# unique_ptr.h

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    00001 // unique_ptr implementation -*- C++ -*-
    00002
    00003 // Copyright (C) 2008, 2009 Free Software Foundation, Inc.
    00004 //
    00005 // This file is part of the GNU ISO C++ Library.  This library is free
    00006 // software; you can redistribute it and/or modify it under the
    00007 // terms of the GNU General Public License as published by the
    00008 // Free Software Foundation; either version 3, or (at your option)
    00009 // any later version.
    00010
    00011 // This library is distributed in the hope that it will be useful,
    00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00014 // GNU General Public License for more details.
    00015
    00016 // Under Section 7 of GPL version 3, you are granted additional
    00017 // permissions described in the GCC Runtime Library Exception, version
    00018 // 3.1, as published by the Free Software Foundation.
    00019
    00020 // You should have received a copy of the GNU General Public License and
    00021 // a copy of the GCC Runtime Library Exception along with this program;
    00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
    00023 // <http://www.gnu.org/licenses/>.
    00024
    00025 /** @file unique_ptr.h
    00026  *  This is an internal header file, included by other library headers.
    00027  *  You should not attempt to use it directly.
    00028  */
    00029
    00030 #ifndef _UNIQUE_PTR_H
    00031 #define _UNIQUE_PTR_H 1
    00032
    00033 #ifndef __GXX_EXPERIMENTAL_CXX0X__
    00034 # include <c++0x_warning.h>
    00035 #endif
    00036
    00037 #include <bits/c++config.h>
    00038 #include <debug/debug.h>
    00039 #include <type_traits>
    00040 #include <utility>
    00041 #include <tuple>
    00042
    00043 _GLIBCXX_BEGIN_NAMESPACE(std)
    00044
    00045   /**
    00046    * @addtogroup pointer_abstractions
    00047    * @{
    00048    */
    00049
    00050   /// Primary template, default_delete.
    00051   template<typename _Tp>
    00052     struct default_delete
    00053       {
    00054     default_delete() { }
    00055
    00056     template<typename _Up>
    00057       default_delete(const default_delete<_Up>&) { }
    00058
    00059     void
    00060     operator()(_Tp* __ptr) const
    00061     {
    00062       static_assert(sizeof(_Tp)>0,
    00063             "can't delete pointer to incomplete type");
    00064       delete __ptr;
    00065     }
    00066     };
    00067
    00068   // _GLIBCXX_RESOLVE_LIB_DEFECTS
    00069   // DR 740 - omit specialization for array objects with a compile time length
    00070   /// Specialization, default_delete.
    00071   template<typename _Tp>
    00072     struct default_delete<_Tp[]>
    00073     {
    00074       void
    00075       operator()(_Tp* __ptr) const
    00076       {
    00077     static_assert(sizeof(_Tp)>0,
    00078               "can't delete pointer to incomplete type");
    00079     delete [] __ptr;
    00080       }
    00081     };
    00082
    00083   /// 20.7.12.2 unique_ptr for single objects.
    00084   template <typename _Tp, typename _Tp_Deleter = default_delete<_Tp> >
    00085     class unique_ptr
    00086     {
    00087       typedef std::tuple<_Tp*, _Tp_Deleter>  __tuple_type;
    00088       typedef __tuple_type unique_ptr::*     __unspecified_bool_type;
    00089       typedef _Tp* unique_ptr::*             __unspecified_pointer_type;
    00090
    00091     public:
    00092       typedef _Tp*               pointer;
    00093       typedef _Tp                element_type;
    00094       typedef _Tp_Deleter        deleter_type;
    00095
    00096       // Constructors.
    00097       unique_ptr()
    00098       : _M_t(pointer(), deleter_type())
    00099       { static_assert(!std::is_pointer<deleter_type>::value,
    00100               "constructed with null function pointer deleter"); }
    00101
    00102       explicit
    00103       unique_ptr(pointer __p)
    00104       : _M_t(__p, deleter_type())
    00105       { static_assert(!std::is_pointer<deleter_type>::value,
    00106              "constructed with null function pointer deleter"); }
    00107
    00108       unique_ptr(pointer __p,
    00109           typename std::conditional<std::is_reference<deleter_type>::value,
    00110             deleter_type, const deleter_type&>::type __d)
    00111       : _M_t(__p, __d) { }
    00112
    00113       unique_ptr(pointer __p,
    00114           typename std::remove_reference<deleter_type>::type&& __d)
    00115       : _M_t(std::move(__p), std::move(__d))
    00116       { static_assert(!std::is_reference<deleter_type>::value,
    00117               "rvalue deleter bound to reference"); }
    00118
    00119       // Move constructors.
