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 // transform_view::<iterator>::operator{<,>,<=,>=,==,!=,<=>}
13 
14 #include <ranges>
15 #include <compare>
16 
17 #include "test_macros.h"
18 #include "test_iterators.h"
19 #include "../types.h"
20 
test()21 constexpr bool test() {
22   {
23     // Test a new-school iterator with operator<=>; the transform iterator should also have operator<=>.
24     using It = three_way_contiguous_iterator<int*>;
25     static_assert(std::three_way_comparable<It>);
26     using R = std::ranges::transform_view<std::ranges::subrange<It>, PlusOne>;
27     static_assert(std::three_way_comparable<std::ranges::iterator_t<R>>);
28 
29     int a[] = {1,2,3};
30     std::same_as<R> auto r = std::ranges::subrange<It>(It(a), It(a+3)) | std::views::transform(PlusOne());
31     auto iter1 = r.begin();
32     auto iter2 = iter1 + 1;
33 
34     assert(!(iter1 < iter1));  assert(iter1 < iter2);     assert(!(iter2 < iter1));
35     assert(iter1 <= iter1);    assert(iter1 <= iter2);    assert(!(iter2 <= iter1));
36     assert(!(iter1 > iter1));  assert(!(iter1 > iter2));  assert(iter2 > iter1);
37     assert(iter1 >= iter1);    assert(!(iter1 >= iter2)); assert(iter2 >= iter1);
38     assert(iter1 == iter1);    assert(!(iter1 == iter2)); assert(iter2 == iter2);
39     assert(!(iter1 != iter1)); assert(iter1 != iter2);    assert(!(iter2 != iter2));
40 
41     assert((iter1 <=> iter2) == std::strong_ordering::less);
42     assert((iter1 <=> iter1) == std::strong_ordering::equal);
43     assert((iter2 <=> iter1) == std::strong_ordering::greater);
44   }
45 
46   {
47     // Test an old-school iterator with no operator<=>; the transform iterator shouldn't have operator<=> either.
48     using It = random_access_iterator<int*>;
49     static_assert(!std::three_way_comparable<It>);
50     using R = std::ranges::transform_view<std::ranges::subrange<It>, PlusOne>;
51     static_assert(!std::three_way_comparable<std::ranges::iterator_t<R>>);
52 
53     int a[] = {1,2,3};
54     std::same_as<R> auto r = std::ranges::subrange<It>(It(a), It(a+3)) | std::views::transform(PlusOne());
55     auto iter1 = r.begin();
56     auto iter2 = iter1 + 1;
57 
58     assert(!(iter1 < iter1));  assert(iter1 < iter2);     assert(!(iter2 < iter1));
59     assert(iter1 <= iter1);    assert(iter1 <= iter2);    assert(!(iter2 <= iter1));
60     assert(!(iter1 > iter1));  assert(!(iter1 > iter2));  assert(iter2 > iter1);
61     assert(iter1 >= iter1);    assert(!(iter1 >= iter2)); assert(iter2 >= iter1);
62     assert(iter1 == iter1);    assert(!(iter1 == iter2)); assert(iter2 == iter2);
63     assert(!(iter1 != iter1)); assert(iter1 != iter2);    assert(!(iter2 != iter2));
64   }
65 
66   return true;
67 }
68 
main(int,char **)69 int main(int, char**) {
70   test();
71   static_assert(test());
72 
73   return 0;
74 }
75