test/std/utilities/optional/optional.object/optional.object.mod/reset.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is dual licensed under the MIT and the University of Illinois Open
   6 // Source Licenses. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 // UNSUPPORTED: c++98, c++03, c++11, c++14
  11
  12 // <optional>
  13
  14 // void reset() noexcept;
  15
  16 #include <optional>
  17 #include <type_traits>
  18 #include <cassert>
  19
  20 using std::optional;
  21
  22 struct X
  23 {
  24     static bool dtor_called;
  25     ~X() {dtor_called = true;}
  26 };
  27
  28 bool X::dtor_called = false;
  29
  30 int main()
  31 {
  32     {
  33         optional<int> opt;
  34         static_assert(noexcept(opt.reset()) == true, "");
  35         opt.reset();
  36         assert(static_cast<bool>(opt) == false);
  37     }
  38     {
  39         optional<int> opt(3);
  40         opt.reset();
  41         assert(static_cast<bool>(opt) == false);
  42     }
  43     {
  44         optional<X> opt;
  45         static_assert(noexcept(opt.reset()) == true, "");
  46         assert(X::dtor_called == false);
  47         opt.reset();
  48         assert(X::dtor_called == false);
  49         assert(static_cast<bool>(opt) == false);
  50     }
  51     assert(X::dtor_called == false); // TRANSITION, Clang/C2 VSO#239997
  52     {
  53         optional<X> opt(X{});
  54         X::dtor_called = false;
  55         opt.reset();
  56         assert(X::dtor_called == true);
  57         assert(static_cast<bool>(opt) == false);
  58         X::dtor_called = false;
  59     }
  60     assert(X::dtor_called == false); // TRANSITION, Clang/C2 VSO#239997
  61 }