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//===----------------------------------------------------------------------===//
//
// 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.
//
//===----------------------------------------------------------------------===//
// <optional>
// optional<T>& operator=(nullopt_t) noexcept;
#include <experimental/optional>
#include <type_traits>
#include <cassert>
#if _LIBCPP_STD_VER > 11
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;
#endif // _LIBCPP_STD_VER > 11
int main()
{
#if _LIBCPP_STD_VER > 11
{
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);
}
}
#endif // _LIBCPP_STD_VER > 11
}
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