diff options
| -rw-r--r-- | libstdc++-v3/include/bits/node_handle.h | 151 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/20_util/variant/exception_safety.cc | 1 |
2 files changed, 114 insertions, 38 deletions
diff --git a/libstdc++-v3/include/bits/node_handle.h b/libstdc++-v3/include/bits/node_handle.h index fc96937..82b7024 100644 --- a/libstdc++-v3/include/bits/node_handle.h +++ b/libstdc++-v3/include/bits/node_handle.h @@ -33,10 +33,10 @@ #pragma GCC system_header -#if __cplusplus > 201402L +#if __cplusplus >= 201703L # define __cpp_lib_node_extract 201606 -#include <optional> +#include <new> #include <bits/alloc_traits.h> #include <bits/ptr_traits.h> @@ -57,7 +57,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION get_allocator() const noexcept { __glibcxx_assert(!this->empty()); - return allocator_type(*_M_alloc); + return allocator_type(_M_alloc._M_alloc); } explicit operator bool() const noexcept { return _M_ptr != nullptr; } @@ -65,76 +65,151 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION [[nodiscard]] bool empty() const noexcept { return _M_ptr == nullptr; } protected: - constexpr _Node_handle_common() noexcept : _M_ptr(), _M_alloc() {} + constexpr _Node_handle_common() noexcept : _M_ptr() { } - ~_Node_handle_common() { _M_destroy(); } + ~_Node_handle_common() + { + if (!empty()) + _M_reset(); + } _Node_handle_common(_Node_handle_common&& __nh) noexcept - : _M_ptr(__nh._M_ptr), _M_alloc(std::move(__nh._M_alloc)) + : _M_ptr(__nh._M_ptr) { - __nh._M_ptr = nullptr; - __nh._M_alloc = nullopt; + if (_M_ptr) + _M_move(std::move(__nh)); } _Node_handle_common& operator=(_Node_handle_common&& __nh) noexcept { - _M_destroy(); - _M_ptr = __nh._M_ptr; - if constexpr (is_move_assignable_v<_NodeAlloc>) + if (empty()) { - if (_AllocTraits::propagate_on_container_move_assignment::value - || !this->_M_alloc) - this->_M_alloc = std::move(__nh._M_alloc); - else - { - __glibcxx_assert(this->_M_alloc == __nh._M_alloc); - } + if (!__nh.empty()) + _M_move(std::move(__nh)); } + else if (__nh.empty()) + _M_reset(); else { - __glibcxx_assert(_M_alloc); + // Free the current node before replacing the allocator. + _AllocTraits::destroy(*_M_alloc, _M_ptr->_M_valptr()); + _AllocTraits::deallocate(*_M_alloc, _M_ptr, 1); + + _M_alloc = __nh._M_alloc.release(); // assigns if POCMA + _M_ptr = __nh._M_ptr; + __nh._M_ptr = nullptr; } - __nh._M_ptr = nullptr; - __nh._M_alloc = nullopt; return *this; } _Node_handle_common(typename _AllocTraits::pointer __ptr, const _NodeAlloc& __alloc) - : _M_ptr(__ptr), _M_alloc(__alloc) { } + : _M_ptr(__ptr), _M_alloc(__alloc) + { + __glibcxx_assert(__ptr != nullptr); + } void _M_swap(_Node_handle_common& __nh) noexcept { - using std::swap; - swap(_M_ptr, __nh._M_ptr); - if (_AllocTraits::propagate_on_container_swap::value - || !_M_alloc || !__nh._M_alloc) - _M_alloc.swap(__nh._M_alloc); + if (empty()) + { + if (!__nh.empty()) + _M_move(std::move(__nh)); + } + else if (__nh.empty()) + __nh._M_move(std::move(*this)); else { - __glibcxx_assert(_M_alloc == __nh._M_alloc); + using std::swap; + swap(_M_ptr, __nh._M_ptr); + _M_alloc.swap(__nh._M_alloc); // swaps if POCS } } private: + // Moves the pointer and allocator from __nh to *this. + // Precondition: empty() && !