xref: /llvm-project/libcxx/test/std/ranges/range.adaptors/range.all/all_t.compile.pass.cpp (revision b8cb1dc9ea87faa8e8e9ab7a31710a8c0bb8b084)
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 // template<viewable_range R>
12 // using all_t = decltype(views::all(declval<R>()));
13 
14 #include <ranges>
15 
16 #include "test_iterators.h"
17 
18 struct View : std::ranges::view_base {
19   int *begin() const;
20   int *end() const;
21 };
22 
23 struct Range {
24   int *begin() const;
25   int *end() const;
26 };
27 
28 struct BorrowableRange {
29   int *begin() const;
30   int *end() const;
31 };
32 template<>
33 inline constexpr bool std::ranges::enable_borrowed_range<BorrowableRange> = true;
34 
35 template <class T>
36 concept HasAllT = requires {
37     typename std::views::all_t<T>;
38 };
39 
40 // When T is a view, returns decay-copy(T)
41 ASSERT_SAME_TYPE(std::views::all_t<View>, View);
42 ASSERT_SAME_TYPE(std::views::all_t<View&>, View);
43 ASSERT_SAME_TYPE(std::views::all_t<View&&>, View);
44 ASSERT_SAME_TYPE(std::views::all_t<const View>, View);
45 ASSERT_SAME_TYPE(std::views::all_t<const View&>, View);
46 ASSERT_SAME_TYPE(std::views::all_t<const View&&>, View);
47 
48 // Otherwise, when T is a reference to a range, returns ref_view<T>
49 ASSERT_SAME_TYPE(std::views::all_t<Range&>, std::ranges::ref_view<Range>);
50 ASSERT_SAME_TYPE(std::views::all_t<const Range&>, std::ranges::ref_view<const Range>);
51 ASSERT_SAME_TYPE(std::views::all_t<BorrowableRange&>, std::ranges::ref_view<BorrowableRange>);
52 ASSERT_SAME_TYPE(std::views::all_t<const BorrowableRange&>, std::ranges::ref_view<const BorrowableRange>);
53 
54 // Otherwise, returns owning_view<T>
55 ASSERT_SAME_TYPE(std::views::all_t<Range>, std::ranges::owning_view<Range>);
56 ASSERT_SAME_TYPE(std::views::all_t<Range&&>, std::ranges::owning_view<Range>);
57 static_assert(!HasAllT<const Range>);
58 static_assert(!HasAllT<const Range&&>);
59 ASSERT_SAME_TYPE(std::views::all_t<BorrowableRange>, std::ranges::owning_view<BorrowableRange>);
60 ASSERT_SAME_TYPE(std::views::all_t<BorrowableRange&&>, std::ranges::owning_view<BorrowableRange>);
61 static_assert(!HasAllT<const BorrowableRange>);
62 static_assert(!HasAllT<const BorrowableRange&&>);
63