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 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
11 
12 // class std::ranges::subrange;
13 
14 #include <ranges>
15 
16 #include <cassert>
17 #include "test_iterators.h"
18 #include "types.h"
19 
20 constexpr bool test() {
21   int buff[] = {1, 2, 3, 4, 5};
22 
23   {
24     std::ranges::subrange<MoveOnlyForwardIter, int*> a(MoveOnlyForwardIter(buff), buff + 5, 5);
25     assert(base(a.begin()) == buff);
26     assert(!a.empty());
27     assert(a.size() == 5);
28   }
29 
30   {
31     std::ranges::subrange<ForwardIter> b(ForwardIter(nullptr), ForwardIter(nullptr));
32     assert(b.empty());
33   }
34 
35   {
36     std::ranges::subrange<ForwardIter> c{ForwardIter(buff), ForwardIter(buff)};
37     assert(c.empty());
38   }
39 
40   {
41     std::ranges::subrange<ForwardIter> d(ForwardIter(buff), ForwardIter(buff + 1));
42     assert(!d.empty());
43   }
44 
45   {
46     bool minusWasCalled = false;
47     SizedSentinelForwardIter beg(buff, &minusWasCalled), end(buff + 5, &minusWasCalled);
48     std::ranges::subrange<SizedSentinelForwardIter> e(beg, end, 5);
49     assert(!e.empty());
50 
51     // Make sure that operator- is used to calculate size when possible.
52     minusWasCalled = false;
53     assert(e.size() == 5);
54     assert(minusWasCalled);
55   }
56 
57   return true;
58 }
59 
60 
61 int main(int, char**) {
62   test();
63   static_assert(test());
64 
65   return 0;
66 }
67