformOut = requires(int* it, int* sent, It out, std::array<int, 2> range) {
+  std::ranges::transform(it, sent, it, sent, out, BinaryFunc{});
+};
+static_assert(HasTransformOut<int*>);
+static_assert(!HasTransformOut<WeaklyIncrementableNotMovable>);
+
+// check indirectly_readable
+static_assert(HasTransformOut<char*>);
+static_assert(!HasTransformOut<int**>);
+
+struct MoveOnlyFunctor {
+  MoveOnlyFunctor(const MoveOnlyFunctor&) = delete;
+  MoveOnlyFunctor(MoveOnlyFunctor&&)      = default;
+  int operator()(int, int);
+};
+
+template <class Func>
+concept HasTransformFuncBinary = requires(int* it, int* sent, int* out, std::array<int, 2> range, Func func) {
+  std::ranges::transform(it, sent, it, sent, out, func);
+};
+static_assert(HasTransformFuncBinary<BinaryFunc>);
+static_assert(!HasTransformFuncBinary<MoveOnlyFunctor>);
+
+static_assert(std::is_same_v<std::ranges::binary_transform_result<int, long, char>,
+                             std::ranges::in_in_out_result<int, long, char>>);
+
+// clang-format off
+template <class In1, class In2, class Out, class Sent1, class Sent2>
+constexpr bool test_iterators() {
+  { // simple
+    int a[] = {1, 2, 3, 4, 5};
+    int b[] = {5, 4, 3, 2, 1};
+    int c[5];
+
+    std::same_as<std::ranges::in_in_out_result<In1, In2, Out>> decltype(auto) ret = std::ranges::transform(
+        In1(a), Sent1(In1(a + 5)), In2(b), Sent2(In2(b + 5)), Out(c), [](int i, int j) { return i + j; });
+
+    assert((std::to_array(c) == std::array{6, 6, 6, 6, 6}));
+    assert(base(ret.in1) == a + 5);
+    assert(base(ret.in2) == b + 5);
+    assert(base(ret.out) == c + 5);
+  }
+
+  { // first range empty
+    int a[] = {};
+    int b[] = {5, 4, 3, 2, 1};
+    int c[5];
+
+    auto ret = std::ranges::transform(
+        In1(a), Sent1(In1(a)), In2(b), Sent2(In2(b + 5)), Out(c), [](int i, int j) { return i + j; });
+
+    assert(base(ret.in1) == a);
+    assert(base(ret.in2) == b);
+    assert(base(ret.out) == c);
+  }
+
+  { // second range empty
+    int a[] = {5, 4, 3, 2, 1};
+    int b[] = {};
+    int c[5];
+
+    auto ret = std::ranges::transform(
+        In1(a), Sent1(In1(a + 5)), In2(b), Sent2(In2(b)), Out(c), [](int i, int j) { return i + j; });
+
+    assert(base(ret.in1) == a);
+    assert(base(ret.in2) == b);
+    assert(base(ret.out) == c);
+  }
+
+  { // both ranges empty
+    int a[] = {};
+    int b[] = {};
+    int c[5];
+
+    auto ret = std::ranges::transform(
+        In1(a), Sent1(In1(a)), In2(b), Sent2(In2(b)), Out(c), [](int i, int j) { return i + j; });
+
+    assert(base(ret.in1) == a);
+    assert(base(ret.in2) == b);
+    assert(base(ret.out) == c);
+  }
+
+  { // first range one element
+    int a[] = {2};
+    int b[] = {5, 4, 3, 2, 1};
+    int c[5];
+
+    auto ret = std::ranges::transform(
+        In1(a), Sent1(In1(a + 1)), In2(b), Sent2(In2(b + 5)), Out(c), [](int i, int j) { return i + j; });
+
+    assert(c[0] == 7);
+    assert(base(ret.in1) == a + 1);
+    assert(base(ret.in2) == b + 1);
+    assert(base(ret.out) == c + 1);
+  }
+
+  { // second range contains one element
+    int a[] = {5, 4, 3, 2, 1};
+    int b[] = {4};
+    int c[5];
+
