xref: /llvm-project/libcxx/test/std/ranges/range.adaptors/range.transform/ctor.view_function.pass.cpp (revision 40aaa272f145e633b29d5e70a4590cc425801f7e)
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 transform_view(View, F); // explicit since C++23
12 
13 #include <cassert>
14 #include <ranges>
15 
16 #include "test_convertible.h"
17 #include "test_macros.h"
18 
19 struct Range : std::ranges::view_base {
RangeRange20   constexpr explicit Range(int* b, int* e) : begin_(b), end_(e) {}
beginRange21   constexpr int* begin() const { return begin_; }
endRange22   constexpr int* end() const { return end_; }
23 
24 private:
25   int* begin_;
26   int* end_;
27 };
28 
29 struct F {
operator ()F30   constexpr int operator()(int i) const { return i + 100; }
31 };
32 
33 // SFINAE tests.
34 
35 #if TEST_STD_VER >= 23
36 
37 static_assert(!test_convertible<std::ranges::transform_view<Range, F>, Range, F>(),
38               "This constructor must be explicit");
39 
40 #else
41 
42 static_assert( test_convertible<std::ranges::transform_view<Range, F>, Range, F>(),
43               "This constructor must not be explicit");
44 
45 #endif // TEST_STD_VER >= 23
46 
test()47 constexpr bool test() {
48   int buff[] = {1, 2, 3, 4, 5, 6, 7, 8};
49 
50   {
51     Range range(buff, buff + 8);
52     F f;
53     std::ranges::transform_view<Range, F> view(range, f);
54     assert(view[0] == 101);
55     assert(view[1] == 102);
56     // ...
57     assert(view[7] == 108);
58   }
59 
60   return true;
61 }
62 
main(int,char **)63 int main(int, char**) {
64   test();
65   static_assert(test());
66 
67   return 0;
68 }
69