Edit: unique_ptr.h
// unique_ptr implementation -*- C++ -*- // Copyright (C) 2008-2018 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // <http://www.gnu.org/licenses/>. /** @file bits/unique_ptr.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{memory} */ #ifndef _UNIQUE_PTR_H #define _UNIQUE_PTR_H 1 #include <bits/c++config.h> #include <debug/assertions.h> #include <type_traits> #include <utility> #include <tuple> #include <bits/stl_function.h> #include <bits/functional_hash.h> namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION /** * @addtogroup pointer_abstractions * @{ */ #if _GLIBCXX_USE_DEPRECATED #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wdeprecated-declarations" template<typename> class auto_ptr; #pragma GCC diagnostic pop #endif /// Primary template of default_delete, used by unique_ptr template<typename _Tp> struct default_delete { /// Default constructor constexpr default_delete() noexcept = default; /** @brief Converting constructor. * * Allows conversion from a deleter for arrays of another type, @p _Up, * only if @p _Up* is convertible to @p _Tp*. */ template<typename _Up, typename = typename enable_if<is_convertible<_Up*, _Tp*>::value>::type> default_delete(const default_delete<_Up>&) noexcept { } /// Calls @c delete @p __ptr void operator()(_Tp* __ptr) const { static_assert(!is_void<_Tp>::value, "can't delete pointer to incomplete type"); static_assert(sizeof(_Tp)>0, "can't delete pointer to incomplete type"); delete __ptr; } }; // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 740 - omit specialization for array objects with a compile time length /// Specialization for arrays, default_delete. template<typename _Tp> struct default_delete<_Tp[]> { public: /// Default constructor constexpr default_delete() noexcept = default; /** @brief Converting constructor. * * Allows conversion from a deleter for arrays of another type, such as * a const-qualified version of @p _Tp. * * Conversions from types derived from @c _Tp are not allowed because * it is unsafe to @c delete[] an array of derived types through a * pointer to the base type. */ template<typename _Up, typename = typename enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value>::type> default_delete(const default_delete<_Up[]>&) noexcept { } /// Calls @c delete[] @p __ptr template<typename _Up> typename enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value>::type operator()(_Up* __ptr) const { static_assert(sizeof(_Tp)>0, "can't delete pointer to incomplete type"); delete [] __ptr; } }; template <typename _Tp, typename _Dp> class __uniq_ptr_impl { template <typename _Up, typename _Ep, typename = void> struct _Ptr { using type = _Up*; }; template <typename _Up, typename _Ep> struct _Ptr<_Up, _Ep, __void_t<typename remove_reference<_Ep>::type::pointer>> { using type = typename remove_reference<_Ep>::type::pointer; }; public: using _DeleterConstraint = enable_if< __and_<__not_<is_pointer<_Dp>>, is_default_constructible<_Dp>>::value>; using pointer = typename _Ptr<_Tp, _Dp>::type; __uniq_ptr_impl() = default; __uniq_ptr_impl(pointer __p) : _M_t() { _M_ptr() = __p; } template<typename _Del> __uniq_ptr_impl(pointer __p, _Del&& __d) : _M_t(__p, std::forward<_Del>(__d)) { } pointer& _M_ptr() { return std::get<0>(_M_t); } pointer _M_ptr() const { return std::get<0>(_M_t); } _Dp& _M_deleter() { return std::get<1>(_M_t); } const _Dp& _M_deleter() const { return std::get<1>(_M_t); } void swap(__uniq_ptr_impl& __rhs) noexcept { using std::swap; swap(this->_M_ptr(), __rhs._M_ptr()); swap(this->_M_deleter(), __rhs._M_deleter()); } private: tuple<pointer, _Dp> _M_t; }; /// 20.7.1.2 unique_ptr for single objects. template <typename _Tp, typename _Dp = default_delete<_Tp>> class unique_ptr { template <class _Up> using _DeleterConstraint = typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type; __uniq_ptr_impl<_Tp, _Dp> _M_t; public: using pointer = typename __uniq_ptr_impl<_Tp, _Dp>::pointer; using element_type = _Tp; using deleter_type = _Dp; // helper template for detecting a safe conversion from another // unique_ptr template<typename _Up, typename _Ep> using __safe_conversion_up = __and_< is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>, __not_<is_array<_Up>> >; // Constructors. /// Default constructor, creates a unique_ptr that owns nothing. template <typename _Up = _Dp, typename = _DeleterConstraint<_Up>> constexpr unique_ptr() noexcept : _M_t() { } /** Takes ownership of a pointer. * * @param __p A pointer to an object of @c element_type * * The deleter will be value-initialized. */ template <typename _Up = _Dp, typename = _DeleterConstraint<_Up>> explicit unique_ptr(pointer __p) noexcept : _M_t(__p) { } /** Takes ownership of a pointer. * * @param __p A pointer to an object of @c element_type * @param __d A reference to a deleter. * * The deleter will be initialized with @p __d */ unique_ptr(pointer __p, typename conditional<is_reference<deleter_type>::value, deleter_type, const deleter_type&>::type __d) noexcept : _M_t(__p, __d) { } /** Takes ownership of a pointer. * * @param __p A pointer to an object of @c element_type * @param __d An rvalue reference to a deleter. * * The deleter will be initialized with @p std::move(__d) */ unique_ptr(pointer __p, typename remove_reference<deleter_type>::type&& __d) noexcept : _M_t(std::move(__p), std::move(__d)) { static_assert(!std::is_reference<deleter_type>::value, "rvalue deleter bound to reference"); } /// Creates a unique_ptr that owns nothing. template <typename _Up = _Dp, typename = _DeleterConstraint<_Up>> constexpr unique_ptr(nullptr_t) noexcept : _M_t() { } // Move constructors. /// Move constructor. unique_ptr(unique_ptr&& __u) noexcept : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { } /** @brief Converting constructor from another type * * Requires that the pointer owned by @p __u is convertible to the * type of pointer owned by this object, @p __u does not own an array, * and @p __u has a compatible deleter type. */ template<typename _Up, typename _Ep, typename = _Require< __safe_conversion_up<_Up, _Ep>, typename conditional<is_reference<_Dp>::value, is_same<_Ep, _Dp>, is_convertible<_Ep, _Dp>>::type>> unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter())) { } #if _GLIBCXX_USE_DEPRECATED #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wdeprecated-declarations" /// Converting constructor from @c auto_ptr template<typename _Up, typename = _Require< is_convertible<_Up*, _Tp*>, is_same<_Dp, default_delete<_Tp>>>> unique_ptr(auto_ptr<_Up>&& __u) noexcept; #pragma GCC diagnostic pop #endif /// Destructor, invokes the deleter if the stored pointer is not null. ~unique_ptr() noexcept { auto& __ptr = _M_t._M_ptr(); if (__ptr != nullptr) get_deleter()(__ptr); __ptr = pointer(); } // Assignment. /** @brief Move assignment operator. * * @param __u The object to transfer ownership from. * * Invokes the deleter first if this object owns a pointer. */ unique_ptr& operator=(unique_ptr&& __u) noexcept { reset(__u.release()); get_deleter() = std::forward<deleter_type>(__u.get_deleter()); return *this; } /** @brief Assignment from another type. * * @param __u The object to transfer ownership from, which owns a * convertible pointer to a non-array object. * * Invokes the deleter first if this object owns a pointer. */ template<typename _Up, typename _Ep> typename enable_if< __and_< __safe_conversion_up<_Up, _Ep>, is_assignable<deleter_type&, _Ep&&> >::value, unique_ptr&>::type operator=(unique_ptr<_Up, _Ep>&& __u) noexcept { reset(__u.release()); get_deleter() = std::forward<_Ep>(__u.get_deleter()); return *this; } /// Reset the %unique_ptr to empty, invoking the deleter if necessary. unique_ptr& operator=(nullptr_t) noexcept { reset(); return *this; } // Observers. /// Dereference the stored pointer. typename add_lvalue_reference<element_type>::type operator*() const { __glibcxx_assert(get() != pointer()); return *get(); } /// Return the stored pointer. pointer operator->() const noexcept { _GLIBCXX_DEBUG_PEDASSERT(get() != pointer()); return get(); } /// Return the stored pointer. pointer get() const noexcept { return _M_t._M_ptr(); } /// Return a reference to the stored deleter. deleter_type& get_deleter() noexcept { return _M_t._M_deleter(); } /// Return a reference