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// unique_ptr implementation -*- C++ -*-

// Copyright (C) 2008-2012 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/debug.h>

#include <type_traits>

#include <utility>

#include <tuple>

namespace std _GLIBCXX_VISIBILITY(default)

{

_GLIBCXX_BEGIN_NAMESPACE_VERSION

  /**

   * @addtogroup pointer_abstractions

   * @{

   */

#if _GLIBCXX_USE_DEPRECATED

  template<typename> class auto_ptr;

#endif

  /// Primary template, default_delete.

  template<typename _Tp>

    struct default_delete

    {

      constexpr default_delete() noexcept = default;

      template<typename _Up, typename = typename

               std::enable_if<std::is_convertible<_Up*, _Tp*>::value>::type>

        default_delete(const default_delete<_Up>&) noexcept { }

      void

      operator()(_Tp* __ptr) const

      {

        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, default_delete.

  template<typename _Tp>

    struct default_delete<_Tp[]>

    {

      constexpr default_delete() noexcept = default;

      void

      operator()(_Tp* __ptr) const

      {

        static_assert(sizeof(_Tp)>0,

                      "can't delete pointer to incomplete type");

        delete [] __ptr;

      }

      template<typename _Up> void operator()(_Up*) const = delete;

    };

  /// 20.7.1.2 unique_ptr for single objects.

  template <typename _Tp, typename _Dp = default_delete<_Tp> >

    class unique_ptr

    {

      // use SFINAE to determine whether _Del::pointer exists

      class _Pointer

      {

        template<typename _Up>

          static typename _Up::pointer __test(typename _Up::pointer*);

        template<typename _Up>

          static _Tp* __test(...);

        typedef typename remove_reference<_Dp>::type _Del;

      public:

        typedef decltype( __test<_Del>(0)) type;

      };

      typedef std::tuple<typename _Pointer::type, _Dp>  __tuple_type;

      __tuple_type                                      _M_t;

    public:

      typedef typename _Pointer::type   pointer;

      typedef _Tp                       element_type;

      typedef _Dp                       deleter_type;

      // Constructors.

      constexpr unique_ptr() noexcept

      : _M_t()

      { static_assert(!std::is_pointer<deleter_type>::value,

                     "constructed with null function pointer deleter"); }

      explicit

      unique_ptr(pointer __p) noexcept

      : _M_t(__p, deleter_type())

      { static_assert(!std::is_pointer<deleter_type>::value,

                     "constructed with null function pointer deleter"); }

      unique_ptr(pointer __p,

          typename std::conditional<std::is_reference<deleter_type>::value,

            deleter_type, const deleter_type&>::type __d) noexcept

      : _M_t(__p, __d) { }

      unique_ptr(pointer __p,

          typename std::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"); }

      constexpr unique_ptr(nullptr_t) noexcept

      : _M_t()

      { static_assert(!std::is_pointer<deleter_type>::value,

                     "constructed with null function pointer deleter"); }

      // Move constructors.

      unique_ptr(unique_ptr&& __u) noexcept

      : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }

      template<typename _Up, typename _Ep, typename = typename

        std::enable_if

          <std::is_convertible<typename unique_ptr<_Up, _Ep>::pointer,

                               pointer>::value

           && !std::is_array<_Up>::value

           && ((std::is_reference<_Dp>::value

                && std::is_same<_Ep, _Dp>::value)

               || (!std::is_reference<_Dp>::value

                   && std::is_convertible<_Ep, _Dp>::value))>

             ::type>

        unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept

        : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))

        { }

#if _GLIBCXX_USE_DEPRECATED

      template<typename _Up, typename = typename

        std::enable_if<std::is_convertible<_Up*, _Tp*>::value

                       && std::is_same<_Dp,

                                       default_delete<_Tp>>::value>::type>

        unique_ptr(auto_ptr<_Up>&& __u) noexcept;

#endif

      // Destructor.

      ~unique_ptr() noexcept

      {

        auto& __ptr = std::get<0>(_M_t);

        if (__ptr != nullptr)

          get_deleter()(__ptr);

        __ptr = pointer();

      }

      // Assignment.

      unique_ptr&

      operator=(unique_ptr&& __u) noexcept

      {

        reset(__u.release());

        get_deleter() = std::forward<deleter_type>(__u.get_deleter());

        return *this;

      }

      template<typename _Up, typename _Ep, typename = typename

        std::enable_if

          <std::is_convertible<typename unique_ptr<_Up, _Ep>::pointer,

                               pointer>::value

           && !std::is_array<_Up>::value>::type>

        unique_ptr&

        operator=(unique_ptr<_Up, _Ep>&& __u) noexcept

        {

          reset(__u.release());

          get_deleter() = std::forward<_Ep>(__u.get_deleter());

          return *this;

        }

      unique_ptr&

      operator=(nullptr_t) noexcept

      {

        reset();

        return *this;

      }

      // Observers.

      typename std::add_lvalue_reference<element_type>::type

      operator*() const

      {

        _GLIBCXX_DEBUG_ASSERT(get() != pointer());

        return *get();

      }

      pointer

      operator->() const noexcept

      {

        _GLIBCXX_DEBUG_ASSERT(get() != pointer());

        return get();

      }

      pointer

      get() const noexcept

      { return std::get<0>(_M_t); }

      deleter_type&

      get_deleter() noexcept

      { return std::get<1>(_M_t); }

      const deleter_type&

      get_deleter() const noexcept

      { return std::get<1>(_M_t); }

      explicit operator bool() const noexcept

      { return get() == pointer() ? false : true; }

      // Modifiers.

