libstdc++-v3/include/bits/unique_ptr.h

   1 // unique_ptr implementation -*- C++ -*-
   2
   3 // Copyright (C) 2008-2018 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.
  10
  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.
  15
  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.
  19
  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/>.
  24
  25 /** @file bits/unique_ptr.h
  26  *  This is an internal header file, included by other library headers.
  27  *  Do not attempt to use it directly. @headername{memory}
  28  */
  29
  30 #ifndef _UNIQUE_PTR_H
  31 #define _UNIQUE_PTR_H 1
  32
  33 #include <bits/c++config.h>
  34 #include <debug/assertions.h>
  35 #include <type_traits>
  36 #include <utility>
  37 #include <tuple>
  38 #include <bits/stl_function.h>
  39 #include <bits/functional_hash.h>
  40
  41 namespace std _GLIBCXX_VISIBILITY(default)
  42 {
  43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  44
  45   /**
  46    * @addtogroup pointer_abstractions
  47    * @{
  48    */
  49
  50 #if _GLIBCXX_USE_DEPRECATED
  51 #pragma GCC diagnostic push
  52 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
  53   template<typename> class auto_ptr;
  54 #pragma GCC diagnostic pop
  55 #endif
  56
  57   /// Primary template of default_delete, used by unique_ptr
  58   template<typename _Tp>
  59     struct default_delete
  60     {
  61       /// Default constructor
  62       constexpr default_delete() noexcept = default;
  63
  64       /** @brief Converting constructor.
  65        *
  66        * Allows conversion from a deleter for arrays of another type, @p _Up,
  67        * only if @p _Up* is convertible to @p _Tp*.
  68        */
  69       template<typename _Up, typename = typename
  70                enable_if<is_convertible<_Up*, _Tp*>::value>::type>
  71         default_delete(const default_delete<_Up>&) noexcept { }
  72
  73       /// Calls @c delete @p __ptr
  74       void
  75       operator()(_Tp* __ptr) const
  76       {
  77         static_assert(!is_void<_Tp>::value,
  78                       "can't delete pointer to incomplete type");
  79         static_assert(sizeof(_Tp)>0,
  80                       "can't delete pointer to incomplete type");
  81         delete __ptr;
  82       }
  83     };
  84
  85   // _GLIBCXX_RESOLVE_LIB_DEFECTS
  86   // DR 740 - omit specialization for array objects with a compile time length
  87   /// Specialization for arrays, default_delete.
  88   template<typename _Tp>
  89     struct default_delete<_Tp[]>
  90     {
  91     public:
  92       /// Default constructor
  93       constexpr default_delete() noexcept = default;
  94
  95       /** @brief Converting constructor.
  96        *
  97        * Allows conversion from a deleter for arrays of another type, such as
  98        * a const-qualified version of @p _Tp.
  99        *
 100        * Conversions from types derived from @c _Tp are not allowed because
 101        * it is unsafe to @c delete[] an array of derived types through a
 102        * pointer to the base type.
 103        */
 104       template<typename _Up, typename = typename
 105                enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value>::type>
 106         default_delete(const default_delete<_Up[]>&) noexcept { }
 107
 108       /// Calls @c delete[] @p __ptr
 109       template<typename _Up>
 110       typename enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value>::type
 111         operator()(_Up* __ptr) const
 112       {
 113         static_assert(sizeof(_Tp)>0,
 114                       "can't delete pointer to incomplete type");
 115         delete [] __ptr;
 116       }
 117     };
 118
 119   template <typename _Tp, typename _Dp>
 120     class __uniq_ptr_impl
 121     {
 122       template <typename _Up, typename _Ep, typename = void>
 123         struct _Ptr
 124         {
 125           using type = _Up*;
 126         };
 127
 128       template <typename _Up, typename _Ep>
 129         struct
 130         _Ptr<_Up, _Ep, __void_t<typename remove_reference<_Ep>::type::pointer>>
 131         {
 132           using type = typename remove_reference<_Ep>::type::pointer;
 133         };
 134
 135     public:
 136       using _DeleterConstraint = enable_if<
 137         __and_<__not_<is_pointer<_Dp>>,
 138                is_default_constructible<_Dp>>::value>;
 139
 140       using pointer = typename _Ptr<_Tp, _Dp>::type;
 141
 142       __uniq_ptr_impl() = default;
 143       __uniq_ptr_impl(pointer __p) : _M_t() { _M_ptr() = __p; }
 144
 145       template<typename _Del>
 146       __uniq_ptr_impl(pointer __p, _Del&& __d)
 147         : _M_t(__p, std::forward<_Del>(__d)) { }
 148
 149       pointer&   _M_ptr() { return std::get<0>(_M_t); }
 150       pointer    _M_ptr() const { return std::get<0>(_M_t); }
 151       _Dp&       _M_deleter() { return std::get<1>(_M_t); }
 152       const _Dp& _M_deleter() const { return std::get<1>(_M_t); }
 153
 154     private:
 155       tuple<pointer, _Dp> _M_t;
 156     };
 157
 158   /// 20.7.1.2 unique_ptr for single objects.
