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// constexpr auto size() requires sized_range<R>
12// constexpr auto size() const requires sized_range<const R>
13
14#include <ranges>
15
16#include <array>
17#include <cassert>
18#include <concepts>
19
20#include "test_iterators.h"
21#include "test_macros.h"
22
23template <class T>
24concept HasSize = requires (T t) {
25 t.size();
26};
27
28constexpr bool test()
29{
30 {
31 struct SubtractableIters {
32 forward_iterator<int*> begin();
33 sized_sentinel<forward_iterator<int*>> end();
34 };
35 using OwningView = std::ranges::owning_view<SubtractableIters>;
36 static_assert(std::ranges::sized_range<OwningView&>);
37 static_assert(!std::ranges::range<const OwningView&>); // no begin/end
38 static_assert(HasSize<OwningView&>);
39 static_assert(HasSize<OwningView&&>);
40 static_assert(!HasSize<const OwningView&>);
41 static_assert(!HasSize<const OwningView&&>);
42 }
43 {
44 struct NoSize {
45 bidirectional_iterator<int*> begin();
46 bidirectional_iterator<int*> end();
47 };
48 using OwningView = std::ranges::owning_view<NoSize>;
49 static_assert(!HasSize<OwningView&>);
50 static_assert(!HasSize<OwningView&&>);
51 static_assert(!HasSize<const OwningView&>);
52 static_assert(!HasSize<const OwningView&&>);
53 }
54 {
55 struct SizeMember {
56 bidirectional_iterator<int*> begin();
57 bidirectional_iterator<int*> end();
58 int size() const;
59 };
60 using OwningView = std::ranges::owning_view<SizeMember>;
61 static_assert(std::ranges::sized_range<OwningView&>);
62 static_assert(!std::ranges::range<const OwningView&>); // no begin/end
63 static_assert(HasSize<OwningView&>);
64 static_assert(HasSize<OwningView&&>);
65 static_assert(!HasSize<const OwningView&>); // not a range, therefore no size()
66 static_assert(!HasSize<const OwningView&&>);
67 }
68 {
69 // Test an empty view.
70 int a[] = {1};
71 auto ov = std::ranges::owning_view(std::ranges::subrange(a, a));
72 assert(ov.size() == 0);
73 assert(std::as_const(ov).size() == 0);
74 }
75 {
76 // Test a non-empty view.
77 int a[] = {1};
78 auto ov = std::ranges::owning_view(std::ranges::subrange(a, a+1));
79 assert(ov.size() == 1);
80 assert(std::as_const(ov).size() == 1);
81 }
82 {
83 // Test a non-view.
84 std::array<int, 2> a = {1, 2};
85 auto ov = std::ranges::owning_view(std::move(a));
86 assert(ov.size() == 2);
87 assert(std::as_const(ov).size() == 2);
88 }
89 return true;
90}
91
92int main(int, char**) {
93 test();
94 static_assert(test());
95
96 return 0;
97}
98

source code of libcxx/test/std/ranges/range.adaptors/range.all/range.owning.view/size.pass.cpp