to the stored deleter. const deleter_type& get_deleter() const noexcept { return _M_t._M_deleter(); } /// Return @c true if the stored pointer is not null. explicit operator bool() const noexcept { return get() == pointer() ? false : true; } // Modifiers. /// Release ownership of any stored pointer. pointer release() noexcept { pointer __p = get(); _M_t._M_ptr() = pointer(); return __p; } /** @brief Replace the stored pointer. * * @param __p The new pointer to store. * * The deleter will be invoked if a pointer is already owned. */ void reset(pointer __p = pointer()) noexcept { using std::swap; swap(_M_t._M_ptr(), __p); if (__p != pointer()) get_deleter()(__p); } /// Exchange the pointer and deleter with another object. void swap(unique_ptr& __u) noexcept { static_assert(__is_swappable<_Dp>::value, "deleter must be swappable"); _M_t.swap(__u._M_t); } // Disable copy from lvalue. unique_ptr(const unique_ptr&) = delete; unique_ptr& operator=(const unique_ptr&) = delete; }; /// 20.7.1.3 unique_ptr for array objects with a runtime length // [unique.ptr.runtime] // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 740 - omit specialization for array objects with a compile time length template<typename _Tp, typename _Dp> class unique_ptr<_Tp[], _Dp> { template <typename _Up> using _DeleterConstraint = typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type; __uniq_ptr_impl<_Tp, _Dp> _M_t; template<typename _Up> using __remove_cv = typename remove_cv<_Up>::type; // like is_base_of<_Tp, _Up> but false if unqualified types are the same template<typename _Up> using __is_derived_Tp = __and_< is_base_of<_Tp, _Up>, __not_<is_same<__remove_cv<_Tp>, __remove_cv<_Up>>> >; public: using pointer = typename __uniq_ptr_impl<_Tp, _Dp>::pointer; using element_type = _Tp; using deleter_type = _Dp; // helper template for detecting a safe conversion from another // unique_ptr template<typename _Up, typename _Ep, typename _UPtr = unique_ptr<_Up, _Ep>, typename _UP_pointer = typename _UPtr::pointer, typename _UP_element_type = typename _UPtr::element_type> using __safe_conversion_up = __and_< is_array<_Up>, is_same<pointer, element_type*>, is_same<_UP_pointer, _UP_element_type*>, is_convertible<_UP_element_type(*)[], element_type(*)[]> >; // helper template for detecting a safe conversion from a raw pointer template<typename _Up> using __safe_conversion_raw = __and_< __or_<__or_<is_same<_Up, pointer>, is_same<_Up, nullptr_t>>, __and_<is_pointer<_Up>, is_same<pointer, element_type*>, is_convertible< typename remove_pointer<_Up>::type(*)[], element_type(*)[]> > > >; // Constructors. /// Default constructor, creates a unique_ptr that owns nothing. template <typename _Up = _Dp, typename = _DeleterConstraint<_Up>> constexpr unique_ptr() noexcept : _M_t() { } /** Takes ownership of a pointer. * * @param __p A pointer to an array of a type safely convertible * to an array of @c element_type * * The deleter will be value-initialized. */ template<typename _Up, typename _Vp = _Dp, typename = _DeleterConstraint<_Vp>, typename = typename enable_if< __safe_conversion_raw<_Up>::value, bool>::type> explicit unique_ptr(_Up __p) noexcept : _M_t(__p) { } /** Takes ownership of a pointer. * * @param __p A pointer to an array of a type safely convertible * to an array of @c element_type * @param __d A reference to a deleter. * * The deleter will be initialized with @p __d */ template<typename _Up, typename = typename enable_if< __safe_conversion_raw<_Up>::value, bool>::type> unique_ptr(_Up __p, typename conditional<is_reference<deleter_type>::value, deleter_type, const deleter_type&>::type __d) noexcept : _M_t(__p, __d) { } /** Takes ownership of a pointer. * * @param __p A pointer to an array of a type safely convertible * to an array of @c element_type * @param __d A reference to a deleter. * * The deleter will be initialized with @p std::move(__d) */ template<typename _Up, typename = typename enable_if< __safe_conversion_raw<_Up>::value, bool>::type> unique_ptr(_Up __p, typename remove_reference<deleter_type>::type&& __d) noexcept : _M_t(std::move(__p), std::move(__d)) { static_assert(!is_reference<deleter_type>::value, "rvalue