boost/serialization/detail/shared_ptr_132.hpp

   1 #ifndef BOOST_SHARED_PTR_132_HPP_INCLUDED
   2 #define BOOST_SHARED_PTR_132_HPP_INCLUDED
   3
   4 //
   5 //  shared_ptr.hpp
   6 //
   7 //  (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
   8 //  Copyright (c) 2001, 2002, 2003 Peter Dimov
   9 //
  10 //  Distributed under the Boost Software License, Version 1.0. (See
  11 //  accompanying file LICENSE_1_0.txt or copy at
  12 //  http://www.boost.org/LICENSE_1_0.txt)
  13 //
  14 //  See http://www.boost.org/libs/smart_ptr/shared_ptr.htm for documentation.
  15 //
  16
  17 #include <boost/config.hpp>   // for broken compiler workarounds
  18
  19 #if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)
  20 #include <boost/serialization/detail/shared_ptr_nmt_132.hpp>
  21 #else
  22
  23 #include <boost/assert.hpp>
  24 #include <boost/checked_delete.hpp>
  25 #include <boost/serialization/throw_exception.hpp>
  26 #include <boost/detail/workaround.hpp>
  27
  28 #include <boost/serialization/access.hpp>
  29 #include <boost/serialization/detail/shared_count_132.hpp>
  30
  31 #include <memory>               // for std::auto_ptr
  32 #include <algorithm>            // for std::swap
  33 #include <functional>           // for std::less
  34 #include <typeinfo>             // for std::bad_cast
  35 #include <iosfwd>               // for std::basic_ostream
  36
  37 #ifdef BOOST_MSVC  // moved here to work around VC++ compiler crash
  38 # pragma warning(push)
  39 # pragma warning(disable:4284) // odd return type for operator->
  40 #endif
  41
  42 namespace boost_132 {
  43
  44 template<class T> class weak_ptr;
  45 template<class T> class enable_shared_from_this;
  46
  47 namespace detail
  48 {
  49
  50 struct static_cast_tag {};
  51 struct const_cast_tag {};
  52 struct dynamic_cast_tag {};
  53 struct polymorphic_cast_tag {};
  54
  55 template<class T> struct shared_ptr_traits
  56 {
  57     typedef T & reference;
  58 };
  59
  60 template<> struct shared_ptr_traits<void>
  61 {
  62     typedef void reference;
  63 };
  64
  65 #if !defined(BOOST_NO_CV_VOID_SPECIALIZATIONS)
  66
  67 template<> struct shared_ptr_traits<void const>
  68 {
  69     typedef void reference;
  70 };
  71
  72 template<> struct shared_ptr_traits<void volatile>
  73 {
  74     typedef void reference;
  75 };
  76
  77 template<> struct shared_ptr_traits<void const volatile>
  78 {
  79     typedef void reference;
  80 };
  81
  82 #endif
  83
  84 // enable_shared_from_this support
  85
  86 template<class T, class Y> void sp_enable_shared_from_this( shared_count const & pn, enable_shared_from_this<T> const * pe, Y const * px )
  87 {
  88     if(pe != 0) pe->_internal_weak_this._internal_assign(const_cast<Y*>(px), pn);
  89 }
  90
  91 inline void sp_enable_shared_from_this( shared_count const & /*pn*/, ... )
  92 {
  93 }
  94
  95 } // namespace detail
  96
  97
  98 //
  99 //  shared_ptr
 100 //
 101 //  An enhanced relative of scoped_ptr with reference counted copy semantics.
 102 //  The object pointed to is deleted when the last shared_ptr pointing to it
 103 //  is destroyed or reset.
 104 //
 105
 106 template<class T> class shared_ptr
 107 {
 108 private:
 109     // Borland 5.5.1 specific workaround
 110     typedef shared_ptr<T> this_type;
 111
 112 public:
 113
 114     typedef T element_type;
 115     typedef T value_type;
 116     typedef T * pointer;
 117     typedef BOOST_DEDUCED_TYPENAME detail::shared_ptr_traits<T>::reference reference;
 118
 119     shared_ptr(): px(0), pn() // never throws in 1.30+
 120     {
 121     }
 122
 123 #if BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT( 0x564) )
 124     template<class Y>
 125     explicit shared_ptr(Y * p): px(p), pn(p, boost::checked_deleter<Y>()) // Y must be complete
 126 #else
 127     template<class Y>
 128     explicit shared_ptr(Y * p): px(p), pn(p, boost::checked_deleter<Y>()) // Y must be complete
 129 #endif
 130     {
 131         detail::sp_enable_shared_from_this( pn, p, p );
 132     }
 133
 134     //
 135     // Requirements: D's copy constructor must not throw
 136     //
 137     // shared_ptr will release p by calling d(p)
 138     //
 139
 140     template<class Y, class D> shared_ptr(Y * p, D d): px(p), pn(p, d)
 141     {
 142         detail::sp_enable_shared_from_this( pn, p, p );
 143     }
 144
 145 //  generated copy constructor, assignment, destructor are fine...