+    auto ret = std::ranges::transform(
+        In1(a), Sent1(In1(a + 5)), In2(b), Sent2(In2(b + 1)), Out(c), [](int i, int j) { return i + j; });
+
+    assert(c[0] == 9);
+    assert(base(ret.in1) == a + 1);
+    assert(base(ret.in2) == b + 1);
+    assert(base(ret.out) == c + 1);
+  }
+
+  { // check that the transform function and projection call counts are correct
+    int predCount = 0;
+    int proj1Count = 0;
+    int proj2Count = 0;
+    auto pred = [&](int, int) { ++predCount; return 1; };
+    auto proj1 = [&](int) { ++proj1Count; return 0; };
+    auto proj2 = [&](int) { ++proj2Count; return 0; };
+    int a[] = {1, 2, 3, 4};
+    int b[] = {1, 2, 3, 4};
+    std::array<int, 4> c;
+    std::ranges::transform(In1(a), Sent1(In1(a + 4)), In2(b), Sent2(In2(b + 4)), Out(c.data()), pred, proj1, proj2);
+    assert(predCount == 4);
+    assert(proj1Count == 4);
+    assert(proj2Count == 4);
+    assert((c == std::array{1, 1, 1, 1}));
+  }
+
+  return true;
+}
+// clang-format on
+
+template <class In2, class Out, class Sent2 = In2>
+constexpr void test_iterator_in1() {
+  test_iterators<cpp17_input_iterator<int*>, In2, Out, sentinel_wrapper<cpp17_input_iterator<int*>>, Sent2>();
+  test_iterators<cpp20_input_iterator<int*>, In2, Out, sentinel_wrapper<cpp20_input_iterator<int*>>, Sent2>();
+  test_iterators<forward_iterator<int*>, In2, Out, forward_iterator<int*>, Sent2>();
+  test_iterators<bidirectional_iterator<int*>, In2, Out, bidirectional_iterator<int*>, Sent2>();
+  test_iterators<random_access_iterator<int*>, In2, Out, random_access_iterator<int*>, Sent2>();
+  test_iterators<contiguous_iterator<int*>, In2, Out, contiguous_iterator<int*>, Sent2>();
+  test_iterators<int*, In2, Out, int*, Sent2>();
+}
+
+template <class Out>
+constexpr void test_iterators_in1_in2() {
+  test_iterator_in1<cpp17_input_iterator<int*>, Out, sentinel_wrapper<cpp17_input_iterator<int*>>>();
+  test_iterator_in1<cpp20_input_iterator<int*>, Out, sentinel_wrapper<cpp20_input_iterator<int*>>>();
+  test_iterator_in1<forward_iterator<int*>, Out>();
+  test_iterator_in1<bidirectional_iterator<int*>, Out>();
+  test_iterator_in1<random_access_iterator<int*>, Out>();
+  test_iterator_in1<contiguous_iterator<int*>, Out>();
+  test_iterator_in1<int*, Out>();
+}
+
+constexpr bool test() {
+  test_iterators_in1_in2<cpp17_output_iterator<int*>>();
+  test_iterators_in1_in2<cpp20_output_iterator<int*>>();
+  test_iterators_in1_in2<forward_iterator<int*>>();
+  test_iterators_in1_in2<bidirectional_iterator<int*>>();
+  test_iterators_in1_in2<random_access_iterator<int*>>();
+  test_iterators_in1_in2<contiguous_iterator<int*>>();
+  test_iterators_in1_in2<int*>();
+
+  { // check that returning another type from the projection works
+    struct S { int i; int other; };
+    S a[] = { S{0, 0}, S{1, 0}, S{3, 0}, S{10, 0} };
+    S b[] = { S{0, 10}, S{1, 20}, S{3, 30}, S{10, 40} };
+    std::array<int, 4> c;
+    std::ranges::transform(a, a + 4, b, b + 4, c.begin(), [](S s1, S s2) { return s1.i + s2.other; });
+    assert((c == std::array{10, 21, 33, 50}));
+  }
+
+  return true;
+}
+
+int main(int, char**) {
+  test();
+  static_assert(test());
+
+  return 0;
+}