 159   template <typename _Tp, typename _Dp = default_delete<_Tp>>
 160     class unique_ptr
 161     {
 162       template <class _Up>
 163       using _DeleterConstraint =
 164         typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type;
 165
 166       __uniq_ptr_impl<_Tp, _Dp> _M_t;
 167
 168     public:
 169       using pointer       = typename __uniq_ptr_impl<_Tp, _Dp>::pointer;
 170       using element_type  = _Tp;
 171       using deleter_type  = _Dp;
 172
 173       // helper template for detecting a safe conversion from another
 174       // unique_ptr
 175       template<typename _Up, typename _Ep>
 176         using __safe_conversion_up = __and_<
 177                 is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>,
 178                 __not_<is_array<_Up>>,
 179                 __or_<__and_<is_reference<deleter_type>,
 180                              is_same<deleter_type, _Ep>>,
 181                       __and_<__not_<is_reference<deleter_type>>,
 182                              is_convertible<_Ep, deleter_type>>
 183                 >
 184               >;
 185
 186       // Constructors.
 187
 188       /// Default constructor, creates a unique_ptr that owns nothing.
 189       template <typename _Up = _Dp,
 190                 typename = _DeleterConstraint<_Up>>
 191         constexpr unique_ptr() noexcept
 192         : _M_t()
 193         { }
 194
 195       /** Takes ownership of a pointer.
 196        *
 197        * @param __p  A pointer to an object of @c element_type
 198        *
 199        * The deleter will be value-initialized.
 200        */
 201       template <typename _Up = _Dp,
 202                 typename = _DeleterConstraint<_Up>>
 203         explicit
 204         unique_ptr(pointer __p) noexcept
 205         : _M_t(__p)
 206         { }
 207
 208       /** Takes ownership of a pointer.
 209        *
 210        * @param __p  A pointer to an object of @c element_type
 211        * @param __d  A reference to a deleter.
 212        *
 213        * The deleter will be initialized with @p __d
 214        */
 215       unique_ptr(pointer __p,
 216           typename conditional<is_reference<deleter_type>::value,
 217             deleter_type, const deleter_type&>::type __d) noexcept
 218       : _M_t(__p, __d) { }
 219
 220       /** Takes ownership of a pointer.
 221        *
 222        * @param __p  A pointer to an object of @c element_type
 223        * @param __d  An rvalue reference to a deleter.
 224        *
 225        * The deleter will be initialized with @p std::move(__d)
 226        */
 227       unique_ptr(pointer __p,
 228           typename remove_reference<deleter_type>::type&& __d) noexcept
 229       : _M_t(std::move(__p), std::move(__d))
 230       { static_assert(!std::is_reference<deleter_type>::value,
 231                       "rvalue deleter bound to reference"); }
 232
 233       /// Creates a unique_ptr that owns nothing.
 234       template <typename _Up = _Dp,
 235                 typename = _DeleterConstraint<_Up>>
 236         constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
 237
 238       // Move constructors.
 239
 240       /// Move constructor.
 241       unique_ptr(unique_ptr&& __u) noexcept
 242       : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
 243
 244       /** @brief Converting constructor from another type
 245        *
 246        * Requires that the pointer owned by @p __u is convertible to the
 247        * type of pointer owned by this object, @p __u does not own an array,
 248        * and @p __u has a compatible deleter type.
