/build/llvm-toolchain-snapshot-7~svn326551/tools/lldb/source/API/SBTypeEnumMember.cpp

Bug Summary

File:	tools/lldb/source/API/SBTypeEnumMember.cpp
Warning:	line 94, column 5 Potential leak of memory pointed to by field '_M_pi'

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SBTypeEnumMember.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-eagerly-assume -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-7/lib/clang/7.0.0 -D HAVE_ROUND -D LLDB_CONFIGURATION_RELEASE -D LLDB_USE_BUILTIN_DEMANGLER -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-7~svn326551/build-llvm/tools/lldb/source/API -I /build/llvm-toolchain-snapshot-7~svn326551/tools/lldb/source/API -I /build/llvm-toolchain-snapshot-7~svn326551/build-llvm/tools/lldb/include -I /build/llvm-toolchain-snapshot-7~svn326551/tools/lldb/include -I /build/llvm-toolchain-snapshot-7~svn326551/build-llvm/include -I /build/llvm-toolchain-snapshot-7~svn326551/include -I /usr/include/python2.7 -I /build/llvm-toolchain-snapshot-7~svn326551/tools/clang/include -I /build/llvm-toolchain-snapshot-7~svn326551/build-llvm/tools/lldb/../clang/include -I /build/llvm-toolchain-snapshot-7~svn326551/tools/lldb/source/. -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0/backward -internal-isystem /usr/include/clang/7.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-7/lib/clang/7.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -Wno-deprecated-declarations -Wno-unknown-pragmas -Wno-strict-aliasing -Wno-deprecated-register -Wno-vla-extension -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-7~svn326551/build-llvm/tools/lldb/source/API -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-03-02-155150-1477-1 -x c++ /build/llvm-toolchain-snapshot-7~svn326551/tools/lldb/source/API/SBTypeEnumMember.cpp

/build/llvm-toolchain-snapshot-7~svn326551/tools/lldb/source/API/SBTypeEnumMember.cpp

→

1//===-- SBTypeEnumMember.cpp ---------------------------------- -*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9 
10#include "lldb/API/SBTypeEnumMember.h"
11#include "lldb/API/SBDefines.h"
12#include "lldb/API/SBStream.h"
13#include "lldb/API/SBType.h"
14#include "lldb/Symbol/CompilerType.h"
15#include "lldb/Symbol/Type.h"
16#include "lldb/Utility/Stream.h"
17 
18using namespace lldb;
19using namespace lldb_private;
20 
21SBTypeEnumMember::SBTypeEnumMember() : m_opaque_sp() {}
22 
23SBTypeEnumMember::~SBTypeEnumMember() {}
24SBTypeEnumMember::SBTypeEnumMember(
25    const lldb::TypeEnumMemberImplSP &enum_member_sp)
26    : m_opaque_sp(enum_member_sp) {}
27 
28SBTypeEnumMember::SBTypeEnumMember(const SBTypeEnumMember &rhs)
29    : m_opaque_sp() {
30  if (this != &rhs) {
6
←
Taking true branch→
31    if (rhs.IsValid())
7
←
Assuming the condition is true→
8
←
Taking true branch→
32      m_opaque_sp.reset(new TypeEnumMemberImpl(rhs.ref()));
9
←
Calling '__shared_ptr::reset'→
17
←
Returned allocated memory→
33  }
34}
35 
36SBTypeEnumMember &SBTypeEnumMember::operator=(const SBTypeEnumMember &rhs) {
37  if (this != &rhs) {
38    if (rhs.IsValid())
39      m_opaque_sp.reset(new TypeEnumMemberImpl(rhs.ref()));
40  }
41  return *this;
42}
43 
44bool SBTypeEnumMember::IsValid() const { return m_opaque_sp.get(); }
45 
46const char *SBTypeEnumMember::GetName() {
47  if (m_opaque_sp.get())
48    return m_opaque_sp->GetName().GetCString();
49  return NULL__null;
50}
51 
52int64_t SBTypeEnumMember::GetValueAsSigned() {
53  if (m_opaque_sp.get())
54    return m_opaque_sp->GetValueAsSigned();
55  return 0;
56}
57 
58uint64_t SBTypeEnumMember::GetValueAsUnsigned() {
59  if (m_opaque_sp.get())
60    return m_opaque_sp->GetValueAsUnsigned();
61  return 0;
62}
63 
64SBType SBTypeEnumMember::GetType() {
65  SBType sb_type;
66  if (m_opaque_sp.get()) {
67    sb_type.SetSP(m_opaque_sp->GetIntegerType());
68  }
69  return sb_type;
70}
71 
72void SBTypeEnumMember::reset(TypeEnumMemberImpl *type_member_impl) {
73  m_opaque_sp.reset(type_member_impl);
74}
75 
76TypeEnumMemberImpl &SBTypeEnumMember::ref() {
77  if (m_opaque_sp.get() == NULL__null)
78    m_opaque_sp.reset(new TypeEnumMemberImpl());
79  return *m_opaque_sp.get();
80}
81 
82const TypeEnumMemberImpl &SBTypeEnumMember::ref() const {
83  return *m_opaque_sp.get();
84}
85 
86SBTypeEnumMemberList::SBTypeEnumMemberList()
87    : m_opaque_ap(new TypeEnumMemberListImpl()) {}
88 
89SBTypeEnumMemberList::SBTypeEnumMemberList(const SBTypeEnumMemberList &rhs)
90    : m_opaque_ap(new TypeEnumMemberListImpl()) {
91  for (uint32_t i = 0,
2
←
Loop condition is true.  Entering loop body→
92                rhs_size = const_cast<SBTypeEnumMemberList &>(rhs).GetSize();
93       i < rhs_size; i++)
1
Assuming 'i' is < 'rhs_size'→
94    Append(const_cast<SBTypeEnumMemberList &>(rhs).GetTypeEnumMemberAtIndex(i));
3
←
Calling 'SBTypeEnumMemberList::GetTypeEnumMemberAtIndex'→
19
←
Returned allocated memory→
20
←
Potential leak of memory pointed to by field '_M_pi'
95}
96 
97bool SBTypeEnumMemberList::IsValid() { return (m_opaque_ap.get() != NULL__null); }
98 
99SBTypeEnumMemberList &SBTypeEnumMemberList::
100operator=(const SBTypeEnumMemberList &rhs) {
101  if (this != &rhs) {
102    m_opaque_ap.reset(new TypeEnumMemberListImpl());
103    for (uint32_t i = 0,
104                  rhs_size = const_cast<SBTypeEnumMemberList &>(rhs).GetSize();
105         i < rhs_size; i++)
106      Append(
107          const_cast<SBTypeEnumMemberList &>(rhs).GetTypeEnumMemberAtIndex(i));
108  }
109  return *this;
110}
111 
112void SBTypeEnumMemberList::Append(SBTypeEnumMember enum_member) {
113  if (enum_member.IsValid())
114    m_opaque_ap->Append(enum_member.m_opaque_sp);
115}
116 
117SBTypeEnumMember
118SBTypeEnumMemberList::GetTypeEnumMemberAtIndex(uint32_t index) {
119  if (m_opaque_ap.get())
4
←
Taking true branch→
120    return SBTypeEnumMember(m_opaque_ap->GetTypeEnumMemberAtIndex(index));
5
←
Calling copy constructor for 'SBTypeEnumMember'→
18
←
Returning from copy constructor for 'SBTypeEnumMember'→
121  return SBTypeEnumMember();
122}
123 
124uint32_t SBTypeEnumMemberList::GetSize() { return m_opaque_ap->GetSize(); }
125 
126SBTypeEnumMemberList::~SBTypeEnumMemberList() {}
127 
128bool SBTypeEnumMember::GetDescription(
129    lldb::SBStream &description, lldb::DescriptionLevel description_level) {
130  Stream &strm = description.ref();
131 
132  if (m_opaque_sp.get()) {
133    if (m_opaque_sp->GetIntegerType()->GetDescription(strm,
134                                                      description_level)) {
135      strm.Printf(" %s", m_opaque_sp->GetName().GetCString());
136    }
137  } else {
138    strm.PutCString("No value");
139  }
140  return true;
141}

←

/usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0/bits/shared_ptr_base.h

1// shared_ptr and weak_ptr implementation details -*- C++ -*-

3// Copyright (C) 2007-2017 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library.  This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.

11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14// GNU General Public License for more details.

16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.

20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23// <http://www.gnu.org/licenses/>.

25// GCC Note: Based on files from version 1.32.0 of the Boost library.

27//  shared_count.hpp
28//  Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.