      pointer

      release() noexcept

      {

        pointer __p = get();

        std::get<0>(_M_t) = pointer();

        return __p;

      }

      void

      reset(pointer __p = pointer()) noexcept

      {

        using std::swap;

        swap(std::get<0>(_M_t), __p);

        if (__p != pointer())

          get_deleter()(__p);

      }

      void

      swap(unique_ptr& __u) noexcept

      {

        using std::swap;

        swap(_M_t, __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>

    {

      typedef std::tuple<_Tp*, _Dp>     __tuple_type;

      __tuple_type                      _M_t;

    public:

      typedef _Tp*                      pointer;

      typedef _Tp                       element_type;

      typedef _Dp                       deleter_type;

      // Constructors.

      constexpr unique_ptr() noexcept

      : _M_t()

      { static_assert(!std::is_pointer<deleter_type>::value,

                     "constructed with null function pointer deleter"); }

      explicit

      unique_ptr(pointer __p) noexcept

      : _M_t(__p, deleter_type())

      { static_assert(!std::is_pointer<deleter_type>::value,

                     "constructed with null function pointer deleter"); }

      unique_ptr(pointer __p,

          typename std::conditional<std::is_reference<deleter_type>::value,

              deleter_type, const deleter_type&>::type __d) noexcept

      : _M_t(__p, __d) { }

      unique_ptr(pointer __p, typename

                 std::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"); }

      constexpr unique_ptr(nullptr_t) noexcept

      : _M_t()

      { static_assert(!std::is_pointer<deleter_type>::value,

                     "constructed with null function pointer deleter"); }

      // Move constructors.

      unique_ptr(unique_ptr&& __u) noexcept

      : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }

      template<typename _Up, typename _Ep>

        unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept

        : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))

        { }

      // Destructor.

      ~unique_ptr()

      {

        auto& __ptr = std::get<0>(_M_t);

        if (__ptr != nullptr)

          get_deleter()(__ptr);

        __ptr = pointer();

      }

      // Assignment.

      unique_ptr&

      operator=(unique_ptr&& __u) noexcept

      {

        reset(__u.release());

        get_deleter() = std::forward<deleter_type>(__u.get_deleter());

        return *this;

      }

      template<typename _Up, typename _Ep>

        unique_ptr&

        operator=(unique_ptr<_Up, _Ep>&& __u) noexcept

        {

          reset(__u.release());

          get_deleter() = std::forward<_Ep>(__u.get_deleter());

          return *this;

        }

      unique_ptr&

      operator=(nullptr_t) noexcept

      {

        reset();

        return *this;

      }

      // Observers.

      typename std::add_lvalue_reference<element_type>::type

      operator[](size_t __i) const

      {

        _GLIBCXX_DEBUG_ASSERT(get() != pointer());

        return get()[__i];

      }

      pointer

      get() const noexcept

      { return std::get<0>(_M_t); }

      deleter_type&

      get_deleter() noexcept

      { return std::get<1>(_M_t); }

      const deleter_type&

      get_deleter() const noexcept

      { return std::get<1>(_M_t); }

      explicit operator bool() const noexcept

      { return get() == pointer() ? false : true; }

      // Modifiers.

      pointer

      release() noexcept

      {

        pointer __p = get();

        std::get<0>(_M_t) = pointer();

        return __p;

      }

      void

      reset(pointer __p = pointer()) noexcept

      {

        using std::swap;

        swap(std::get<0>(_M_t), __p);

        if (__p != nullptr)

          get_deleter()(__p);

      }

      void

      reset(nullptr_t) noexcept

      {

        pointer __p = get();

        std::get<0>(_M_t) = pointer();

        if (__p != nullptr)

          get_deleter()(__p);

      }

      // DR 821.

      template<typename _Up>

        void reset(_Up) = delete;

      void

      swap(unique_ptr& __u) noexcept

      {

        using std::swap;

        swap(_M_t, __u._M_t);

      }

      // Disable copy from lvalue.

      unique_ptr(const unique_ptr&) = delete;

      unique_ptr& operator=(const unique_ptr&) = delete;

      // Disable construction from convertible pointer types.

      // (N2315 - 20.7.1.3.1)

      template<typename _Up>

        unique_ptr(_Up*, typename

                   std::conditional<std::is_reference<deleter_type>::value,

                   deleter_type, const deleter_type&>::type,

                   typename std::enable_if<std::is_convertible<_Up*,

                   pointer>::value>::type* = 0) = delete;

      template<typename _Up>

        unique_ptr(_Up*, typename std::remove_reference<deleter_type>::type&&,

                   typename std::enable_if<std::is_convertible<_Up*,

                   pointer>::value>::type* = 0) = delete;

      template<typename _Up>

        explicit

        unique_ptr(_Up*, typename std::enable_if<std::is_convertible<_Up*,

                   pointer>::value>::type* = 0) = delete;

    };

  template<typename _Tp, typename _Dp>

    inline void

    swap(unique_ptr<_Tp, _Dp>& __x,

         unique_ptr<_Tp, _Dp>& __y) noexcept

    { __x.swap(__y); }

  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>>

    {

      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());

      }

    };

  // @} group pointer_abstractions

_GLIBCXX_END_NAMESPACE_VERSION

} // namespace

#endif /* _UNIQUE_PTR_H */