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