30//  shared_ptr.hpp
31//  Copyright (C) 1998, 1999 Greg Colvin and Beman Dawes.
32//  Copyright (C) 2001, 2002, 2003 Peter Dimov

34//  weak_ptr.hpp
35//  Copyright (C) 2001, 2002, 2003 Peter Dimov

37//  enable_shared_from_this.hpp
38//  Copyright (C) 2002 Peter Dimov

40// Distributed under the Boost Software License, Version 1.0. (See
41// accompanying file LICENSE_1_0.txt or copy at
42// http://www.boost.org/LICENSE_1_0.txt)

44/** @file bits/shared_ptr_base.h
*  This is an internal header file, included by other library headers.
*  Do not attempt to use it directly. @headername{memory}
*/

49#ifndef _SHARED_PTR_BASE_H1
50#define _SHARED_PTR_BASE_H1 1

52#if __cpp_rtti199711
53# include <typeinfo>
54#endif
55#include <bits/allocated_ptr.h>
56#include <bits/refwrap.h>
57#include <bits/stl_function.h>
58#include <ext/aligned_buffer.h>

60namespace std _GLIBCXX_VISIBILITY(default)__attribute__ ((__visibility__ ("default")))
61{
62_GLIBCXX_BEGIN_NAMESPACE_VERSION

64#if _GLIBCXX_USE_DEPRECATED1
template<typename> class auto_ptr;
66#endif

/**
 *  @brief  Exception possibly thrown by @c shared_ptr.
 *  @ingroup exceptions
 */
class bad_weak_ptr : public std::exception
{
public:
  virtual char const* what() const noexcept;

  virtual ~bad_weak_ptr() noexcept;
};

// Substitute for bad_weak_ptr object in the case of -fno-exceptions.
inline void
__throw_bad_weak_ptr()
{ _GLIBCXX_THROW_OR_ABORT(bad_weak_ptr())(__builtin_abort()); }

using __gnu_cxx::_Lock_policy;
using __gnu_cxx::__default_lock_policy;
using __gnu_cxx::_S_single;
using __gnu_cxx::_S_mutex;
using __gnu_cxx::_S_atomic;

// Empty helper class except when the template argument is _S_mutex.
template<_Lock_policy _Lp>
  class _Mutex_base
  {
  protected:
    // The atomic policy uses fully-fenced builtins, single doesn't care.
    enum { _S_need_barriers = 0 };
  };

template<>
  class _Mutex_base<_S_mutex>
  : public __gnu_cxx::__mutex
  {
  protected:
    // This policy is used when atomic builtins are not available.
    // The replacement atomic operations might not have the necessary
    // memory barriers.
    enum { _S_need_barriers = 1 };
  };

template<_Lock_policy _Lp = __default_lock_policy>
  class _Sp_counted_base
  : public _Mutex_base<_Lp>
  {
  public:
    _Sp_counted_base() noexcept
    : _M_use_count(1), _M_weak_count(1) { }

    virtual
    ~_Sp_counted_base() noexcept
    { }

    // Called when _M_use_count drops to zero, to release the resources
    // managed by *this.
    virtual void
    _M_dispose() noexcept = 0;

    // Called when _M_weak_count drops to zero.
    virtual void
    _M_destroy() noexcept
    { delete this; }

    virtual void*
    _M_get_deleter(const std::type_info&) noexcept = 0;

    void
    _M_add_ref_copy()
    { __gnu_cxx::__atomic_add_dispatch(&_M_use_count, 1); }

    void
    _M_add_ref_lock();

    bool
    _M_add_ref_lock_nothrow();

    void
    _M_release() noexcept
    {
      // Be race-detector-friendly.  For more info see bits/c++config.
      _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_use_count);
if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, -1) == 1)
 {
          _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_use_count);
   _M_dispose();
   // There must be a memory barrier between dispose() and destroy()
   // to ensure that the effects of dispose() are observed in the
   // thread that runs destroy().
   // See http://gcc.gnu.org/ml/libstdc++/2005-11/msg00136.html
   if (_Mutex_base<_Lp>::_S_need_barriers)
     {
__atomic_thread_fence (__ATOMIC_ACQ_REL4);
     }

          // Be race-detector-friendly.  For more info see bits/c++config.
          _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count);
   if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count,
				       -1) == 1)
            {
              _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count);
       _M_destroy();
            }
 }
    }

    void
    _M_weak_add_ref() noexcept
    { __gnu_cxx::__atomic_add_dispatch(&_M_weak_count, 1); }

    void
    _M_weak_release() noexcept
    {
      // Be race-detector-friendly. For more info see bits/c++config.
      _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count);
if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count, -1) == 1)
 {
          _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count);
   if (_Mutex_base<_Lp>::_S_need_barriers)
     {
       // See _M_release(),
       // destroy() must observe results of dispose()
__atomic_thread_fence (__ATOMIC_ACQ_REL4);
     }
   _M_destroy();
 }
    }

    long
    _M_get_use_count() const noexcept
    {
      // No memory barrier is used here so there is no synchronization
      // with other threads.
      return __atomic_load_n(&_M_use_count, __ATOMIC_RELAXED0);
    }

  private:
    _Sp_counted_base(_Sp_counted_base const&) = delete;
    _Sp_counted_base& operator=(_Sp_counted_base const&) = delete;

    _Atomic_word  _M_use_count;     // #shared
    _Atomic_word  _M_weak_count;    // #weak + (#shared != 0)
  };

template<>
  inline void
  _Sp_counted_base<_S_single>::
  _M_add_ref_lock()
  {
    if (_M_use_count == 0)
__throw_bad_weak_ptr();
    ++_M_use_count;
  }

template<>
  inline void
  _Sp_counted_base<_S_mutex>::
  _M_add_ref_lock()
  {
    __gnu_cxx::__scoped_lock sentry(*this);
    if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0)
{
 _M_use_count = 0;
 __throw_bad_weak_ptr();
}
  }

template<>
  inline void
  _Sp_counted_base<_S_atomic>::
  _M_add_ref_lock()
  {
    // Perform lock-free add-if-not-zero operation.
    _Atomic_word __count = _M_get_use_count();
    do
{
 if (__count == 0)
   __throw_bad_weak_ptr();
 // Replace the current counter value with the old value + 1, as
 // long as it's not changed meanwhile.
}
    while (!__atomic_compare_exchange_n(&_M_use_count, &__count, __count + 1,
			  true, __ATOMIC_ACQ_REL4,
			  __ATOMIC_RELAXED0));
  }

template<>
  inline bool
  _Sp_counted_base<_S_single>::
  _M_add_ref_lock_nothrow()
  {
    if (_M_use_count == 0)
return false;
    ++_M_use_count;
    return true;
  }

template<>
  inline bool
  _Sp_counted_base<_S_mutex>::
  _M_add_ref_lock_nothrow()
  {
    __gnu_cxx::__scoped_lock sentry(*this);
    if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0)
{
 _M_use_count = 0;
 return false;
}
    return true;
  }

template<>
  inline bool
  _Sp_counted_base<_S_atomic>::
  _M_add_ref_lock_nothrow()
  {
    // Perform lock-free add-if-not-zero operation.
    _Atomic_word __count = _M_get_use_count();
    do
{
 if (__count == 0)
   return false;
 // Replace the current counter value with the old value + 1, as
 // long as it's not changed meanwhile.
}
    while (!__atomic_compare_exchange_n(&_M_use_count, &__count, __count + 1,
			  true, __ATOMIC_ACQ_REL4,
			  __ATOMIC_RELAXED0));
    return true;
  }

template<>
  inline void
  _Sp_counted_base<_S_single>::_M_add_ref_copy()
  { ++_M_use_count; }

template<>
  inline void
  _Sp_counted_base<_S_single>::_M_release() noexcept
  {
    if (--_M_use_count == 0)
      {
        _M_dispose();
        if (--_M_weak_count == 0)
          _M_destroy();
      }
  }

template<>
  inline void
  _Sp_counted_base<_S_single>::_M_weak_add_ref() noexcept
  { ++_M_weak_count; }

template<>
  inline void
  _Sp_counted_base<_S_single>::_M_weak_release() noexcept
  {
    if (--_M_weak_count == 0)
      _M_destroy();
  }

template<>
  inline long
  _Sp_counted_base<_S_single>::_M_get_use_count() const noexcept
  { return _M_use_count; }


// Forward declarations.
template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
  class __shared_ptr;

template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
  class __weak_ptr;

template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
  class __enable_shared_from_this;

template<typename _Tp>
  class shared_ptr;

template<typename _Tp>
  class weak_ptr;

template<typename _Tp>
  struct owner_less;

template<typename _Tp>
  class enable_shared_from_this;

template<_Lock_policy _Lp = __default_lock_policy>
  class __weak_count;

template<_Lock_policy _Lp = __default_lock_policy>
  class __shared_count;


