63 lines
1.5 KiB
C++
63 lines
1.5 KiB
C++
//===----------------------------------------------------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is dual licensed under the MIT and the University of Illinois Open
|
|
// Source Licenses. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// UNSUPPORTED: c++98, c++03, c++11
|
|
// <optional>
|
|
|
|
// optional<T>& operator=(nullopt_t) noexcept;
|
|
|
|
#include <experimental/optional>
|
|
#include <type_traits>
|
|
#include <cassert>
|
|
|
|
using std::experimental::optional;
|
|
using std::experimental::nullopt_t;
|
|
using std::experimental::nullopt;
|
|
|
|
struct X
|
|
{
|
|
static bool dtor_called;
|
|
~X() {dtor_called = true;}
|
|
};
|
|
|
|
bool X::dtor_called = false;
|
|
|
|
int main()
|
|
{
|
|
{
|
|
optional<int> opt;
|
|
static_assert(noexcept(opt = nullopt) == true, "");
|
|
opt = nullopt;
|
|
assert(static_cast<bool>(opt) == false);
|
|
}
|
|
{
|
|
optional<int> opt(3);
|
|
opt = nullopt;
|
|
assert(static_cast<bool>(opt) == false);
|
|
}
|
|
{
|
|
optional<X> opt;
|
|
static_assert(noexcept(opt = nullopt) == true, "");
|
|
assert(X::dtor_called == false);
|
|
opt = nullopt;
|
|
assert(X::dtor_called == false);
|
|
assert(static_cast<bool>(opt) == false);
|
|
}
|
|
{
|
|
X x;
|
|
{
|
|
optional<X> opt(x);
|
|
assert(X::dtor_called == false);
|
|
opt = nullopt;
|
|
assert(X::dtor_called == true);
|
|
assert(static_cast<bool>(opt) == false);
|
|
}
|
|
}
|
|
}
|