 249        */
 250       template<typename _Up, typename _Ep, typename = _Require<
 251                __safe_conversion_up<_Up, _Ep>,
 252                typename conditional<is_reference<_Dp>::value,
 253                                     is_same<_Ep, _Dp>,
 254                                     is_convertible<_Ep, _Dp>>::type>>
 255         unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
 256         : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))
 257         { }
 258
 259 #if _GLIBCXX_USE_DEPRECATED
 260 #pragma GCC diagnostic push
 261 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 262       /// Converting constructor from @c auto_ptr
 263       template<typename _Up, typename = _Require<
 264                is_convertible<_Up*, _Tp*>, is_same<_Dp, default_delete<_Tp>>>>
 265         unique_ptr(auto_ptr<_Up>&& __u) noexcept;
 266 #pragma GCC diagnostic pop
 267 #endif
 268
 269       /// Destructor, invokes the deleter if the stored pointer is not null.
 270       ~unique_ptr() noexcept
 271       {
 272         auto& __ptr = _M_t._M_ptr();
 273         if (__ptr != nullptr)
 274           get_deleter()(__ptr);
 275         __ptr = pointer();
 276       }
 277
 278       // Assignment.
 279
 280       /** @brief Move assignment operator.
 281        *
 282        * @param __u  The object to transfer ownership from.
 283        *
 284        * Invokes the deleter first if this object owns a pointer.
 285        */
 286       unique_ptr&
 287       operator=(unique_ptr&& __u) noexcept
 288       {
 289         reset(__u.release());
 290         get_deleter() = std::forward<deleter_type>(__u.get_deleter());
 291         return *this;
 292       }
 293
 294       /** @brief Assignment from another type.
 295        *
 296        * @param __u  The object to transfer ownership from, which owns a
 297        *             convertible pointer to a non-array object.
 298        *
 299        * Invokes the deleter first if this object owns a pointer.
 300        */
 301       template<typename _Up, typename _Ep>
 302         typename enable_if< __and_<
 303           __safe_conversion_up<_Up, _Ep>,
 304           is_assignable<deleter_type&, _Ep&&>
 305           >::value,
 306           unique_ptr&>::type
 307         operator=(unique_ptr<_Up, _Ep>&& __u) noexcept
 308         {
 309           reset(__u.release());
 310           get_deleter() = std::forward<_Ep>(__u.get_deleter());
 311           return *this;
 312         }
 313
 314       /// Reset the %unique_ptr to empty, invoking the deleter if necessary.
 315       unique_ptr&
 316       operator=(nullptr_t) noexcept
 317       {
 318         reset();
 319         return *this;
 320       }
 321
 322       // Observers.
 323
 324       /// Dereference the stored pointer.
 325       typename add_lvalue_reference<element_type>::type
 326       operator*() const
 327       {
 328         __glibcxx_assert(get() != pointer());
 329         return *get();
 330       }
 331
 332       /// Return the stored pointer.
 333       pointer
 334       operator->() const noexcept
 335       {
 336         _GLIBCXX_DEBUG_PEDASSERT(get() != pointer());
 337         return get();
 338       }
 339
 340       /// Return the stored pointer.
 341       pointer
 342       get() const noexcept
 343       { return _M_t._M_ptr(); }
 344
 345       /// Return a reference to the stored deleter.
 346       deleter_type&
 347       get_deleter() noexcept
 348       { return _M_t._M_deleter(); }
 349
 350       /// Return a reference to the stored deleter.
 351       const deleter_type&
 352       get_deleter() const noexcept
 353       { return _M_t._M_deleter(); }
 354
 355       /// Return @c true if the stored pointer is not null.
 356       explicit operator bool() const noexcept
 357       { return get() == pointer() ? false : true; }
 358
 359       // Modifiers.
 360
 361       /// Release ownership of any stored pointer.
 362       pointer
 363       release() noexcept
 364       {
 365         pointer __p = get();
 366         _M_t._M_ptr() = pointer();
 367         return __p;
 368       }
 369
 370       /** @brief Replace the stored pointer.
 371        *
 372        * @param __p  The new pointer to store.
 373        *
 374        * The deleter will be invoked if a pointer is already owned.
