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 // <memory>
10
11 // UNSUPPORTED: c++03, c++11, c++14, c++17
12
13 // template <class Ptr> constexpr auto to_address(const Ptr& p) noexcept;
14 // Should not require a specialization of pointer_traits for Ptr.
15
16 #include <memory>
17 #include <type_traits>
18 #include <utility>
19
20 struct IntPtr {
operator ->IntPtr21 constexpr int* operator->() const { return ptr; }
22
23 int* ptr;
24 };
25
26 template <class T, bool>
27 struct TemplatedPtr {
operator ->TemplatedPtr28 constexpr T* operator->() const { return ptr; }
29
30 T* ptr;
31 };
32
33 template <template <class...> class Templ, class Ignore, class... Args>
34 struct is_valid_expansion_impl : std::false_type {};
35
36 template <template <class...> class Templ, class... Args>
37 struct is_valid_expansion_impl<Templ, decltype((void)Templ<Args...>{}, 0), Args...> : std::true_type {};
38
39 template <template <class...> class Templ, class... Args>
40 using is_valid_expansion = is_valid_expansion_impl<Templ, int, Args...>;
41
42 template <class Ptr>
43 using TestToAddressCall = decltype(std::to_address(std::declval<Ptr>()));
44
test()45 constexpr bool test() {
46 int i = 0;
47
48 static_assert(std::to_address(IntPtr{nullptr}) == nullptr);
49 static_assert(std::to_address(IntPtr{&i}) == &i);
50
51 bool b = false;
52
53 static_assert(std::to_address(TemplatedPtr<bool, true>{nullptr}) == nullptr);
54 static_assert(std::to_address(TemplatedPtr<bool, true>{&b}) == &b);
55
56 static_assert(!is_valid_expansion<TestToAddressCall, int>::value);
57 static_assert(is_valid_expansion<TestToAddressCall, IntPtr>::value);
58 static_assert(is_valid_expansion<TestToAddressCall, TemplatedPtr<bool, true>>::value);
59
60 return true;
61 }
62
main(int,char **)63 int main(int, char**) {
64 static_assert(test());
65 return 0;
66 }
67