// Counted ptr with no deleter or allocator support
template<typename _Ptr, _Lock_policy _Lp>
  class _Sp_counted_ptr final : public _Sp_counted_base<_Lp>
  {
  public:
    explicit
    _Sp_counted_ptr(_Ptr __p) noexcept
    : _M_ptr(__p) { }

    virtual void
    _M_dispose() noexcept
    { delete _M_ptr; }

    virtual void
    _M_destroy() noexcept
    { delete this; }

    virtual void*
    _M_get_deleter(const std::type_info&) noexcept
    { return nullptr; }

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

  private:
    _Ptr             _M_ptr;
  };

template<>
  inline void
  _Sp_counted_ptr<nullptr_t, _S_single>::_M_dispose() noexcept { }

template<>
  inline void
  _Sp_counted_ptr<nullptr_t, _S_mutex>::_M_dispose() noexcept { }

template<>
  inline void
  _Sp_counted_ptr<nullptr_t, _S_atomic>::_M_dispose() noexcept { }

template<int _Nm, typename _Tp,
  bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)>
  struct _Sp_ebo_helper;

/// Specialization using EBO.
template<int _Nm, typename _Tp>
  struct _Sp_ebo_helper<_Nm, _Tp, true> : private _Tp
  {
    explicit _Sp_ebo_helper(const _Tp& __tp) : _Tp(__tp) { }
    explicit _Sp_ebo_helper(_Tp&& __tp) : _Tp(std::move(__tp)) { }

    static _Tp&
    _S_get(_Sp_ebo_helper& __eboh) { return static_cast<_Tp&>(__eboh); }
  };

/// Specialization not using EBO.
template<int _Nm, typename _Tp>
  struct _Sp_ebo_helper<_Nm, _Tp, false>
  {
    explicit _Sp_ebo_helper(const _Tp& __tp) : _M_tp(__tp) { }
    explicit _Sp_ebo_helper(_Tp&& __tp) : _M_tp(std::move(__tp)) { }

    static _Tp&
    _S_get(_Sp_ebo_helper& __eboh)
    { return __eboh._M_tp; }

  private:
    _Tp _M_tp;
  };

// Support for custom deleter and/or allocator
template<typename _Ptr, typename _Deleter, typename _Alloc, _Lock_policy _Lp>
  class _Sp_counted_deleter final : public _Sp_counted_base<_Lp>
  {
    class _Impl : _Sp_ebo_helper<0, _Deleter>, _Sp_ebo_helper<1, _Alloc>
    {
typedef _Sp_ebo_helper<0, _Deleter>	_Del_base;
typedef _Sp_ebo_helper<1, _Alloc>	_Alloc_base;

    public:
_Impl(_Ptr __p, _Deleter __d, const _Alloc& __a) noexcept
: _M_ptr(__p), _Del_base(std::move(__d)), _Alloc_base(__a)
{ }

_Deleter& _M_del() noexcept { return _Del_base::_S_get(*this); }
_Alloc& _M_alloc() noexcept { return _Alloc_base::_S_get(*this); }

_Ptr _M_ptr;
    };

  public:
    using __allocator_type = __alloc_rebind<_Alloc, _Sp_counted_deleter>;

    // __d(__p) must not throw.
    _Sp_counted_deleter(_Ptr __p, _Deleter __d) noexcept
    : _M_impl(__p, std::move(__d), _Alloc()) { }

    // __d(__p) must not throw.
    _Sp_counted_deleter(_Ptr __p, _Deleter __d, const _Alloc& __a) noexcept
    : _M_impl(__p, std::move(__d), __a) { }

    ~_Sp_counted_deleter() noexcept { }

    virtual void
    _M_dispose() noexcept
    { _M_impl._M_del()(_M_impl._M_ptr); }

    virtual void
    _M_destroy() noexcept
    {
__allocator_type __a(_M_impl._M_alloc());
__allocated_ptr<__allocator_type> __guard_ptr{ __a, this };
this->~_Sp_counted_deleter();
    }

    virtual void*
    _M_get_deleter(const std::type_info& __ti) noexcept
    {
483#if __cpp_rtti199711
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2400. shared_ptr's get_deleter() should use addressof()
      return __ti == typeid(_Deleter)
 ? std::__addressof(_M_impl._M_del())
 : nullptr;
489#else
      return nullptr;
491#endif
    }

  private:
    _Impl _M_impl;
  };

// helpers for make_shared / allocate_shared

struct _Sp_make_shared_tag { };

template<typename _Tp, typename _Alloc, _Lock_policy _Lp>
  class _Sp_counted_ptr_inplace final : public _Sp_counted_base<_Lp>
  {
    class _Impl : _Sp_ebo_helper<0, _Alloc>
    {
typedef _Sp_ebo_helper<0, _Alloc>	_A_base;

    public:
explicit _Impl(_Alloc __a) noexcept : _A_base(__a) { }

_Alloc& _M_alloc() noexcept { return _A_base::_S_get(*this); }

__gnu_cxx::__aligned_buffer<_Tp> _M_storage;
    };

  public:
    using __allocator_type = __alloc_rebind<_Alloc, _Sp_counted_ptr_inplace>;

    template<typename... _Args>
_Sp_counted_ptr_inplace(_Alloc __a, _Args&&... __args)
: _M_impl(__a)
{
 // _GLIBCXX_RESOLVE_LIB_DEFECTS
 // 2070.  allocate_shared should use allocator_traits<A>::construct
 allocator_traits<_Alloc>::construct(__a, _M_ptr(),
     std::forward<_Args>(__args)...); // might throw
}

    ~_Sp_counted_ptr_inplace() noexcept { }

    virtual void
    _M_dispose() noexcept
    {
allocator_traits<_Alloc>::destroy(_M_impl._M_alloc(), _M_ptr());
    }

    // Override because the allocator needs to know the dynamic type
    virtual void
    _M_destroy() noexcept
    {
__allocator_type __a(_M_impl._M_alloc());
__allocated_ptr<__allocator_type> __guard_ptr{ __a, this };
this->~_Sp_counted_ptr_inplace();
    }

    // Sneaky trick so __shared_ptr can get the managed pointer
    virtual void*
    _M_get_deleter(const std::type_info& __ti) noexcept
    {
551#if __cpp_rtti199711
if (__ti == typeid(_Sp_make_shared_tag))
 return const_cast<typename remove_cv<_Tp>::type*>(_M_ptr());
554#endif
return nullptr;
    }

  private:
    _Tp* _M_ptr() noexcept { return _M_impl._M_storage._M_ptr(); }

    _Impl _M_impl;
  };

// The default deleter for shared_ptr<T[]> and shared_ptr<T[N]>.
struct __sp_array_delete
{
  template<typename _Yp>
    void operator()(_Yp* __p) const { delete[] __p; }
};

template<_Lock_policy _Lp>
  class __shared_count
  {
  public:
    constexpr __shared_count() noexcept : _M_pi(0)
    { }

    template<typename _Ptr>
      explicit
__shared_count(_Ptr __p) : _M_pi(0)
{
 __tryif (true)
   {
     _M_pi = new _Sp_counted_ptr<_Ptr, _Lp>(__p);
13
←
Memory is allocated→
   }
 __catch(...)if (false)
   {
     delete __p;
     __throw_exception_again;
   }
}

    template<typename _Ptr>
__shared_count(_Ptr __p, /* is_array = */ false_type)
: __shared_count(__p)
12
←
Calling constructor for '__shared_count'→
14
←
Returning from constructor for '__shared_count'→
{ }

    template<typename _Ptr>
__shared_count(_Ptr __p, /* is_array = */ true_type)
: __shared_count(__p, __sp_array_delete{}, allocator<void>())
{ }

    template<typename _Ptr, typename _Deleter>
__shared_count(_Ptr __p, _Deleter __d)
: __shared_count(__p, std::move(__d), allocator<void>())
{ }

    template<typename _Ptr, typename _Deleter, typename _Alloc>
__shared_count(_Ptr __p, _Deleter __d, _Alloc __a) : _M_pi(0)
{
 typedef _Sp_counted_deleter<_Ptr, _Deleter, _Alloc, _Lp> _Sp_cd_type;
 __tryif (true)
   {
     typename _Sp_cd_type::__allocator_type __a2(__a);
     auto __guard = std::__allocate_guarded(__a2);
     _Sp_cd_type* __mem = __guard.get();
     ::new (__mem) _Sp_cd_type(__p, std::move(__d), std::move(__a));
     _M_pi = __mem;
     __guard = nullptr;
   }
 __catch(...)if (false)
   {
     __d(__p); // Call _Deleter on __p.
     __throw_exception_again;
   }
}

    template<typename _Tp, typename _Alloc, typename... _Args>
__shared_count(_Sp_make_shared_tag, _Tp*, const _Alloc& __a,
       _Args&&... __args)
: _M_pi(0)
{
 typedef _Sp_counted_ptr_inplace<_Tp, _Alloc, _Lp> _Sp_cp_type;
 typename _Sp_cp_type::__allocator_type __a2(__a);
 auto __guard = std::__allocate_guarded(__a2);
 _Sp_cp_type* __mem = __guard.get();
 ::new (__mem) _Sp_cp_type(std::move(__a),
		    std::forward<_Args>(__args)...);
 _M_pi = __mem;
 __guard = nullptr;
}