    00120       unique_ptr(unique_ptr&& __u)
    00121       : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
    00122
    00123       template<typename _Up, typename _Up_Deleter>
    00124         unique_ptr(unique_ptr<_Up, _Up_Deleter>&& __u)
    00125         : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter()))
    00126     { }
    00127
    00128       // Destructor.
    00129       ~unique_ptr() { reset(); }
    00130
    00131       // Assignment.
    00132       unique_ptr&
    00133       operator=(unique_ptr&& __u)
    00134       {
    00135         reset(__u.release());
    00136         get_deleter() = std::move(__u.get_deleter());
    00137         return *this;
    00138       }
    00139
    00140       template<typename _Up, typename _Up_Deleter>
    00141         unique_ptr&
    00142         operator=(unique_ptr<_Up, _Up_Deleter>&& __u)
    00143     {
    00144           reset(__u.release());
    00145           get_deleter() = std::move(__u.get_deleter());
    00146           return *this;
    00147         }
    00148
    00149       unique_ptr&
    00150       operator=(__unspecified_pointer_type)
    00151       {
    00152     reset();
    00153     return *this;
    00154       }
    00155
    00156       // Observers.
    00157       typename std::add_lvalue_reference<element_type>::type operator*() const
    00158       {
    00159     _GLIBCXX_DEBUG_ASSERT(get() != 0);
    00160     return *get();
    00161       }
    00162
    00163       pointer
    00164       operator->() const
    00165       {
    00166     _GLIBCXX_DEBUG_ASSERT(get() != 0);
    00167     return get();
    00168       }
    00169
    00170       pointer
    00171       get() const
    00172       { return std::get<0>(_M_t); }
    00173
    00174       typename std::add_lvalue_reference<deleter_type>::type
    00175       get_deleter()
    00176       { return std::get<1>(_M_t); }
    00177
    00178       typename std::add_lvalue_reference<
    00179           typename std::add_const<deleter_type>::type
    00180               >::type
    00181       get_deleter() const
    00182       { return std::get<1>(_M_t); }
    00183
    00184       operator __unspecified_bool_type () const
    00185       { return get() == 0 ? 0 : &unique_ptr::_M_t; }
    00186
    00187       // Modifiers.
    00188       pointer
    00189       release()
    00190       {
    00191     pointer __p = get();
    00192     std::get<0>(_M_t) = 0;
    00193     return __p;
    00194       }
    00195
    00196       void
    00197       reset(pointer __p = pointer())
    00198       {
    00199     if (__p != get())
    00200       {
    00201         get_deleter()(get());
    00202         std::get<0>(_M_t) = __p;
    00203       }
    00204       }
    00205
    00206       void
    00207       swap(unique_ptr&& __u)
    00208       {
    00209     using std::swap;
    00210     swap(_M_t, __u._M_t);
    00211       }
    00212
    00213       // Disable copy from lvalue.
    00214       unique_ptr(const unique_ptr&) = delete;
    00215
    00216       template<typename _Up, typename _Up_Deleter>
    00217         unique_ptr(const unique_ptr<_Up, _Up_Deleter>&) = delete;
    00218
    00219       unique_ptr& operator=(const unique_ptr&) = delete;
    00220
    00221       template<typename _Up, typename _Up_Deleter>
    00222         unique_ptr& operator=(const unique_ptr<_Up, _Up_Deleter>&) = delete;
    00223
    00224     private:
    00225       __tuple_type _M_t;
    00226   };
    00227
    00228   /// 20.7.12.3 unique_ptr for array objects with a runtime length
    00229   // [unique.ptr.runtime]
    00230   // _GLIBCXX_RESOLVE_LIB_DEFECTS
    00231   // DR 740 - omit specialization for array objects with a compile time length
    00232   template<typename _Tp, typename _Tp_Deleter>
    00233     class unique_ptr<_Tp[], _Tp_Deleter>
    00234     {
    00235       typedef std::tuple<_Tp*, _Tp_Deleter>  __tuple_type;
    00236       typedef __tuple_type unique_ptr::*     __unspecified_bool_type;
    00237       typedef _Tp* unique_ptr::*             __unspecified_pointer_type;
    00238
    00239     public:
    00240       typedef _Tp*               pointer;
    00241       typedef _Tp                element_type;
    00242       typedef _Tp_Deleter        deleter_type;
    00243
    00244       // Constructors.
