libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/default.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 // <optional>
  11
  12 // constexpr optional() noexcept;
  13
  14 #include <optional>
  15 #include <type_traits>
  16 #include <cassert>
  17
  18 #include "test_macros.h"
  19 #include "archetypes.h"
  20
  21 using std::optional;
  22
  23 template <class Opt>
  24 void
  25 test_constexpr()
  26 {
  27     static_assert(std::is_nothrow_default_constructible<Opt>::value, "");
  28     static_assert(std::is_trivially_destructible<Opt>::value, "");
  29     static_assert(std::is_trivially_destructible<typename Opt::value_type>::value, "");
  30
  31     constexpr Opt opt;
  32     static_assert(static_cast<bool>(opt) == false, "");
  33
  34     struct test_constexpr_ctor
  35         : public Opt
  36     {
  37         constexpr test_constexpr_ctor() {}
  38     };
  39 }
  40
  41 template <class Opt>
  42 void
  43 test()
  44 {
  45     static_assert(std::is_nothrow_default_constructible<Opt>::value, "");
  46     static_assert(!std::is_trivially_destructible<Opt>::value, "");
  47     static_assert(!std::is_trivially_destructible<typename Opt::value_type>::value, "");
  48     {
  49         Opt opt;
  50         assert(static_cast<bool>(opt) == false);
  51     }
  52     {
  53         const Opt opt;
  54         assert(static_cast<bool>(opt) == false);
  55     }
  56
  57     struct test_constexpr_ctor
  58         : public Opt
  59     {
  60         constexpr test_constexpr_ctor() {}
  61     };
  62 }
  63
  64 int main(int, char**)
  65 {
  66     test_constexpr<optional<int>>();
  67     test_constexpr<optional<int*>>();
  68     test_constexpr<optional<ImplicitTypes::NoCtors>>();
  69     test_constexpr<optional<NonTrivialTypes::NoCtors>>();
  70     test_constexpr<optional<NonConstexprTypes::NoCtors>>();
  71     test<optional<NonLiteralTypes::NoCtors>>();
  72     // EXTENSIONS
  73 #if defined(_LIBCPP_VERSION) && 0 // FIXME these extensions are currently disabled.
  74     test_constexpr<optional<int&>>();
  75     test_constexpr<optional<const int&>>();
  76     test_constexpr<optional<int&>>();
  77     test_constexpr<optional<NonLiteralTypes::NoCtors&>>();
  78     test_constexpr<optional<NonLiteralTypes::NoCtors&&>>();
  79 #endif
  80
  81   return 0;
  82 }