643#if _GLIBCXX_USE_DEPRECATED1
    // Special case for auto_ptr<_Tp> to provide the strong guarantee.
    template<typename _Tp>
      explicit
__shared_count(std::auto_ptr<_Tp>&& __r);
648#endif

    // Special case for unique_ptr<_Tp,_Del> to provide the strong guarantee.
    template<typename _Tp, typename _Del>
      explicit
__shared_count(std::unique_ptr<_Tp, _Del>&& __r) : _M_pi(0)
{
 // _GLIBCXX_RESOLVE_LIB_DEFECTS
 // 2415. Inconsistency between unique_ptr and shared_ptr
 if (__r.get() == nullptr)
   return;

 using _Ptr = typename unique_ptr<_Tp, _Del>::pointer;
 using _Del2 = typename conditional<is_reference<_Del>::value,
     reference_wrapper<typename remove_reference<_Del>::type>,
     _Del>::type;
 using _Sp_cd_type
   = _Sp_counted_deleter<_Ptr, _Del2, allocator<void>, _Lp>;
 using _Alloc = allocator<_Sp_cd_type>;
 using _Alloc_traits = allocator_traits<_Alloc>;
 _Alloc __a;
 _Sp_cd_type* __mem = _Alloc_traits::allocate(__a, 1);
 _Alloc_traits::construct(__a, __mem, __r.release(),
		   __r.get_deleter());  // non-throwing
 _M_pi = __mem;
}

    // Throw bad_weak_ptr when __r._M_get_use_count() == 0.
    explicit __shared_count(const __weak_count<_Lp>& __r);

    // Does not throw if __r._M_get_use_count() == 0, caller must check.
    explicit __shared_count(const __weak_count<_Lp>& __r, std::nothrow_t);

    ~__shared_count() noexcept
    {
if (_M_pi != nullptr)
 _M_pi->_M_release();
    }

    __shared_count(const __shared_count& __r) noexcept
    : _M_pi(__r._M_pi)
    {
if (_M_pi != 0)
 _M_pi->_M_add_ref_copy();
    }

    __shared_count&
    operator=(const __shared_count& __r) noexcept
    {
_Sp_counted_base<_Lp>* __tmp = __r._M_pi;
if (__tmp != _M_pi)
 {
   if (__tmp != 0)
     __tmp->_M_add_ref_copy();
   if (_M_pi != 0)
     _M_pi->_M_release();
   _M_pi = __tmp;
 }
return *this;
    }

    void
    _M_swap(__shared_count& __r) noexcept
    {
_Sp_counted_base<_Lp>* __tmp = __r._M_pi;
__r._M_pi = _M_pi;
_M_pi = __tmp;
    }

    long
    _M_get_use_count() const noexcept
    { return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; }

    bool
    _M_unique() const noexcept
    { return this->_M_get_use_count() == 1; }

    void*
    _M_get_deleter(const std::type_info& __ti) const noexcept
    { return _M_pi ? _M_pi->_M_get_deleter(__ti) : nullptr; }

    bool
    _M_less(const __shared_count& __rhs) const noexcept
    { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); }

    bool
    _M_less(const __weak_count<_Lp>& __rhs) const noexcept
    { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); }

    // Friend function injected into enclosing namespace and found by ADL
    friend inline bool
    operator==(const __shared_count& __a, const __shared_count& __b) noexcept
    { return __a._M_pi == __b._M_pi; }

  private:
    friend class __weak_count<_Lp>;

    _Sp_counted_base<_Lp>*  _M_pi;
  };


template<_Lock_policy _Lp>
  class __weak_count
  {
  public:
    constexpr __weak_count() noexcept : _M_pi(nullptr)
    { }

    __weak_count(const __shared_count<_Lp>& __r) noexcept
    : _M_pi(__r._M_pi)
    {
if (_M_pi != nullptr)
 _M_pi->_M_weak_add_ref();
    }

    __weak_count(const __weak_count& __r) noexcept
    : _M_pi(__r._M_pi)
    {
if (_M_pi != nullptr)
 _M_pi->_M_weak_add_ref();
    }

    __weak_count(__weak_count&& __r) noexcept
    : _M_pi(__r._M_pi)
    { __r._M_pi = nullptr; }

    ~__weak_count() noexcept
    {
if (_M_pi != nullptr)
 _M_pi->_M_weak_release();
    }

    __weak_count&
    operator=(const __shared_count<_Lp>& __r) noexcept
    {
_Sp_counted_base<_Lp>* __tmp = __r._M_pi;
if (__tmp != nullptr)
 __tmp->_M_weak_add_ref();
if (_M_pi != nullptr)
 _M_pi->_M_weak_release();
_M_pi = __tmp;
return *this;
    }

    __weak_count&
    operator=(const __weak_count& __r) noexcept
    {
_Sp_counted_base<_Lp>* __tmp = __r._M_pi;
if (__tmp != nullptr)
 __tmp->_M_weak_add_ref();
if (_M_pi != nullptr)
 _M_pi->_M_weak_release();
_M_pi = __tmp;
return *this;
    }

    __weak_count&
    operator=(__weak_count&& __r) noexcept
    {
if (_M_pi != nullptr)
 _M_pi->_M_weak_release();
_M_pi = __r._M_pi;
      __r._M_pi = nullptr;
return *this;
    }

    void
    _M_swap(__weak_count& __r) noexcept
    {
_Sp_counted_base<_Lp>* __tmp = __r._M_pi;
__r._M_pi = _M_pi;
_M_pi = __tmp;
    }

    long
    _M_get_use_count() const noexcept
    { return _M_pi != nullptr ? _M_pi->_M_get_use_count() : 0; }

    bool
    _M_less(const __weak_count& __rhs) const noexcept
    { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); }

    bool
    _M_less(const __shared_count<_Lp>& __rhs) const noexcept
    { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); }

    // Friend function injected into enclosing namespace and found by ADL
    friend inline bool
    operator==(const __weak_count& __a, const __weak_count& __b) noexcept
    { return __a._M_pi == __b._M_pi; }

  private:
    friend class __shared_count<_Lp>;

    _Sp_counted_base<_Lp>*  _M_pi;
  };

// Now that __weak_count is defined we can define this constructor:
template<_Lock_policy _Lp>
  inline
  __shared_count<_Lp>::__shared_count(const __weak_count<_Lp>& __r)
  : _M_pi(__r._M_pi)
  {
    if (_M_pi != nullptr)
_M_pi->_M_add_ref_lock();
    else
__throw_bad_weak_ptr();
  }

// Now that __weak_count is defined we can define this constructor:
template<_Lock_policy _Lp>
  inline
  __shared_count<_Lp>::
  __shared_count(const __weak_count<_Lp>& __r, std::nothrow_t)
  : _M_pi(__r._M_pi)
  {
    if (_M_pi != nullptr)
if (!_M_pi->_M_add_ref_lock_nothrow())
 _M_pi = nullptr;
  }

869#define __cpp_lib_shared_ptr_arrays201603 201603

// Helper traits for shared_ptr of array:

// A pointer type Y* is said to be compatible with a pointer type T* when
// either Y* is convertible to T* or Y is U[N] and T is U cv [].
template<typename _Yp_ptr, typename _Tp_ptr>
  struct __sp_compatible_with
  : false_type
  { };

template<typename _Yp, typename _Tp>
  struct __sp_compatible_with<_Yp*, _Tp*>
  : is_convertible<_Yp*, _Tp*>::type
  { };

template<typename _Up, size_t _Nm>
  struct __sp_compatible_with<_Up(*)[_Nm], _Up(*)[]>
  : true_type
  { };

template<typename _Up, size_t _Nm>
  struct __sp_compatible_with<_Up(*)[_Nm], const _Up(*)[]>
  : true_type
  { };

template<typename _Up, size_t _Nm>
  struct __sp_compatible_with<_Up(*)[_Nm], volatile _Up(*)[]>
  : true_type
  { };

template<typename _Up, size_t _Nm>
  struct __sp_compatible_with<_Up(*)[_Nm], const volatile _Up(*)[]>
  : true_type
  { };