 375        */
 376       void
 377       reset(pointer __p = pointer()) noexcept
 378       {
 379         using std::swap;
 380         swap(_M_t._M_ptr(), __p);
 381         if (__p != pointer())
 382           get_deleter()(__p);
 383       }
 384
 385       /// Exchange the pointer and deleter with another object.
 386       void
 387       swap(unique_ptr& __u) noexcept
 388       {
 389         using std::swap;
 390         swap(_M_t, __u._M_t);
 391       }
 392
 393       // Disable copy from lvalue.
 394       unique_ptr(const unique_ptr&) = delete;
 395       unique_ptr& operator=(const unique_ptr&) = delete;
 396   };
 397
 398   /// 20.7.1.3 unique_ptr for array objects with a runtime length
 399   // [unique.ptr.runtime]
 400   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 401   // DR 740 - omit specialization for array objects with a compile time length
 402   template<typename _Tp, typename _Dp>
 403     class unique_ptr<_Tp[], _Dp>
 404     {
 405       template <typename _Up>
 406       using _DeleterConstraint =
 407         typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type;
 408
 409       __uniq_ptr_impl<_Tp, _Dp> _M_t;
 410
 411       template<typename _Up>
 412         using __remove_cv = typename remove_cv<_Up>::type;
 413
 414       // like is_base_of<_Tp, _Up> but false if unqualified types are the same
 415       template<typename _Up>
 416         using __is_derived_Tp
 417           = __and_< is_base_of<_Tp, _Up>,
 418                     __not_<is_same<__remove_cv<_Tp>, __remove_cv<_Up>>> >;
 419
 420     public:
 421       using pointer       = typename __uniq_ptr_impl<_Tp, _Dp>::pointer;
 422       using element_type  = _Tp;
 423       using deleter_type  = _Dp;
 424
 425       // helper template for detecting a safe conversion from another
 426       // unique_ptr
 427       template<typename _Up, typename _Ep,
 428                typename _Up_up = unique_ptr<_Up, _Ep>,
 429                typename _Up_element_type = typename _Up_up::element_type>
 430         using __safe_conversion_up = __and_<
 431           is_array<_Up>,
 432           is_same<pointer, element_type*>,
 433           is_same<typename _Up_up::pointer, _Up_element_type*>,
 434           is_convertible<_Up_element_type(*)[], element_type(*)[]>,
 435           __or_<__and_<is_reference<deleter_type>, is_same<deleter_type, _Ep>>,
 436                 __and_<__not_<is_reference<deleter_type>>,
 437                        is_convertible<_Ep, deleter_type>>>
 438         >;
 439
 440       // helper template for detecting a safe conversion from a raw pointer
 441       template<typename _Up>
 442         using __safe_conversion_raw = __and_<
 443           __or_<__or_<is_same<_Up, pointer>,
 444                       is_same<_Up, nullptr_t>>,
 445                 __and_<is_pointer<_Up>,
 446                        is_same<pointer, element_type*>,
 447                        is_convertible<
 448                          typename remove_pointer<_Up>::type(*)[],
 449                          element_type(*)[]>
 450                 >
 451           >
 452         >;
 453
 454       // Constructors.
 455
 456       /// Default constructor, creates a unique_ptr that owns nothing.
 457       template <typename _Up = _Dp,
 458                 typename = _DeleterConstraint<_Up>>
 459         constexpr unique_ptr() noexcept
 460         : _M_t()
 461         { }
 462
 463       /** Takes ownership of a pointer.
 464        *
 465        * @param __p  A pointer to an array of a type safely convertible
 466        * to an array of @c element_type
 467        *
 468        * The deleter will be value-initialized.
 469        */
 470       template<typename _Up,
 471                typename _Vp = _Dp,
 472                typename = _DeleterConstraint<_Vp>,
 473                typename = typename enable_if<
 474                  __safe_conversion_raw<_Up>::value, bool>::type>
 475         explicit
 476         unique_ptr(_Up __p) noexcept
 477         : _M_t(__p)
 478         { }
 479
 480       /** Takes ownership of a pointer.
 481        *
 482        * @param __p  A pointer to an array of a type safely convertible
 483        * to an array of @c element_type
 484        * @param __d  A reference to a deleter.
