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35ce4859dd
Summary: Adapt implementation of Library Fundamentals TS optional into an implementation of N4606 optional. - Update relational operators per http://wg21.link/P0307 - Update to requirements of http://wg21.link/P0032 - Extension: Implement trivial copy/move construction/assignment for `optional<T>` when `T` is trivially copyable. Audit P/Rs for optional LWG issues: - 2756 "C++ WP optional<T> should 'forward' T's implicit conversions" Implemented, which also resolves 2753 "Optional's constructors and assignments need constraints" (modulo my refusal to explicitly delete the move operations, which is a design error that I'm working on correcting in the 2756 P/R). - 2736 "nullopt_t insufficiently constrained" Already conforming. I've added a test ensuring that `nullopt_t` is not copy-initializable from an empty braced-init-list, which I believe is the root intent of the issue, to avoid regression. - 2740 "constexpr optional<T>::operator->" Already conforming. - 2746 "Inconsistency between requirements for emplace between optional and variant" No P/R, but note that the author's '"suggested resolution" is already implemented. - 2748 "swappable traits for optionals" Already conforming. - 2753 "Optional's constructors and assignments need constraints" Implemented. Most of the work for this patch was done by Casey Carter @ Microsoft. Thank you Casey! Reviewers: mclow.lists, CaseyCarter, EricWF Differential Revision: https://reviews.llvm.org/D22741 git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283980 91177308-0d34-0410-b5e6-96231b3b80d8
51 lines
1.8 KiB
C++
51 lines
1.8 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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// UNSUPPORTED: c++98, c++03, c++11, c++14
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// <optional>
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// T shall be an object type and shall satisfy the requirements of Destructible
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#include <optional>
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using std::optional;
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struct X
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{
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private:
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~X() {}
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};
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int main()
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{
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using std::optional;
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{
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// expected-error@optional:* 2 {{static_assert failed "instantiation of optional with a reference type is ill-formed}}
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optional<int&> opt1;
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optional<int&&> opt2;
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}
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{
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// expected-error@optional:* {{static_assert failed "instantiation of optional with a non-destructible type is ill-formed"}}
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optional<X> opt3;
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}
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{
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// expected-error@optional:* {{static_assert failed "instantiation of optional with a non-object type is undefined behavior"}}
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// expected-error@optional:* {{static_assert failed "instantiation of optional with a non-destructible type is ill-formed}}
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optional<void()> opt4;
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}
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{
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// expected-error@optional:* {{static_assert failed "instantiation of optional with a non-object type is undefined behavior"}}
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// expected-error@optional:* {{static_assert failed "instantiation of optional with a non-destructible type is ill-formed}}
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// expected-error@optional:* 1+ {{cannot form a reference to 'void'}}
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optional<const void> opt4;
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}
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// FIXME these are garbage diagnostics that Clang should not produce
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// expected-error@optional:* 0+ {{is not a base class}}
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}
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