// Test conversion from Y(*)[N] to U(*)[N] without forming invalid type Y[N].
template<typename _Up, size_t _Nm, typename _Yp, typename = void>
  struct __sp_is_constructible_arrN
  : false_type
  { };

template<typename _Up, size_t _Nm, typename _Yp>
  struct __sp_is_constructible_arrN<_Up, _Nm, _Yp, __void_t<_Yp[_Nm]>>
  : is_convertible<_Yp(*)[_Nm], _Up(*)[_Nm]>::type
  { };

// Test conversion from Y(*)[] to U(*)[] without forming invalid type Y[].
template<typename _Up, typename _Yp, typename = void>
  struct __sp_is_constructible_arr
  : false_type
  { };

template<typename _Up, typename _Yp>
  struct __sp_is_constructible_arr<_Up, _Yp, __void_t<_Yp[]>>
  : is_convertible<_Yp(*)[], _Up(*)[]>::type
  { };

// Trait to check if shared_ptr<T> can be constructed from Y*.
template<typename _Tp, typename _Yp>
  struct __sp_is_constructible;

// When T is U[N], Y(*)[N] shall be convertible to T*;
template<typename _Up, size_t _Nm, typename _Yp>
  struct __sp_is_constructible<_Up[_Nm], _Yp>
  : __sp_is_constructible_arrN<_Up, _Nm, _Yp>::type
  { };

// when T is U[], Y(*)[] shall be convertible to T*;
template<typename _Up, typename _Yp>
  struct __sp_is_constructible<_Up[], _Yp>
  : __sp_is_constructible_arr<_Up, _Yp>::type
  { };

// otherwise, Y* shall be convertible to T*.
template<typename _Tp, typename _Yp>
  struct __sp_is_constructible
  : is_convertible<_Yp*, _Tp*>::type
  { };


// Define operator* and operator-> for shared_ptr<T>.
template<typename _Tp, _Lock_policy _Lp,
  bool = is_array<_Tp>::value, bool = is_void<_Tp>::value>
  class __shared_ptr_access
  {
  public:
    using element_type = _Tp;

    element_type&
    operator*() const noexcept
    {
__glibcxx_assert(_M_get() != nullptr);
return *_M_get();
    }

    element_type*
    operator->() const noexcept
    {
_GLIBCXX_DEBUG_PEDASSERT(_M_get() != nullptr);
return _M_get();
    }

  private:
    element_type*
    _M_get() const noexcept
    { return static_cast<const __shared_ptr<_Tp, _Lp>*>(this)->get(); }
  };

// Define operator-> for shared_ptr<cv void>.
template<typename _Tp, _Lock_policy _Lp>
  class __shared_ptr_access<_Tp, _Lp, false, true>
  {
  public:
    using element_type = _Tp;

    element_type*
    operator->() const noexcept
    {
auto __ptr = static_cast<const __shared_ptr<_Tp, _Lp>*>(this)->get();
_GLIBCXX_DEBUG_PEDASSERT(__ptr != nullptr);
return __ptr;
    }
  };

// Define operator[] for shared_ptr<T[]> and shared_ptr<T[N]>.
template<typename _Tp, _Lock_policy _Lp>
  class __shared_ptr_access<_Tp, _Lp, true, false>
  {
  public:
    using element_type = typename remove_extent<_Tp>::type;

1001#if __cplusplus201103L <= 201402L
    [[__deprecated__("shared_ptr<T[]>::operator* is absent from C++17")]]
    element_type&
    operator*() const noexcept
    {
__glibcxx_assert(_M_get() != nullptr);
return *_M_get();
    }

    [[__deprecated__("shared_ptr<T[]>::operator-> is absent from C++17")]]
    element_type*
    operator->() const noexcept
    {
_GLIBCXX_DEBUG_PEDASSERT(_M_get() != nullptr);
return _M_get();
    }
1017#endif

    element_type&
    operator[](ptrdiff_t __i) const
    {
__glibcxx_assert(_M_get() != nullptr);
__glibcxx_assert(!extent<_Tp>::value || __i < extent<_Tp>::value);
return _M_get()[__i];
    }

  private:
    element_type*
    _M_get() const noexcept
    { return static_cast<const __shared_ptr<_Tp, _Lp>*>(this)->get(); }
  };

template<typename _Tp, _Lock_policy _Lp>
  class __shared_ptr
  : public __shared_ptr_access<_Tp, _Lp>
  {
  public:
    using element_type = typename remove_extent<_Tp>::type;

  private:
    // Constraint for taking ownership of a pointer of type _Yp*:
    template<typename _Yp>
using _SafeConv
 = typename enable_if<__sp_is_constructible<_Tp, _Yp>::value>::type;

    // Constraint for construction from shared_ptr and weak_ptr:
    template<typename _Yp, typename _Res = void>
using _Compatible = typename
 enable_if<__sp_compatible_with<_Yp*, _Tp*>::value, _Res>::type;

    // Constraint for assignment from shared_ptr and weak_ptr:
    template<typename _Yp>
using _Assignable = _Compatible<_Yp, __shared_ptr&>;

    // Constraint for construction from unique_ptr:
    template<typename _Yp, typename _Del, typename _Res = void,
      typename _Ptr = typename unique_ptr<_Yp, _Del>::pointer>
using _UniqCompatible = typename enable_if<__and_<
 __sp_compatible_with<_Yp*, _Tp*>, is_convertible<_Ptr, element_type*>
 >::value, _Res>::type;

    // Constraint for assignment from unique_ptr:
    template<typename _Yp, typename _Del>
using _UniqAssignable = _UniqCompatible<_Yp, _Del, __shared_ptr&>;

  public:

1068#if __cplusplus201103L > 201402L
    using weak_type = __weak_ptr<_Tp, _Lp>;
1070#endif

    constexpr __shared_ptr() noexcept
    : _M_ptr(0), _M_refcount()
    { }

    template<typename _Yp, typename = _SafeConv<_Yp>>
explicit
__shared_ptr(_Yp* __p)
: _M_ptr(__p), _M_refcount(__p, typename is_array<_Tp>::type())
11
←
Calling constructor for '__shared_count'→
15
←
Returning from constructor for '__shared_count'→
{
 static_assert( !is_void<_Yp>::value, "incomplete type" );
 static_assert( sizeof(_Yp) > 0, "incomplete type" );
 _M_enable_shared_from_this_with(__p);
}

    template<typename _Yp, typename _Deleter, typename = _SafeConv<_Yp>>
__shared_ptr(_Yp* __p, _Deleter __d)
: _M_ptr(__p), _M_refcount(__p, std::move(__d))
{
 static_assert(__is_invocable<_Deleter&, _Yp*&>::value,
     "deleter expression d(p) is well-formed");
 _M_enable_shared_from_this_with(__p);
}

    template<typename _Yp, typename _Deleter, typename _Alloc,
      typename = _SafeConv<_Yp>>
__shared_ptr(_Yp* __p, _Deleter __d, _Alloc __a)
: _M_ptr(__p), _M_refcount(__p, std::move(__d), std::move(__a))
{
 static_assert(__is_invocable<_Deleter&, _Yp*&>::value,
     "deleter expression d(p) is well-formed");
 _M_enable_shared_from_this_with(__p);
}

    template<typename _Deleter>
__shared_ptr(nullptr_t __p, _Deleter __d)
: _M_ptr(0), _M_refcount(__p, std::move(__d))
{ }

    template<typename _Deleter, typename _Alloc>
      __shared_ptr(nullptr_t __p, _Deleter __d, _Alloc __a)
: _M_ptr(0), _M_refcount(__p, std::move(__d), std::move(__a))
{ }

    template<typename _Yp>
__shared_ptr(const __shared_ptr<_Yp, _Lp>& __r,
     element_type* __p) noexcept
: _M_ptr(__p), _M_refcount(__r._M_refcount) // never throws
{ }

    __shared_ptr(const __shared_ptr&) noexcept = default;
    __shared_ptr& operator=(const __shared_ptr&) noexcept = default;
    ~__shared_ptr() = default;

    template<typename _Yp, typename = _Compatible<_Yp>>
__shared_ptr(const __shared_ptr<_Yp, _Lp>& __r) noexcept
: _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount)
{ }

