xref: /llvm-project/libcxx/test/std/utilities/variant/variant.variant/variant.assign/conv.pass.cpp (revision cc89063bff0f73ec7049a1dcb5d4688ae6806941)
1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // UNSUPPORTED: c++98, c++03, c++11, c++14
11 
12 // <variant>
13 
14 // template <class ...Types> class variant;
15 
16 // template <class T>
17 // variant& operator=(T&&) noexcept(see below);
18 
19 #include <variant>
20 #include <string>
21 #include <memory>
22 
23 #include "variant_test_helpers.h"
24 
25 int main(int, char**)
26 {
27   static_assert(!std::is_assignable<std::variant<int, int>, int>::value, "");
28   static_assert(!std::is_assignable<std::variant<long, long long>, int>::value, "");
29   static_assert(std::is_assignable<std::variant<char>, int>::value == VariantAllowsNarrowingConversions, "");
30 
31   static_assert(std::is_assignable<std::variant<std::string, float>, int>::value == VariantAllowsNarrowingConversions, "");
32   static_assert(std::is_assignable<std::variant<std::string, double>, int>::value == VariantAllowsNarrowingConversions, "");
33   static_assert(!std::is_assignable<std::variant<std::string, bool>, int>::value, "");
34 
35   static_assert(!std::is_assignable<std::variant<int, bool>, decltype("meow")>::value, "");
36   static_assert(!std::is_assignable<std::variant<int, const bool>, decltype("meow")>::value, "");
37   static_assert(!std::is_assignable<std::variant<int, const volatile bool>, decltype("meow")>::value, "");
38 
39   static_assert(!std::is_assignable<std::variant<bool>, std::true_type>::value, "");
40   static_assert(!std::is_assignable<std::variant<bool>, std::unique_ptr<char> >::value, "");
41   static_assert(!std::is_assignable<std::variant<bool>, decltype(nullptr)>::value, "");
42 
43 }
44