 485        *
 486        * The deleter will be initialized with @p __d
 487        */
 488       template<typename _Up,
 489                typename = typename enable_if<
 490                  __safe_conversion_raw<_Up>::value, bool>::type>
 491       unique_ptr(_Up __p,
 492                  typename conditional<is_reference<deleter_type>::value,
 493                  deleter_type, const deleter_type&>::type __d) noexcept
 494       : _M_t(__p, __d) { }
 495
 496       /** Takes ownership of a pointer.
 497        *
 498        * @param __p  A pointer to an array of a type safely convertible
 499        * to an array of @c element_type
 500        * @param __d  A reference to a deleter.
 501        *
 502        * The deleter will be initialized with @p std::move(__d)
 503        */
 504       template<typename _Up,
 505                typename = typename enable_if<
 506                  __safe_conversion_raw<_Up>::value, bool>::type>
 507       unique_ptr(_Up __p, typename
 508                  remove_reference<deleter_type>::type&& __d) noexcept
 509       : _M_t(std::move(__p), std::move(__d))
 510       { static_assert(!is_reference<deleter_type>::value,
 511                       "rvalue deleter bound to reference"); }
 512
 513       /// Move constructor.
 514       unique_ptr(unique_ptr&& __u) noexcept
 515       : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
 516
 517       /// Creates a unique_ptr that owns nothing.
 518       template <typename _Up = _Dp,
 519                 typename = _DeleterConstraint<_Up>>
 520         constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
 521
 522       template<typename _Up, typename _Ep,
 523                typename = _Require<__safe_conversion_up<_Up, _Ep>>>
 524         unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
 525         : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))
 526         { }
 527
 528       /// Destructor, invokes the deleter if the stored pointer is not null.
 529       ~unique_ptr()
 530       {
 531         auto& __ptr = _M_t._M_ptr();
 532         if (__ptr != nullptr)
 533           get_deleter()(__ptr);
 534         __ptr = pointer();
 535       }
 536
 537       // Assignment.
 538
 539       /** @brief Move assignment operator.
 540        *
 541        * @param __u  The object to transfer ownership from.
 542        *
 543        * Invokes the deleter first if this object owns a pointer.
 544        */
 545       unique_ptr&
 546       operator=(unique_ptr&& __u) noexcept
 547       {
 548         reset(__u.release());
 549         get_deleter() = std::forward<deleter_type>(__u.get_deleter());
 550         return *this;
 551       }
 552
 553       /** @brief Assignment from another type.
 554        *
 555        * @param __u  The object to transfer ownership from, which owns a
 556        *             convertible pointer to an array object.
 557        *
 558        * Invokes the deleter first if this object owns a pointer.
 559        */
 560       template<typename _Up, typename _Ep>
 561         typename
 562         enable_if<__and_<__safe_conversion_up<_Up, _Ep>,
 563                          is_assignable<deleter_type&, _Ep&&>
 564                   >::value,
 565                   unique_ptr&>::type
 566         operator=(unique_ptr<_Up, _Ep>&& __u) noexcept
 567         {
 568           reset(__u.release());
 569           get_deleter() = std::forward<_Ep>(__u.get_deleter());
 570           return *this;
 571         }
 572
 573       /// Reset the %unique_ptr to empty, invoking the deleter if necessary.
 574       unique_ptr&
 575       operator=(nullptr_t) noexcept
 576       {
 577         reset();
 578         return *this;
 579       }
 580
 581       // Observers.
 582
 583       /// Access an element of owned array.
 584       typename std::add_lvalue_reference<element_type>::type
 585       operator[](size_t __i) const
 586       {
 587         __glibcxx_assert(get() != pointer());
 588         return get()[__i];
 589       }
 590
 591       /// Return the stored pointer.
 592       pointer
 593       get() const noexcept
 594       { return _M_t._M_ptr(); }
 595
 596       /// Return a reference to the stored deleter.
 597       deleter_type&
 598       get_deleter() noexcept
 599       { return _M_t._M_deleter(); }
 600
 601       /// Return a reference to the stored deleter.
 602       const deleter_type&
 603       get_deleter() const noexcept
 604       { return _M_t._M_deleter(); }
 605
 606       /// Return @c true if the stored pointer is not null.