    __shared_ptr(__shared_ptr&& __r) noexcept
    : _M_ptr(__r._M_ptr), _M_refcount()
    {
_M_refcount._M_swap(__r._M_refcount);
__r._M_ptr = 0;
    }

    template<typename _Yp, typename = _Compatible<_Yp>>
__shared_ptr(__shared_ptr<_Yp, _Lp>&& __r) noexcept
: _M_ptr(__r._M_ptr), _M_refcount()
{
 _M_refcount._M_swap(__r._M_refcount);
 __r._M_ptr = 0;
}

    template<typename _Yp, typename = _Compatible<_Yp>>
explicit __shared_ptr(const __weak_ptr<_Yp, _Lp>& __r)
: _M_refcount(__r._M_refcount) // may throw
{
 // It is now safe to copy __r._M_ptr, as
 // _M_refcount(__r._M_refcount) did not throw.
 _M_ptr = __r._M_ptr;
}

    // If an exception is thrown this constructor has no effect.
    template<typename _Yp, typename _Del,
      typename = _UniqCompatible<_Yp, _Del>>
__shared_ptr(unique_ptr<_Yp, _Del>&& __r)
: _M_ptr(__r.get()), _M_refcount()
{
 auto __raw = _S_raw_ptr(__r.get());
 _M_refcount = __shared_count<_Lp>(std::move(__r));
 _M_enable_shared_from_this_with(__raw);
}

1165#if __cplusplus201103L <= 201402L && _GLIBCXX_USE_DEPRECATED1
  protected:
    // If an exception is thrown this constructor has no effect.
    template<typename _Tp1, typename _Del,
      typename enable_if<__and_<
 __not_<is_array<_Tp>>, is_array<_Tp1>,
        is_convertible<typename unique_ptr<_Tp1, _Del>::pointer, _Tp*>
      >::value, bool>::type = true>
__shared_ptr(unique_ptr<_Tp1, _Del>&& __r, __sp_array_delete)
: _M_ptr(__r.get()), _M_refcount()
{
 auto __raw = _S_raw_ptr(__r.get());
 _M_refcount = __shared_count<_Lp>(std::move(__r));
 _M_enable_shared_from_this_with(__raw);
}
  public:
1181#endif

1183#if _GLIBCXX_USE_DEPRECATED1
    // Postcondition: use_count() == 1 and __r.get() == 0
    template<typename _Yp, typename = _Compatible<_Yp>>
__shared_ptr(auto_ptr<_Yp>&& __r);
1187#endif

    constexpr __shared_ptr(nullptr_t) noexcept : __shared_ptr() { }

    template<typename _Yp>
_Assignable<_Yp>
operator=(const __shared_ptr<_Yp, _Lp>& __r) noexcept
{
 _M_ptr = __r._M_ptr;
 _M_refcount = __r._M_refcount; // __shared_count::op= doesn't throw
 return *this;
}

1200#if _GLIBCXX_USE_DEPRECATED1
    template<typename _Yp>
_Assignable<_Yp>
operator=(auto_ptr<_Yp>&& __r)
{
 __shared_ptr(std::move(__r)).swap(*this);
 return *this;
}
1208#endif

    __shared_ptr&
    operator=(__shared_ptr&& __r) noexcept
    {
__shared_ptr(std::move(__r)).swap(*this);
return *this;
    }

    template<class _Yp>
_Assignable<_Yp>
operator=(__shared_ptr<_Yp, _Lp>&& __r) noexcept
{
 __shared_ptr(std::move(__r)).swap(*this);
 return *this;
}

    template<typename _Yp, typename _Del>
_UniqAssignable<_Yp, _Del>
operator=(unique_ptr<_Yp, _Del>&& __r)
{
 __shared_ptr(std::move(__r)).swap(*this);
 return *this;
}

    void
    reset() noexcept
    { __shared_ptr().swap(*this); }

    template<typename _Yp>
_SafeConv<_Yp>
reset(_Yp* __p) // _Yp must be complete.
{
 // Catch self-reset errors.
 __glibcxx_assert(__p == 0 || __p != _M_ptr);
 __shared_ptr(__p).swap(*this);
10
←
Calling constructor for '__shared_ptr'→
16
←
Returning from constructor for '__shared_ptr'→
}

    template<typename _Yp, typename _Deleter>
_SafeConv<_Yp>
reset(_Yp* __p, _Deleter __d)
{ __shared_ptr(__p, std::move(__d)).swap(*this); }

    template<typename _Yp, typename _Deleter, typename _Alloc>
_SafeConv<_Yp>
reset(_Yp* __p, _Deleter __d, _Alloc __a)
      { __shared_ptr(__p, std::move(__d), std::move(__a)).swap(*this); }

    element_type*
    get() const noexcept
    { return _M_ptr; }

    explicit operator bool() const // never throws
    { return _M_ptr == 0 ? false : true; }

    bool
    unique() const noexcept
    { return _M_refcount._M_unique(); }

    long
    use_count() const noexcept
    { return _M_refcount._M_get_use_count(); }

    void
    swap(__shared_ptr<_Tp, _Lp>& __other) noexcept
    {
std::swap(_M_ptr, __other._M_ptr);
_M_refcount._M_swap(__other._M_refcount);
    }

    template<typename _Tp1>
bool
owner_before(__shared_ptr<_Tp1, _Lp> const& __rhs) const noexcept
{ return _M_refcount._M_less(__rhs._M_refcount); }

    template<typename _Tp1>
bool
owner_before(__weak_ptr<_Tp1, _Lp> const& __rhs) const noexcept
{ return _M_refcount._M_less(__rhs._M_refcount); }

1288#if __cpp_rtti199711
  protected:
    // This constructor is non-standard, it is used by allocate_shared.
    template<typename _Alloc, typename... _Args>
__shared_ptr(_Sp_make_shared_tag __tag, const _Alloc& __a,
     _Args&&... __args)
: _M_ptr(), _M_refcount(__tag, (_Tp*)0, __a,
		std::forward<_Args>(__args)...)
{
 // _M_ptr needs to point to the newly constructed object.
 // This relies on _Sp_counted_ptr_inplace::_M_get_deleter.
 void* __p = _M_refcount._M_get_deleter(typeid(__tag));
 _M_ptr = static_cast<_Tp*>(__p);
 _M_enable_shared_from_this_with(_M_ptr);
}
1303#else
    template<typename _Alloc>
      struct _Deleter
      {
        void operator()(typename _Alloc::value_type* __ptr)
        {
   __allocated_ptr<_Alloc> __guard{ _M_alloc, __ptr };
   allocator_traits<_Alloc>::destroy(_M_alloc, __guard.get());
        }
        _Alloc _M_alloc;
      };

    template<typename _Alloc, typename... _Args>
__shared_ptr(_Sp_make_shared_tag __tag, const _Alloc& __a,
     _Args&&... __args)
: _M_ptr(), _M_refcount()
{
 typedef typename allocator_traits<_Alloc>::template
   rebind_traits<typename std::remove_cv<_Tp>::type> __traits;
 _Deleter<typename __traits::allocator_type> __del = { __a };
 auto __guard = std::__allocate_guarded(__del._M_alloc);
 auto __ptr = __guard.get();
 // _GLIBCXX_RESOLVE_LIB_DEFECTS
 // 2070. allocate_shared should use allocator_traits<A>::construct
 __traits::construct(__del._M_alloc, __ptr,
	      std::forward<_Args>(__args)...);
 __guard = nullptr;
 __shared_count<_Lp> __count(__ptr, __del, __del._M_alloc);
 _M_refcount._M_swap(__count);
 _M_ptr = __ptr;
 _M_enable_shared_from_this_with(_M_ptr);
}
1335#endif

    template<typename _Tp1, _Lock_policy _Lp1, typename _Alloc,
      typename... _Args>
friend __shared_ptr<_Tp1, _Lp1>
__allocate_shared(const _Alloc& __a, _Args&&... __args);

    // This constructor is used by __weak_ptr::lock() and
    // shared_ptr::shared_ptr(const weak_ptr&, std::nothrow_t).
    __shared_ptr(const __weak_ptr<_Tp, _Lp>& __r, std::nothrow_t)
    : _M_refcount(__r._M_refcount, std::nothrow)
    {
_M_ptr = _M_refcount._M_get_use_count() ? __r._M_ptr : nullptr;
    }

    friend class __weak_ptr<_Tp, _Lp>;

  private:

    template<typename _Yp>
using __esft_base_t = decltype(__enable_shared_from_this_base(
     std::declval<const __shared_count<_Lp>&>(),
     std::declval<_Yp*>()));