__nh.empty() + // Postcondition: !empty() && __nh.empty() void - _M_destroy() noexcept + _M_move(_Node_handle_common&& __nh) noexcept { - if (_M_ptr != nullptr) - { - allocator_type __alloc(*_M_alloc); - allocator_traits<allocator_type>::destroy(__alloc, - _M_ptr->_M_valptr()); - _AllocTraits::deallocate(*_M_alloc, _M_ptr, 1); - } + ::new (std::__addressof(_M_alloc)) _NodeAlloc(__nh._M_alloc.release()); + _M_ptr = __nh._M_ptr; + __nh._M_ptr = nullptr; + } + + // Deallocates the node, destroys the allocator. + // Precondition: !empty() + // Postcondition: empty() + void + _M_reset() noexcept + { + _NodeAlloc __alloc = _M_alloc.release(); + _AllocTraits::destroy(__alloc, _M_ptr->_M_valptr()); + _AllocTraits::deallocate(__alloc, _M_ptr, 1); + _M_ptr = nullptr; } protected: - typename _AllocTraits::pointer _M_ptr; + typename _AllocTraits::pointer _M_ptr; + private: - optional<_NodeAlloc> _M_alloc; + // A simplified, non-copyable std::optional<_NodeAlloc>. + // Call release() before destruction iff the allocator member is active. + union _Optional_alloc + { + _Optional_alloc() { } + ~_Optional_alloc() { } + + _Optional_alloc(_Optional_alloc&&) = delete; + _Optional_alloc& operator=(_Optional_alloc&&) = delete; + + _Optional_alloc(const _NodeAlloc& __alloc) noexcept + : _M_alloc(__alloc) + { } + + // Precondition: _M_alloc is the active member of the union. + void + operator=(_NodeAlloc&& __alloc) noexcept + { + using _ATr = _AllocTraits; + if constexpr (_ATr::propagate_on_container_move_assignment::value) + _M_alloc = std::move(__alloc); + else if constexpr (!_AllocTraits::is_always_equal::value) + __glibcxx_assert(_M_alloc == __alloc); + } + + // Precondition: _M_alloc is the active member of both unions. + void + swap(_Optional_alloc& __other) noexcept + { + using std::swap; + if constexpr (_AllocTraits::propagate_on_container_swap::value) + swap(_M_alloc, __other._M_alloc); + else if constexpr (!_AllocTraits::is_always_equal::value) + __glibcxx_assert(_M_alloc == __other._M_alloc); + } + + // Precondition: _M_alloc is the active member of the union. + _NodeAlloc& operator*() noexcept { return _M_alloc; } + + // Precondition: _M_alloc is the active member of the union. + _NodeAlloc release() noexcept + { + _NodeAlloc __tmp = std::move(_M_alloc); + _M_alloc.~_NodeAlloc(); + return __tmp; + } + + struct _Empty { }; + + [[__no_unique_address__]] _Empty _M_empty; + [[__no_unique_address__]] _NodeAlloc _M_alloc; + }; + + [[__no_unique_address__]] _Optional_alloc _M_alloc; template<typename _Key2, typename _Value2, typename _KeyOfValue, typename _Compare, typename _ValueAlloc> diff --git a/libstdc++-v3/testsuite/20_util/variant/exception_safety.cc b/libstdc++-v3/testsuite/20_util/variant/exception_safety.cc index 019b4e4..c96b921 100644 --- a/libstdc++-v3/testsuite/20_util/variant/exception_safety.cc +++ b/libstdc++-v3/testsuite/20_util/variant/exception_safety.cc @@ -25,6 +25,7 @@ #include <memory> #include <functional> #include <any> +#include <optional> #include <testsuite_hooks.h> void |