 607       explicit operator bool() const noexcept
 608       { return get() == pointer() ? false : true; }
 609
 610       // Modifiers.
 611
 612       /// Release ownership of any stored pointer.
 613       pointer
 614       release() noexcept
 615       {
 616         pointer __p = get();
 617         _M_t._M_ptr() = pointer();
 618         return __p;
 619       }
 620
 621       /** @brief Replace the stored pointer.
 622        *
 623        * @param __p  The new pointer to store.
 624        *
 625        * The deleter will be invoked if a pointer is already owned.
 626        */
 627       template <typename _Up,
 628                 typename = _Require<
 629                   __or_<is_same<_Up, pointer>,
 630                         __and_<is_same<pointer, element_type*>,
 631                                is_pointer<_Up>,
 632                                is_convertible<
 633                                  typename remove_pointer<_Up>::type(*)[],
 634                                  element_type(*)[]
 635                                >
 636                         >
 637                   >
 638                >>
 639       void
 640       reset(_Up __p) noexcept
 641       {
 642         pointer __ptr = __p;
 643         using std::swap;
 644         swap(_M_t._M_ptr(), __ptr);
 645         if (__ptr != nullptr)
 646           get_deleter()(__ptr);
 647       }
 648
 649       void reset(nullptr_t = nullptr) noexcept
 650       {
 651         reset(pointer());
 652       }
 653
 654       /// Exchange the pointer and deleter with another object.
 655       void
 656       swap(unique_ptr& __u) noexcept
 657       {
 658         using std::swap;
 659         swap(_M_t, __u._M_t);
 660       }
 661
 662       // Disable copy from lvalue.
 663       unique_ptr(const unique_ptr&) = delete;
 664       unique_ptr& operator=(const unique_ptr&) = delete;
 665     };
 666
 667   template<typename _Tp, typename _Dp>
 668     inline
 669 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
 670     // Constrained free swap overload, see p0185r1
 671     typename enable_if<__is_swappable<_Dp>::value>::type
 672 #else
 673     void
 674 #endif
 675     swap(unique_ptr<_Tp, _Dp>& __x,
 676          unique_ptr<_Tp, _Dp>& __y) noexcept
 677     { __x.swap(__y); }
 678
 679 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
 680   template<typename _Tp, typename _Dp>
 681     typename enable_if<!__is_swappable<_Dp>::value>::type
 682     swap(unique_ptr<_Tp, _Dp>&,
 683          unique_ptr<_Tp, _Dp>&) = delete;
 684 #endif
 685
 686   template<typename _Tp, typename _Dp,
 687            typename _Up, typename _Ep>
 688     inline bool
 689     operator==(const unique_ptr<_Tp, _Dp>& __x,
 690                const unique_ptr<_Up, _Ep>& __y)
 691     { return __x.get() == __y.get(); }
 692
 693   template<typename _Tp, typename _Dp>
 694     inline bool
 695     operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
 696     { return !__x; }
 697
 698   template<typename _Tp, typename _Dp>
 699     inline bool
 700     operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
 701     { return !__x; }
 702
 703   template<typename _Tp, typename _Dp,
 704            typename _Up, typename _Ep>
 705     inline bool
 706     operator!=(const unique_ptr<_Tp, _Dp>& __x,
 707                const unique_ptr<_Up, _Ep>& __y)
 708     { return __x.get() != __y.get(); }
 709
 710   template<typename _Tp, typename _Dp>
 711     inline bool
 712     operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
 713     { return (bool)__x; }
 714
 715   template<typename _Tp, typename _Dp>
 716     inline bool
 717     operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
 718     { return (bool)__x; }
 719
 720   template<typename _Tp, typename _Dp,
 721            typename _Up, typename _Ep>
 722     inline bool
 723     operator<(const unique_ptr<_Tp, _Dp>& __x,
 724               const unique_ptr<_Up, _Ep>& __y)
 725     {
 726       typedef typename
 727         std::common_type<typename unique_ptr<_Tp, _Dp>::pointer,
 728                          typename unique_ptr<_Up, _Ep>::pointer>::type _CT;
 729       return std::less<_CT>()(__x.get(), __y.get());
 730     }
 731
 732   template<typename _Tp, typename _Dp>
 733     inline bool
 734     operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
