[libc++] Add test for algorithm result type alias declarations

[var-const]

libcxx/test/std/algorithms/ranges_result_alias_declarations.compile.pass.cpp

10

You probably need to add UNSUPPORTED.

19

Optional nit: any reason not to use same_as?

22

Do we also need to test that the corresponding algorithm returns the right type?

static_assert(std::is_same_v<in_in_result<int, long>, mismatch_result<int, long>>);
static_assert(std::is_same_v<decltype(std::ranges::mismatch(i1, s1, i2, s2)), in_in_result<int, long>>);

[var-const]

Nit: s/algorihtm/algorithm/ in the name.

[var-const]

libcxx/test/std/algorithms/ranges_result_alias_declarations.compile.pass.cpp

22

Although to be fair, we do that already in the algorithm test files, so this would be duplicative.

[philnik]

• Address comments

libcxx/test/std/algorithms/ranges_result_alias_declarations.compile.pass.cpp

19

is_same reads more naturally to me, but I think nothing about either of them is objectively better than the other one. Using same_as might be marginally more expensive for the compiler, but who knows (or cares).

22

Exactly. This test only exists to ensure that the aliases exist. There are probably a few tests where we don't actually check that, since is_in_result<int, long> and swap_ranges_result<int, long> are indistinguishable from each other.

[var-const]

Thanks!

libcxx/test/std/algorithms/ranges_result_alias_declarations.compile.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+// UNSUPPORTED: libcpp-has-no-incomplete-ranges
+
+// <algorithm>
+
+// ensure that all result alias declarations are defined
+
+#include <algorithm>
+#include <type_traits>
+
+using namespace std::ranges;
+
+static_assert(std::is_same_v<in_fun_result<int, long>, for_each_result<int, long>>);
+static_assert(std::is_same_v<in_fun_result<int, long>, for_each_n_result<int, long>>);
+
+static_assert(std::is_same_v<in_in_result<int, long>, mismatch_result<int, long>>);
+static_assert(std::is_same_v<in_in_result<int, long>, swap_ranges_result<int, long>>);
+
+static_assert(std::is_same_v<in_out_result<int, long>, copy_result<int, long>>);
+static_assert(std::is_same_v<in_out_result<int, long>, copy_n_result<int, long>>);
+static_assert(std::is_same_v<in_out_result<int, long>, copy_if_result<int, long>>);
+static_assert(std::is_same_v<in_out_result<int, long>, copy_backward_result<int, long>>);
+static_assert(std::is_same_v<in_out_result<int, long>, move_result<int, long>>);
+static_assert(std::is_same_v<in_out_result<int, long>, move_backward_result<int, long>>);
+// static_assert(std::is_same_v<in_out_result<int, long>, partial_sort_copy_result<int, long>>);
+// static_assert(std::is_same_v<in_out_result<int, long>, remove_copy_result<int, long>>);
+// static_assert(std::is_same_v<in_out_result<int, long>, remove_copy_if_result<int, long>>);
+// static_assert(std::is_same_v<in_out_result<int, long>, replace_copy_result<int, long>>);
+// static_assert(std::is_same_v<in_out_result<int, long>, replace_copy_if_result<int, long>>);
+// static_assert(std::is_same_v<in_out_result<int, long>, reverse_copy_result<int, long>>);
+// static_assert(std::is_same_v<in_out_result<int, long>, rotate_copy_result<int, long>>);
+// static_assert(std::is_same_v<in_out_result<int, long>, set_difference_result<int, long>>);
+static_assert(std::is_same_v<in_out_result<int, long>, unary_transform_result<int, long>>);
+static_assert(std::is_same_v<in_out_result<int, long>, uninitialized_copy_result<int, long>>);
+static_assert(std::is_same_v<in_out_result<int, long>, uninitialized_copy_n_result<int, long>>);
+static_assert(std::is_same_v<in_out_result<int, long>, uninitialized_move_result<int, long>>);
+static_assert(std::is_same_v<in_out_result<int, long>, uninitialized_move_n_result<int, long>>);
+// static_assert(std::is_same_v<in_out_result<int, long>, unique_copy_result<int, long>>);
+
+static_assert(std::is_same_v<in_in_out_result<int, long, char>, binary_transform_result<int, long, char>>);
+static_assert(std::is_same_v<in_in_out_result<int, long, char>, merge_result<int, long, char>>);
+// static_assert(std::is_same_v<in_in_out_result<int, long, char>, set_symmetric_difference_result<int, long, char>>);
+// static_assert(std::is_same_v<in_in_out_result<int, long, char>, set_union_result<int, long, char>>);
+// static_assert(std::is_same_v<in_in_out_result<int, long, char>, set_intersection_result<int, long, char>>);
+
+// static_assert(std::is_same_v<in_out_out_result<int, long, char>, partition_copy_result<int, long, char>>);
+
+static_assert(std::is_same_v<min_max_result<int>, minmax_result<int>>);
+static_assert(std::is_same_v<min_max_result<int>, minmax_element_result<int>>);
+
+// static_assert(std::is_same_v<in_found_result<int>, next_permutation_result<int>>);
+// static_assert(std::is_same_v<in_found_result<int>, prev_permutation_result<int>>);
+
+// static_assert(std::is_same_v<out_value_result<int>, iota_result<int>>);