deleter bound to reference"); } /// Move constructor. unique_ptr(unique_ptr&& __u) noexcept : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { } /// Creates a unique_ptr that owns nothing. template <typename _Up = _Dp, typename = _DeleterConstraint<_Up>> constexpr unique_ptr(nullptr_t) noexcept : _M_t() { } template<typename _Up, typename _Ep, typename = _Require< __safe_conversion_up<_Up, _Ep>, typename conditional<is_reference<_Dp>::value, is_same<_Ep, _Dp>, is_convertible<_Ep, _Dp>>::type>> unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter())) { } /// Destructor, invokes the deleter if the stored pointer is not null. ~unique_ptr() { auto& __ptr = _M_t._M_ptr(); if (__ptr != nullptr) get_deleter()(__ptr); __ptr = pointer(); } // Assignment. /** @brief Move assignment operator. * * @param __u The object to transfer ownership from. * * Invokes the deleter first if this object owns a pointer. */ unique_ptr& operator=(unique_ptr&& __u) noexcept { reset(__u.release()); get_deleter() = std::forward<deleter_type>(__u.get_deleter()); return *this; } /** @brief Assignment from another type. * * @param __u The object to transfer ownership from, which owns a * convertible pointer to an array object. * * Invokes the deleter first if this object owns a pointer. */ template<typename _Up, typename _Ep> typename enable_if<__and_<__safe_conversion_up<_Up, _Ep>, is_assignable<deleter_type&, _Ep&&> >::value, unique_ptr&>::type operator=(unique_ptr<_Up, _Ep>&& __u) noexcept { reset(__u.release()); get_deleter() = std::forward<_Ep>(__u.get_deleter()); return *this; } /// Reset the %unique_ptr to empty, invoking the deleter if necessary. unique_ptr& operator=(nullptr_t) noexcept { reset(); return *this; } // Observers. /// Access an element of owned array. typename std::add_lvalue_reference<element_type>::type operator[](size_t __i) const { __glibcxx_assert(get() != pointer()); return get()[__i]; } /// Return the stored pointer. pointer get() const noexcept { return _M_t._M_ptr(); } /// Return a reference to the stored deleter. deleter_type& get_deleter() noexcept { return _M_t._M_deleter(); } /// Return a reference to the stored deleter. const deleter_type& get_deleter() const noexcept { return _M_t._M_deleter(); } /// Return @c true if the stored pointer is not null. explicit operator bool() const noexcept { return get() == pointer() ? false : true; } // Modifiers. /// Release ownership of any stored pointer. pointer release() noexcept { pointer __p = get(); _M_t._M_ptr() = pointer(); return __p; } /** @brief Replace the stored pointer. * * @param __p The new pointer to store. * * The deleter will be invoked if a pointer is already owned. */ template <typename _Up, typename = _Require< __or_<is_same<_Up, pointer>, __and_<is_same<pointer, element_type*>, is_pointer<_Up>, is_convertible< typename remove_pointer<_Up>::type(*)[], element_type(*)[] > > > >> void reset(_Up __p) noexcept { pointer __ptr = __p; using std::swap; swap(_M_t._M_ptr(), __ptr); if (__ptr != nullptr) get_deleter()(__ptr); } void reset(nullptr_t = nullptr) noexcept { reset(pointer()); } /// Exchange the pointer and deleter with another object. void swap(unique_ptr& __u) noexcept { static_assert(__is_swappable<_Dp>::value, "deleter must be swappable"); _M_t.swap(__u._M_t); } // Disable copy from lvalue. unique_ptr(const unique_ptr&) = delete; unique_ptr& operator=(const unique_ptr&) = delete; }; template<typename _Tp, typename _Dp> inline #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 // Constrained free swap overload, see p0185r1 typename enable_if<__is_swappable<_Dp>::value>::type #else void #endif swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) noexcept { __x.swap(__y); } #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 template<typename _Tp, typename _Dp> typename enable_if<!__is_swappable<_Dp>::value>::type swap(unique_ptr<_Tp, _Dp>&, unique_ptr<_Tp, _Dp>&) = delete; #endif template<typename _Tp, typename _Dp, typename _Up, typename _Ep> inline bool operator==(const unique_ptr<_Tp, _Dp>& __x, const unique_ptr<_Up, _Ep>& __y) { return __x.get() == __y.get(); } template<typename _Tp, typename _Dp> inline bool operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept { return !