    // Detect an accessible and unambiguous enable_shared_from_this base.
    template<typename _Yp, typename = void>
struct __has_esft_base
: false_type { };

    template<typename _Yp>
struct __has_esft_base<_Yp, __void_t<__esft_base_t<_Yp>>>
: __not_<is_array<_Tp>> { }; // No enable shared_from_this for arrays

    template<typename _Yp, typename _Yp2 = typename remove_cv<_Yp>::type>
typename enable_if<__has_esft_base<_Yp2>::value>::type
_M_enable_shared_from_this_with(_Yp* __p) noexcept
{
 if (auto __base = __enable_shared_from_this_base(_M_refcount, __p))
   __base->_M_weak_assign(const_cast<_Yp2*>(__p), _M_refcount);
}

    template<typename _Yp, typename _Yp2 = typename remove_cv<_Yp>::type>
typename enable_if<!__has_esft_base<_Yp2>::value>::type
_M_enable_shared_from_this_with(_Yp*) noexcept
{ }

    void*
    _M_get_deleter(const std::type_info& __ti) const noexcept
    { return _M_refcount._M_get_deleter(__ti); }

    template<typename _Tp1>
static _Tp1*
_S_raw_ptr(_Tp1* __ptr)
{ return __ptr; }

    template<typename _Tp1>
static auto
_S_raw_ptr(_Tp1 __ptr) -> decltype(std::__addressof(*__ptr))
{ return std::__addressof(*__ptr); }

    template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr;
    template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr;

    template<typename _Del, typename _Tp1, _Lock_policy _Lp1>
friend _Del* get_deleter(const __shared_ptr<_Tp1, _Lp1>&) noexcept;

    element_type*	   _M_ptr;         // Contained pointer.
    __shared_count<_Lp>  _M_refcount;    // Reference counter.
  };


// 20.7.2.2.7 shared_ptr comparisons
template<typename _Tp1, typename _Tp2, _Lock_policy _Lp>
  inline bool
  operator==(const __shared_ptr<_Tp1, _Lp>& __a,
      const __shared_ptr<_Tp2, _Lp>& __b) noexcept
  { return __a.get() == __b.get(); }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator==(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
  { return !__a; }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator==(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
  { return !__a; }

template<typename _Tp1, typename _Tp2, _Lock_policy _Lp>
  inline bool
  operator!=(const __shared_ptr<_Tp1, _Lp>& __a,
      const __shared_ptr<_Tp2, _Lp>& __b) noexcept
  { return __a.get() != __b.get(); }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator!=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
  { return (bool)__a; }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator!=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
  { return (bool)__a; }

template<typename _Tp, typename _Up, _Lock_policy _Lp>
  inline bool
  operator<(const __shared_ptr<_Tp, _Lp>& __a,
     const __shared_ptr<_Up, _Lp>& __b) noexcept
  {
    using _Tp_elt = typename __shared_ptr<_Tp, _Lp>::element_type;
    using _Up_elt = typename __shared_ptr<_Up, _Lp>::element_type;
    using _Vp = typename common_type<_Tp_elt*, _Up_elt*>::type;
    return less<_Vp>()(__a.get(), __b.get());
  }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator<(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
  {
    using _Tp_elt = typename __shared_ptr<_Tp, _Lp>::element_type;
    return less<_Tp_elt*>()(__a.get(), nullptr);
  }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator<(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
  {
    using _Tp_elt = typename __shared_ptr<_Tp, _Lp>::element_type;
    return less<_Tp_elt*>()(nullptr, __a.get());
  }

template<typename _Tp1, typename _Tp2, _Lock_policy _Lp>
  inline bool
  operator<=(const __shared_ptr<_Tp1, _Lp>& __a,
      const __shared_ptr<_Tp2, _Lp>& __b) noexcept
  { return !(__b < __a); }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator<=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
  { return !(nullptr < __a); }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator<=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
  { return !(__a < nullptr); }

template<typename _Tp1, typename _Tp2, _Lock_policy _Lp>
  inline bool
  operator>(const __shared_ptr<_Tp1, _Lp>& __a,
     const __shared_ptr<_Tp2, _Lp>& __b) noexcept
  { return (__b < __a); }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator>(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
  { return nullptr < __a; }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator>(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
  { return __a < nullptr; }

template<typename _Tp1, typename _Tp2, _Lock_policy _Lp>
  inline bool
  operator>=(const __shared_ptr<_Tp1, _Lp>& __a,
      const __shared_ptr<_Tp2, _Lp>& __b) noexcept
  { return !(__a < __b); }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator>=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
  { return !(__a < nullptr); }

template<typename _Tp, _Lock_policy _Lp>
  inline bool
  operator>=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
  { return !(nullptr < __a); }

template<typename _Sp>
  struct _Sp_less : public binary_function<_Sp, _Sp, bool>
  {
    bool
    operator()(const _Sp& __lhs, const _Sp& __rhs) const noexcept
    {
typedef typename _Sp::element_type element_type;
return std::less<element_type*>()(__lhs.get(), __rhs.get());
    }
  };

template<typename _Tp, _Lock_policy _Lp>
  struct less<__shared_ptr<_Tp, _Lp>>
  : public _Sp_less<__shared_ptr<_Tp, _Lp>>
  { };

// 20.7.2.2.8 shared_ptr specialized algorithms.
template<typename _Tp, _Lock_policy _Lp>
  inline void
  swap(__shared_ptr<_Tp, _Lp>& __a, __shared_ptr<_Tp, _Lp>& __b) noexcept
  { __a.swap(__b); }

// 20.7.2.2.9 shared_ptr casts

// The seemingly equivalent code:
// shared_ptr<_Tp, _Lp>(static_cast<_Tp*>(__r.get()))
// will eventually result in undefined behaviour, attempting to
// delete the same object twice.
/// static_pointer_cast
template<typename _Tp, typename _Tp1, _Lock_policy _Lp>
  inline __shared_ptr<_Tp, _Lp>
  static_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
  {
    using _Sp = __shared_ptr<_Tp, _Lp>;
    return _Sp(__r, static_cast<typename _Sp::element_type*>(__r.get()));
  }

// The seemingly equivalent code:
// shared_ptr<_Tp, _Lp>(const_cast<_Tp*>(__r.get()))
// will eventually result in undefined behaviour, attempting to
// delete the same object twice.
/// const_pointer_cast
template<typename _Tp, typename _Tp1, _Lock_policy _Lp>
  inline __shared_ptr<_Tp, _Lp>
  const_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
  {
    using _Sp = __shared_ptr<_Tp, _Lp>;
    return _Sp(__r, const_cast<typename _Sp::element_type*>(__r.get()));
  }

// The seemingly equivalent code:
// shared_ptr<_Tp, _Lp>(dynamic_cast<_Tp*>(__r.get()))
// will eventually result in undefined behaviour, attempting to
// delete the same object twice.
/// dynamic_pointer_cast
template<typename _Tp, typename _Tp1, _Lock_policy _Lp>
  inline __shared_ptr<_Tp, _Lp>
  dynamic_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
  {
    using _Sp = __shared_ptr<_Tp, _Lp>;
    if (auto* __p = dynamic_cast<typename _Sp::element_type*>(__r.get()))
return _Sp(__r, __p);
    return _Sp();
  }

1579#if __cplusplus201103L > 201402L
template<typename _Tp, typename _Tp1, _Lock_policy _Lp>
  inline __shared_ptr<_Tp, _Lp>
  reinterpret_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
  {
    using _Sp = __shared_ptr<_Tp, _Lp>;
    return _Sp(__r, reinterpret_cast<typename _Sp::element_type*>(__r.get()));
  }
1587#endif

template<typename _Tp, _Lock_policy _Lp>
  class __weak_ptr
  {
    template<typename _Yp, typename _Res = void>
using _Compatible = typename
 enable_if<__sp_compatible_with<_Yp*, _Tp*>::value, _Res>::type;

    // Constraint for assignment from shared_ptr and weak_ptr:
    template<typename _Yp>
using _Assignable = _Compatible<_Yp, __weak_ptr&>;

  public:
    using element_type = typename remove_extent<_Tp>::type;

    constexpr __weak_ptr() noexcept
    : _M_ptr(nullptr), _M_refcount()
    { }

    __weak_ptr(const __weak_ptr&) noexcept = default;

    ~__weak_ptr() = default;