    00245       unique_ptr()
    00246       : _M_t(pointer(), deleter_type())
    00247       { static_assert(!std::is_pointer<deleter_type>::value,
    00248               "constructed with null function pointer deleter"); }
    00249
    00250       explicit
    00251       unique_ptr(pointer __p)
    00252       : _M_t(__p, deleter_type())
    00253       { static_assert(!std::is_pointer<deleter_type>::value,
    00254               "constructed with null function pointer deleter"); }
    00255
    00256       unique_ptr(pointer __p,
    00257           typename std::conditional<std::is_reference<deleter_type>::value,
    00258               deleter_type, const deleter_type&>::type __d)
    00259       : _M_t(__p, __d) { }
    00260
    00261       unique_ptr(pointer __p,
    00262          typename std::remove_reference<deleter_type>::type && __d)
    00263       : _M_t(std::move(__p), std::move(__d))
    00264       { static_assert(!std::is_reference<deleter_type>::value,
    00265               "rvalue deleter bound to reference"); }
    00266
    00267       // Move constructors.
    00268       unique_ptr(unique_ptr&& __u)
    00269       : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
    00270
    00271       template<typename _Up, typename _Up_Deleter>
    00272         unique_ptr(unique_ptr<_Up, _Up_Deleter>&& __u)
    00273     : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter()))
    00274     { }
    00275
    00276       // Destructor.
    00277       ~unique_ptr() { reset(); }
    00278
    00279       // Assignment.
    00280       unique_ptr&
    00281       operator=(unique_ptr&& __u)
    00282       {
    00283     reset(__u.release());
    00284     get_deleter() = std::move(__u.get_deleter());
    00285     return *this;
    00286       }
    00287
    00288       template<typename _Up, typename _Up_Deleter>
    00289         unique_ptr&
    00290         operator=(unique_ptr<_Up, _Up_Deleter>&& __u)
    00291     {
    00292           reset(__u.release());
    00293           get_deleter() = std::move(__u.get_deleter());
    00294           return *this;
    00295         }
    00296
    00297       unique_ptr&
    00298       operator=(__unspecified_pointer_type)
    00299       {
    00300     reset();
    00301     return *this;
    00302       }
    00303
    00304       // Observers.
    00305       typename std::add_lvalue_reference<element_type>::type
    00306       operator[](size_t __i) const
    00307       {
    00308     _GLIBCXX_DEBUG_ASSERT(get() != 0);
    00309     return get()[__i];
    00310       }
    00311
    00312       pointer
    00313       get() const
    00314       { return std::get<0>(_M_t); }
    00315
    00316       typename std::add_lvalue_reference<deleter_type>::type
    00317       get_deleter()
    00318       { return std::get<1>(_M_t); }
    00319
    00320       typename std::add_lvalue_reference<
    00321           typename std::add_const<deleter_type>::type
    00322               >::type
    00323       get_deleter() const
    00324       { return std::get<1>(_M_t); }
    00325
    00326       operator __unspecified_bool_type () const
    00327       { return get() == 0 ? 0 : &unique_ptr::_M_t; }
    00328
    00329       // Modifiers.
    00330       pointer
    00331       release()
    00332       {
    00333     pointer __p = get();
    00334     std::get<0>(_M_t) = 0;
    00335     return __p;
    00336       }
    00337
    00338       void
    00339       reset(pointer __p = pointer())
    00340       {
    00341     if (__p != get())
    00342     {
    00343       get_deleter()(get());
    00344       std::get<0>(_M_t) = __p;
    00345     }
    00346       }
    00347
    00348       // DR 821.
    00349       template<typename _Up>
    00350         void reset(_Up) = delete;
    00351
    00352       void
    00353       swap(unique_ptr&& __u)
    00354       {
    00355     using std::swap;
    00356     swap(_M_t, __u._M_t);
    00357       }
    00358
    00359       // Disable copy from lvalue.
    00360       unique_ptr(const unique_ptr&) = delete;
    00361       unique_ptr& operator=(const unique_ptr&) = delete;
    00362
    00363       // Disable construction from convertible pointer types.
