libcxx/test/std/utilities/variant/variant.variant/variant.ctor/conv.pass.cpp

   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
  10
  11 // <variant>
  12
  13 // template <class ...Types> class variant;
  14
  15 // template <class T> constexpr variant(T&&) noexcept(see below);
  16
  17 #include <variant>
  18 #include <string>
  19 #include <memory>
  20
  21 #include "variant_test_helpers.h"
  22
  23 int main(int, char**)
  24 {
  25   static_assert(!std::is_constructible<std::variant<int, int>, int>::value, "");
  26   static_assert(!std::is_constructible<std::variant<long, long long>, int>::value, "");
  27   static_assert(std::is_constructible<std::variant<char>, int>::value == VariantAllowsNarrowingConversions, "");
  28
  29   static_assert(std::is_constructible<std::variant<std::string, float>, int>::value == VariantAllowsNarrowingConversions, "");
  30   static_assert(std::is_constructible<std::variant<std::string, double>, int>::value == VariantAllowsNarrowingConversions, "");
  31   static_assert(!std::is_constructible<std::variant<std::string, bool>, int>::value, "");
  32
  33   static_assert(!std::is_constructible<std::variant<int, bool>, decltype("meow")>::value, "");
  34   static_assert(!std::is_constructible<std::variant<int, const bool>, decltype("meow")>::value, "");
  35   static_assert(!std::is_constructible<std::variant<int, const volatile bool>, decltype("meow")>::value, "");
  36
  37   static_assert(!std::is_constructible<std::variant<bool>, std::true_type>::value, "");
  38   static_assert(!std::is_constructible<std::variant<bool>, std::unique_ptr<char> >::value, "");
  39   static_assert(!std::is_constructible<std::variant<bool>, decltype(nullptr)>::value, "");
  40
  41   return 0;
  42 }