    // The "obvious" converting constructor implementation:
    //
    //  template<typename _Tp1>
    //    __weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r)
    //    : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) // never throws
    //    { }
    //
    // has a serious problem.
    //
    //  __r._M_ptr may already have been invalidated. The _M_ptr(__r._M_ptr)
    //  conversion may require access to *__r._M_ptr (virtual inheritance).
    //
    // It is not possible to avoid spurious access violations since
    // in multithreaded programs __r._M_ptr may be invalidated at any point.
    template<typename _Yp, typename = _Compatible<_Yp>>
__weak_ptr(const __weak_ptr<_Yp, _Lp>& __r) noexcept
: _M_refcount(__r._M_refcount)
      { _M_ptr = __r.lock().get(); }

    template<typename _Yp, typename = _Compatible<_Yp>>
__weak_ptr(const __shared_ptr<_Yp, _Lp>& __r) noexcept
: _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount)
{ }

    __weak_ptr(__weak_ptr&& __r) noexcept
    : _M_ptr(__r._M_ptr), _M_refcount(std::move(__r._M_refcount))
    { __r._M_ptr = nullptr; }

    template<typename _Yp, typename = _Compatible<_Yp>>
__weak_ptr(__weak_ptr<_Yp, _Lp>&& __r) noexcept
: _M_ptr(__r.lock().get()), _M_refcount(std::move(__r._M_refcount))
      { __r._M_ptr = nullptr; }

    __weak_ptr&
    operator=(const __weak_ptr& __r) noexcept = default;

    template<typename _Yp>
_Assignable<_Yp>
operator=(const __weak_ptr<_Yp, _Lp>& __r) noexcept
{
 _M_ptr = __r.lock().get();
 _M_refcount = __r._M_refcount;
 return *this;
}

    template<typename _Yp>
_Assignable<_Yp>
operator=(const __shared_ptr<_Yp, _Lp>& __r) noexcept
{
 _M_ptr = __r._M_ptr;
 _M_refcount = __r._M_refcount;
 return *this;
}

    __weak_ptr&
    operator=(__weak_ptr&& __r) noexcept
    {
_M_ptr = __r._M_ptr;
_M_refcount = std::move(__r._M_refcount);
__r._M_ptr = nullptr;
return *this;
    }

    template<typename _Yp>
_Assignable<_Yp>
operator=(__weak_ptr<_Yp, _Lp>&& __r) noexcept
{
 _M_ptr = __r.lock().get();
 _M_refcount = std::move(__r._M_refcount);
 __r._M_ptr = nullptr;
 return *this;
}

    __shared_ptr<_Tp, _Lp>
    lock() const noexcept
    { return __shared_ptr<element_type, _Lp>(*this, std::nothrow); }

    long
    use_count() const noexcept
    { return _M_refcount._M_get_use_count(); }

    bool
    expired() const noexcept
    { return _M_refcount._M_get_use_count() == 0; }

    template<typename _Tp1>
bool
owner_before(const __shared_ptr<_Tp1, _Lp>& __rhs) const noexcept
{ return _M_refcount._M_less(__rhs._M_refcount); }

    template<typename _Tp1>
bool
owner_before(const __weak_ptr<_Tp1, _Lp>& __rhs) const noexcept
{ return _M_refcount._M_less(__rhs._M_refcount); }

    void
    reset() noexcept
    { __weak_ptr().swap(*this); }

    void
    swap(__weak_ptr& __s) noexcept
    {
std::swap(_M_ptr, __s._M_ptr);
_M_refcount._M_swap(__s._M_refcount);
    }

  private:
    // Used by __enable_shared_from_this.
    void
    _M_assign(_Tp* __ptr, const __shared_count<_Lp>& __refcount) noexcept
    {
if (use_count() == 0)
 {
   _M_ptr = __ptr;
   _M_refcount = __refcount;
 }
    }

    template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr;
    template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr;
    friend class __enable_shared_from_this<_Tp, _Lp>;
    friend class enable_shared_from_this<_Tp>;

    element_type*	 _M_ptr;         // Contained pointer.
    __weak_count<_Lp>  _M_refcount;    // Reference counter.
  };

// 20.7.2.3.6 weak_ptr specialized algorithms.
template<typename _Tp, _Lock_policy _Lp>
  inline void
  swap(__weak_ptr<_Tp, _Lp>& __a, __weak_ptr<_Tp, _Lp>& __b) noexcept
  { __a.swap(__b); }

template<typename _Tp, typename _Tp1>
  struct _Sp_owner_less : public binary_function<_Tp, _Tp, bool>
  {
    bool
    operator()(const _Tp& __lhs, const _Tp& __rhs) const noexcept
    { return __lhs.owner_before(__rhs); }

    bool
    operator()(const _Tp& __lhs, const _Tp1& __rhs) const noexcept
    { return __lhs.owner_before(__rhs); }

    bool
    operator()(const _Tp1& __lhs, const _Tp& __rhs) const noexcept
    { return __lhs.owner_before(__rhs); }
  };

template<>
  struct _Sp_owner_less<void, void>
  {
    template<typename _Tp, typename _Up>
auto
operator()(const _Tp& __lhs, const _Up& __rhs) const noexcept
-> decltype(__lhs.owner_before(__rhs))
{ return __lhs.owner_before(__rhs); }

    using is_transparent = void;
  };

template<typename _Tp, _Lock_policy _Lp>
  struct owner_less<__shared_ptr<_Tp, _Lp>>
  : public _Sp_owner_less<__shared_ptr<_Tp, _Lp>, __weak_ptr<_Tp, _Lp>>
  { };

template<typename _Tp, _Lock_policy _Lp>
  struct owner_less<__weak_ptr<_Tp, _Lp>>
  : public _Sp_owner_less<__weak_ptr<_Tp, _Lp>, __shared_ptr<_Tp, _Lp>>
  { };


template<typename _Tp, _Lock_policy _Lp>
  class __enable_shared_from_this
  {
  protected:
    constexpr __enable_shared_from_this() noexcept { }

    __enable_shared_from_this(const __enable_shared_from_this&) noexcept { }

    __enable_shared_from_this&
    operator=(const __enable_shared_from_this&) noexcept
    { return *this; }

    ~__enable_shared_from_this() { }

  public:
    __shared_ptr<_Tp, _Lp>
    shared_from_this()
    { return __shared_ptr<_Tp, _Lp>(this->_M_weak_this); }

    __shared_ptr<const _Tp, _Lp>
    shared_from_this() const
    { return __shared_ptr<const _Tp, _Lp>(this->_M_weak_this); }

1806#if __cplusplus201103L > 201402L || !defined(__STRICT_ANSI__1) // c++1z or gnu++11
    __weak_ptr<_Tp, _Lp>
    weak_from_this() noexcept
    { return this->_M_weak_this; }

    __weak_ptr<const _Tp, _Lp>
    weak_from_this() const noexcept
    { return this->_M_weak_this; }
1814#endif

  private:
    template<typename _Tp1>
void
_M_weak_assign(_Tp1* __p, const __shared_count<_Lp>& __n) const noexcept
{ _M_weak_this._M_assign(__p, __n); }

    friend const __enable_shared_from_this*
    __enable_shared_from_this_base(const __shared_count<_Lp>&,
		     const __enable_shared_from_this* __p)
    { return __p; }

    template<typename, _Lock_policy>
friend class __shared_ptr;

    mutable __weak_ptr<_Tp, _Lp>  _M_weak_this;
  };

template<typename _Tp, _Lock_policy _Lp, typename _Alloc, typename... _Args>
  inline __shared_ptr<_Tp, _Lp>
  __allocate_shared(const _Alloc& __a, _Args&&... __args)
  {
    return __shared_ptr<_Tp, _Lp>(_Sp_make_shared_tag(), __a,
		    std::forward<_Args>(__args)...);
  }

template<typename _Tp, _Lock_policy _Lp, typename... _Args>
  inline __shared_ptr<_Tp, _Lp>
  __make_shared(_Args&&... __args)
  {
    typedef typename std::remove_const<_Tp>::type _Tp_nc;
    return std::__allocate_shared<_Tp, _Lp>(std::allocator<_Tp_nc>(),
			      std::forward<_Args>(__args)...);
  }

/// std::hash specialization for __shared_ptr.
template<typename _Tp, _Lock_policy _Lp>
  struct hash<__shared_ptr<_Tp, _Lp>>
  : public __hash_base<size_t, __shared_ptr<_Tp, _Lp>>
  {
    size_t
    operator()(const __shared_ptr<_Tp, _Lp>& __s) const noexcept
    {
return hash<typename __shared_ptr<_Tp, _Lp>::element_type*>()(
   __s.get());
    }
  };

1863_GLIBCXX_END_NAMESPACE_VERSION
1864} // namespace

1866#endif // _SHARED_PTR_BASE_H