__x; } template<typename _Tp, typename _Dp> inline bool operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept { return !__x; } template<typename _Tp, typename _Dp, typename _Up, typename _Ep> inline bool operator!=(const unique_ptr<_Tp, _Dp>& __x, const unique_ptr<_Up, _Ep>& __y) { return __x.get() != __y.get(); } template<typename _Tp, typename _Dp> inline bool operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept { return (bool)__x; } template<typename _Tp, typename _Dp> inline bool operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept { return (bool)__x; } template<typename _Tp, typename _Dp, typename _Up, typename _Ep> inline bool operator<(const unique_ptr<_Tp, _Dp>& __x, const unique_ptr<_Up, _Ep>& __y) { typedef typename std::common_type<typename unique_ptr<_Tp, _Dp>::pointer, typename unique_ptr<_Up, _Ep>::pointer>::type _CT; return std::less<_CT>()(__x.get(), __y.get()); } template<typename _Tp, typename _Dp> inline bool operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(), nullptr); } template<typename _Tp, typename _Dp> inline bool operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr, __x.get()); } template<typename _Tp, typename _Dp, typename _Up, typename _Ep> inline bool operator<=(const unique_ptr<_Tp, _Dp>& __x, const unique_ptr<_Up, _Ep>& __y) { return !(__y < __x); } template<typename _Tp, typename _Dp> inline bool operator<=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) { return !(nullptr < __x); } template<typename _Tp, typename _Dp> inline bool operator<=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) { return !(__x < nullptr); } template<typename _Tp, typename _Dp, typename _Up, typename _Ep> inline bool operator>(const unique_ptr<_Tp, _Dp>& __x, const unique_ptr<_Up, _Ep>& __y) { return (__y < __x); } template<typename _Tp, typename _Dp> inline bool operator>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr, __x.get()); } template<typename _Tp, typename _Dp> inline bool operator>(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(), nullptr); } template<typename _Tp, typename _Dp, typename _Up, typename _Ep> inline bool operator>=(const unique_ptr<_Tp, _Dp>& __x, const unique_ptr<_Up, _Ep>& __y) { return !(__x < __y); } template<typename _Tp, typename _Dp> inline bool operator>=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) { return !(__x < nullptr); } template<typename _Tp, typename _Dp> inline bool operator>=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) { return !(nullptr < __x); } /// std::hash specialization for unique_ptr. template<typename _Tp, typename _Dp> struct hash<unique_ptr<_Tp, _Dp>> : public __hash_base<size_t, unique_ptr<_Tp, _Dp>>, private __poison_hash<typename unique_ptr<_Tp, _Dp>::pointer> { size_t operator()(const unique_ptr<_Tp, _Dp>& __u) const noexcept { typedef unique_ptr<_Tp, _Dp> _UP; return std::hash<typename _UP::pointer>()(__u.get()); } }; #if __cplusplus > 201103L #define __cpp_lib_make_unique 201304 template<typename _Tp> struct _MakeUniq { typedef unique_ptr<_Tp> __single_object; }; template<typename _Tp> struct _MakeUniq<_Tp[]> { typedef unique_ptr<_Tp[]> __array; }; template<typename _Tp, size_t _Bound> struct _MakeUniq<_Tp[_Bound]> { struct __invalid_type { }; }; /// std::make_unique for single objects template<typename _Tp, typename... _Args> inline typename _MakeUniq<_Tp>::__single_object make_unique(_Args&&... __args) { return unique_ptr<_Tp>(new _Tp(std::forward<_Args>(__args)...)); } /// std::make_unique for arrays of unknown bound template<typename _Tp> inline typename _MakeUniq<_Tp>::__array make_unique(size_t __num) { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__num]()); } /// Disable std::make_unique for arrays of known bound template<typename _Tp, typename... _Args> inline typename _MakeUniq<_Tp>::__invalid_type make_unique(_Args&&...) = delete; #endif // @} group pointer_abstractions _GLIBCXX_END_NAMESPACE_VERSION } // namespace #endif /* _UNIQUE_PTR_H */
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