Modules workaround for views::pairwise_transform (#4420)

microsoft · Feb 27, 2024 · 517b783 · 517b783
1 parent 017bc35
commit 517b783
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Showing 2 changed files with 37 additions and 3 deletions.
diff --git a/stl/inc/ranges b/stl/inc/ranges
@@ -8972,6 +8972,7 @@ namespace ranges {
  concept _Regular_invocable_with_repeated_type =
  _Regular_invocable_with_repeated_type_impl<_Fn, _Ty, make_index_sequence<_Nx>>;
 
+#if defined(__clang__) || defined(__EDG__) // TRANSITION, VSO-1975579
  template <class _Fn, class _Ty, class _Indices>
  struct _Invoke_result_with_repeated_type_impl;
 
@@ -8983,6 +8984,19 @@ namespace ranges {
  template <class _Fn, class _Ty, size_t _Nx>
  using _Invoke_result_with_repeated_type =
  _Invoke_result_with_repeated_type_impl<_Fn, _Ty, make_index_sequence<_Nx>>::type;
+#else // ^^^ no workaround / workaround vvv
+ template <class _Fn, class _Ty, size_t _Nx, class... _Types>
+ struct _Invoke_result_with_repeated_type_impl
+ : _Invoke_result_with_repeated_type_impl<_Fn, _Ty, _Nx - 1, _Ty, _Types...> {};
+
+ template <class _Fn, class _Ty, class... _Types>
+ struct _Invoke_result_with_repeated_type_impl<_Fn, _Ty, 0, _Types...> {
+ using type = invoke_result_t<_Fn, _Types...>;
+ };
+
+ template <class _Fn, class _Ty, size_t _Nx>
+ using _Invoke_result_with_repeated_type = _Invoke_result_with_repeated_type_impl<_Fn, _Ty, _Nx>::type;
+#endif // ^^^ workaround ^^^
 
  template <class _Vw, class _Fn, size_t _Nx>
  concept _Adjacent_transform_constraints =

diff --git a/tests/std/include/test_header_units_and_modules.hpp b/tests/std/include/test_header_units_and_modules.hpp
@@ -596,9 +596,29 @@ void test_random() {
 void test_ranges() {
  using namespace std;
  puts("Testing <ranges>.");
- constexpr int arr[]{11, 0, 22, 0, 33, 0, 44, 0, 55};
- assert(ranges::distance(views::filter(arr, [](int x) { return x == 0; })) == 4);
- static_assert(ranges::distance(views::filter(arr, [](int x) { return x != 0; })) == 5);
+
+ {
+ constexpr int arr[]{11, 0, 22, 0, 33, 0, 44, 0, 55};
+ assert(ranges::distance(views::filter(arr, [](int x) { return x == 0; })) == 4);
+ static_assert(ranges::distance(views::filter(arr, [](int x) { return x != 0; })) == 5);
+ }
+
+#if TEST_STANDARD >= 23
+ // Also test GH-4404 "unrecoverable error importing module 'std' with std::ranges::views::pairwise_transform"
+ {
+ constexpr array arr{10, 2, 30, 4, 50};
+
+ constexpr auto pairwise_plus = views::pairwise_transform(plus{});
+ const auto vec2 = ranges::to<vector>(arr | pairwise_plus);
+ const vector correct2{12, 32, 34, 54};
+ assert(vec2 == correct2);
+
+ constexpr auto triplewise_plus = views::adjacent_transform<3>([](int x, int y, int z) { return x + y + z; });
+ const auto vec3 = ranges::to<vector>(arr | triplewise_plus);
+ const vector correct3{42, 36, 84};
+ assert(vec3 == correct3);
+ }
+#endif // TEST_STANDARD >= 23
 }
 
 void test_ratio() {