    00364       // (N2315 - 20.6.5.3.1)
    00365       template<typename _Up>
    00366         unique_ptr(_Up*, typename
    00367            std::conditional<std::is_reference<deleter_type>::value,
    00368            deleter_type, const deleter_type&>::type,
    00369            typename std::enable_if<std::is_convertible<_Up*,
    00370            pointer>::value>::type* = 0) = delete;
    00371
    00372       template<typename _Up>
    00373         unique_ptr(_Up*, typename std::remove_reference<deleter_type>::type&&,
    00374            typename std::enable_if<std::is_convertible<_Up*,
    00375            pointer>::value>::type* = 0) = delete;
    00376
    00377       template<typename _Up>
    00378         explicit
    00379         unique_ptr(_Up*, typename std::enable_if<std::is_convertible<_Up*,
    00380            pointer>::value>::type* = 0) = delete;
    00381
    00382     private:
    00383       __tuple_type _M_t;
    00384   };
    00385
    00386   template<typename _Tp, typename _Tp_Deleter>
    00387     inline void
    00388     swap(unique_ptr<_Tp, _Tp_Deleter>& __x,
    00389      unique_ptr<_Tp, _Tp_Deleter>& __y)
    00390     { __x.swap(__y); }
    00391
    00392   template<typename _Tp, typename _Tp_Deleter>
    00393     inline void
    00394     swap(unique_ptr<_Tp, _Tp_Deleter>&& __x,
    00395      unique_ptr<_Tp, _Tp_Deleter>& __y)
    00396     { __x.swap(__y); }
    00397
    00398   template<typename _Tp, typename _Tp_Deleter>
    00399     inline void
    00400     swap(unique_ptr<_Tp, _Tp_Deleter>& __x,
    00401      unique_ptr<_Tp, _Tp_Deleter>&& __y)
    00402     { __x.swap(__y); }
    00403
    00404   template<typename _Tp, typename _Tp_Deleter,
    00405        typename _Up, typename _Up_Deleter>
    00406     inline bool
    00407     operator==(const unique_ptr<_Tp, _Tp_Deleter>& __x,
    00408            const unique_ptr<_Up, _Up_Deleter>& __y)
    00409     { return __x.get() == __y.get(); }
    00410
    00411   template<typename _Tp, typename _Tp_Deleter,
    00412        typename _Up, typename _Up_Deleter>
    00413     inline bool
    00414     operator!=(const unique_ptr<_Tp, _Tp_Deleter>& __x,
    00415            const unique_ptr<_Up, _Up_Deleter>& __y)
    00416     { return !(__x.get() == __y.get()); }
    00417
    00418   template<typename _Tp, typename _Tp_Deleter,
    00419        typename _Up, typename _Up_Deleter>
    00420     inline bool
    00421     operator<(const unique_ptr<_Tp, _Tp_Deleter>& __x,
    00422           const unique_ptr<_Up, _Up_Deleter>& __y)
    00423     { return __x.get() < __y.get(); }
    00424
    00425   template<typename _Tp, typename _Tp_Deleter,
    00426        typename _Up, typename _Up_Deleter>
    00427     inline bool
    00428     operator<=(const unique_ptr<_Tp, _Tp_Deleter>& __x,
    00429            const unique_ptr<_Up, _Up_Deleter>& __y)
    00430     { return !(__y.get() < __x.get()); }
    00431
    00432   template<typename _Tp, typename _Tp_Deleter,
    00433        typename _Up, typename _Up_Deleter>
    00434     inline bool
    00435     operator>(const unique_ptr<_Tp, _Tp_Deleter>& __x,
    00436           const unique_ptr<_Up, _Up_Deleter>& __y)
    00437     { return __y.get() < __x.get(); }
    00438
    00439   template<typename _Tp, typename _Tp_Deleter,
    00440        typename _Up, typename _Up_Deleter>
    00441     inline bool
    00442     operator>=(const unique_ptr<_Tp, _Tp_Deleter>& __x,
    00443            const unique_ptr<_Up, _Up_Deleter>& __y)
    00444     { return !(__x.get() < __y.get()); }
    00445
    00446   // @} group pointer_abstractions
    00447
    00448 _GLIBCXX_END_NAMESPACE
    00449
    00450 #endif /* _UNIQUE_PTR_H */