 735     { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(),
 736                                                                  nullptr); }
 737
 738   template<typename _Tp, typename _Dp>
 739     inline bool
 740     operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
 741     { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr,
 742                                                                  __x.get()); }
 743
 744   template<typename _Tp, typename _Dp,
 745            typename _Up, typename _Ep>
 746     inline bool
 747     operator<=(const unique_ptr<_Tp, _Dp>& __x,
 748                const unique_ptr<_Up, _Ep>& __y)
 749     { return !(__y < __x); }
 750
 751   template<typename _Tp, typename _Dp>
 752     inline bool
 753     operator<=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
 754     { return !(nullptr < __x); }
 755
 756   template<typename _Tp, typename _Dp>
 757     inline bool
 758     operator<=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
 759     { return !(__x < nullptr); }
 760
 761   template<typename _Tp, typename _Dp,
 762            typename _Up, typename _Ep>
 763     inline bool
 764     operator>(const unique_ptr<_Tp, _Dp>& __x,
 765               const unique_ptr<_Up, _Ep>& __y)
 766     { return (__y < __x); }
 767
 768   template<typename _Tp, typename _Dp>
 769     inline bool
 770     operator>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
 771     { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr,
 772                                                                  __x.get()); }
 773
 774   template<typename _Tp, typename _Dp>
 775     inline bool
 776     operator>(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
 777     { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(),
 778                                                                  nullptr); }
 779
 780   template<typename _Tp, typename _Dp,
 781            typename _Up, typename _Ep>
 782     inline bool
 783     operator>=(const unique_ptr<_Tp, _Dp>& __x,
 784                const unique_ptr<_Up, _Ep>& __y)
 785     { return !(__x < __y); }
 786
 787   template<typename _Tp, typename _Dp>
 788     inline bool
 789     operator>=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
 790     { return !(__x < nullptr); }
 791
 792   template<typename _Tp, typename _Dp>
 793     inline bool
 794     operator>=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
 795     { return !(nullptr < __x); }
 796
 797   /// std::hash specialization for unique_ptr.
 798   template<typename _Tp, typename _Dp>
 799     struct hash<unique_ptr<_Tp, _Dp>>
 800     : public __hash_base<size_t, unique_ptr<_Tp, _Dp>>,
 801     private __poison_hash<typename unique_ptr<_Tp, _Dp>::pointer>
 802     {
 803       size_t
 804       operator()(const unique_ptr<_Tp, _Dp>& __u) const noexcept
 805       {
 806         typedef unique_ptr<_Tp, _Dp> _UP;
 807         return std::hash<typename _UP::pointer>()(__u.get());
 808       }
 809     };
 810
 811 #if __cplusplus > 201103L
 812
 813 #define __cpp_lib_make_unique 201304
 814
 815   template<typename _Tp>
 816     struct _MakeUniq
 817     { typedef unique_ptr<_Tp> __single_object; };
 818
 819   template<typename _Tp>
 820     struct _MakeUniq<_Tp[]>
 821     { typedef unique_ptr<_Tp[]> __array; };
 822
 823   template<typename _Tp, size_t _Bound>
 824     struct _MakeUniq<_Tp[_Bound]>
 825     { struct __invalid_type { }; };
 826
 827   /// std::make_unique for single objects
 828   template<typename _Tp, typename... _Args>
 829     inline typename _MakeUniq<_Tp>::__single_object
 830     make_unique(_Args&&... __args)
 831     { return unique_ptr<_Tp>(new _Tp(std::forward<_Args>(__args)...)); }
 832
 833   /// std::make_unique for arrays of unknown bound
 834   template<typename _Tp>
 835     inline typename _MakeUniq<_Tp>::__array
 836     make_unique(size_t __num)
 837     { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__num]()); }
 838
 839   /// Disable std::make_unique for arrays of known bound
 840   template<typename _Tp, typename... _Args>
 841     inline typename _MakeUniq<_Tp>::__invalid_type
 842     make_unique(_Args&&...) = delete;
 843 #endif
 844
 845   // @} group pointer_abstractions
 846
 847 _GLIBCXX_END_NAMESPACE_VERSION
 848 } // namespace
 849
 850 #endif /* _UNIQUE_PTR_H */