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-no-concepts
11 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
12 
13 // class std::ranges::subrange;
14 
15 #include <ranges>
16 
17 #include <cassert>
18 #include "test_iterators.h"
19 #include "types.h"
20 
21 constexpr bool test() {
22   int buff[] = {1, 2, 3, 4, 5};
23 
24   {
25     std::ranges::subrange<MoveOnlyForwardIter, int*> a(MoveOnlyForwardIter(buff), buff + 5, 5);
26     assert(a.begin().base == buff);
27     assert(!a.empty());
28     assert(a.size() == 5);
29   }
30 
31   {
32     std::ranges::subrange<ForwardIter> b(ForwardIter(nullptr), ForwardIter(nullptr));
33     assert(b.empty());
34   }
35 
36   {
37     std::ranges::subrange<ForwardIter> c{ForwardIter(buff), ForwardIter(buff)};
38     assert(c.empty());
39   }
40 
41   {
42     std::ranges::subrange<ForwardIter> d(ForwardIter(buff), ForwardIter(buff + 1));
43     assert(!d.empty());
44   }
45 
46   {
47     bool minusWasCalled = false;
48     SizedSentinelForwardIter beg(buff, &minusWasCalled), end(buff + 5, &minusWasCalled);
49     std::ranges::subrange<SizedSentinelForwardIter> e(beg, end, 5);
50     assert(!e.empty());
51 
52     // Make sure that operator- is used to calculate size when possible.
53     minusWasCalled = false;
54     assert(e.size() == 5);
55     assert(minusWasCalled);
56   }
57 
58   return true;
59 }
60 
61 
62 int main(int, char**) {
63   test();
64   static_assert(test());
65 
66   return 0;
67 }
68