xref: /llvm-project/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp (revision cbe768ec694d4b374cbb84eb32a2ffcde82a0f7b)
1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // <algorithm>
11 
12 // template<BidirectionalIterator InIter, BidirectionalIterator OutIter>
13 //   requires OutputIterator<OutIter, InIter::reference>
14 //   constexpr OutIter   // constexpr after C++17
15 //   copy_backward(InIter first, InIter last, OutIter result);
16 
17 #include <algorithm>
18 #include <cassert>
19 
20 #include "test_macros.h"
21 #include "test_iterators.h"
22 #include "user_defined_integral.hpp"
23 
24 // #if TEST_STD_VER > 17
25 // TEST_CONSTEXPR bool test_constexpr() {
26 //     int ia[] = {1, 2, 3, 4, 5};
27 //     int ic[] = {6, 6, 6, 6, 6, 6, 6};
28 //
29 // 	size_t N = std::size(ia);
30 // 	auto p = std::copy_backward(std::begin(ia), std::end(ia), std::begin(ic) + N);
31 // 	return std::equal(std::begin(ic), p, std::begin(ia))
32 // 	    && std::all_of(p, std::end(ic), [](int a){return a == 6;})
33 // 	    ;
34 //     }
35 // #endif
36 
37 template <class InIter, class OutIter>
38 void
39 test()
40 {
41     const unsigned N = 1000;
42     int ia[N];
43     for (unsigned i = 0; i < N; ++i)
44         ia[i] = i;
45     int ib[N] = {0};
46 
47     OutIter r = std::copy_backward(InIter(ia), InIter(ia+N), OutIter(ib+N));
48     assert(base(r) == ib);
49     for (unsigned i = 0; i < N; ++i)
50         assert(ia[i] == ib[i]);
51 }
52 
53 int main()
54 {
55     test<bidirectional_iterator<const int*>, bidirectional_iterator<int*> >();
56     test<bidirectional_iterator<const int*>, random_access_iterator<int*> >();
57     test<bidirectional_iterator<const int*>, int*>();
58 
59     test<random_access_iterator<const int*>, bidirectional_iterator<int*> >();
60     test<random_access_iterator<const int*>, random_access_iterator<int*> >();
61     test<random_access_iterator<const int*>, int*>();
62 
63     test<const int*, bidirectional_iterator<int*> >();
64     test<const int*, random_access_iterator<int*> >();
65     test<const int*, int*>();
66 
67 // #if TEST_STD_VER > 17
68 //     static_assert(test_constexpr());
69 // #endif
70 }
71