 146
 147 //  except that Borland C++ has a bug, and g++ with -Wsynth warns
 148 #if defined(__BORLANDC__) || defined(__GNUC__)
 149
 150     shared_ptr & operator=(shared_ptr const & r) // never throws
 151     {
 152         px = r.px;
 153         pn = r.pn; // shared_count::op= doesn't throw
 154         return *this;
 155     }
 156
 157 #endif
 158
 159     template<class Y>
 160     explicit shared_ptr(weak_ptr<Y> const & r): pn(r.pn) // may throw
 161     {
 162         // it is now safe to copy r.px, as pn(r.pn) did not throw
 163         px = r.px;
 164     }
 165
 166     template<class Y>
 167     shared_ptr(shared_ptr<Y> const & r): px(r.px), pn(r.pn) // never throws
 168     {
 169     }
 170
 171     template<class Y>
 172     shared_ptr(shared_ptr<Y> const & r, detail::static_cast_tag): px(static_cast<element_type *>(r.px)), pn(r.pn)
 173     {
 174     }
 175
 176     template<class Y>
 177     shared_ptr(shared_ptr<Y> const & r, detail::const_cast_tag): px(const_cast<element_type *>(r.px)), pn(r.pn)
 178     {
 179     }
 180
 181     template<class Y>
 182     shared_ptr(shared_ptr<Y> const & r, detail::dynamic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)
 183     {
 184         if(px == 0) // need to allocate new counter -- the cast failed
 185         {
 186             pn = detail::shared_count();
 187         }
 188     }
 189
 190     template<class Y>
 191     shared_ptr(shared_ptr<Y> const & r, detail::polymorphic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)
 192     {
 193         if(px == 0)
 194         {
 195             boost::serialization::throw_exception(std::bad_cast());
 196         }
 197     }
 198
 199 #ifndef BOOST_NO_AUTO_PTR
 200
 201     template<class Y>
 202     explicit shared_ptr(std::auto_ptr<Y> & r): px(r.get()), pn()
 203     {
 204         Y * tmp = r.get();
 205         pn = detail::shared_count(r);
 206         detail::sp_enable_shared_from_this( pn, tmp, tmp );
 207     }
 208
 209 #endif
 210
 211 #if !defined(BOOST_MSVC) || (BOOST_MSVC > 1200)
 212
 213     template<class Y>
 214     shared_ptr & operator=(shared_ptr<Y> const & r) // never throws
 215     {
 216         px = r.px;
 217         pn = r.pn; // shared_count::op= doesn't throw
 218         return *this;
 219     }
 220
 221 #endif
 222
 223 #ifndef BOOST_NO_AUTO_PTR
 224
 225     template<class Y>
 226     shared_ptr & operator=(std::auto_ptr<Y> & r)
 227     {
 228         this_type(r).swap(*this);
 229         return *this;
 230     }
 231
 232 #endif
 233
 234     void reset() // never throws in 1.30+
 235     {
 236         this_type().swap(*this);
 237     }
 238
 239     template<class Y> void reset(Y * p) // Y must be complete
 240     {
 241         BOOST_ASSERT(p == 0 || p != px); // catch self-reset errors
 242         this_type(p).swap(*this);
 243     }
 244
 245     template<class Y, class D> void reset(Y * p, D d)
 246     {
 247         this_type(p, d).swap(*this);
 248     }
 249
 250     reference operator* () const // never throws
 251     {
 252         BOOST_ASSERT(px != 0);
 253         return *px;
 254     }
 255
 256     T * operator-> () const // never throws
 257     {
 258         BOOST_ASSERT(px != 0);
 259         return px;
 260     }
 261
 262     T * get() const // never throws
 263     {
 264         return px;
 265     }
 266
 267     // implicit conversion to "bool"
 268
 269 #if defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x530)
 270
 271     operator bool () const
 272     {
 273         return px != 0;
 274     }
 275
 276 #elif defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
 277     typedef T * (this_type::*unspecified_bool_type)() const;
 278
 279     operator unspecified_bool_type() const // never throws
 280     {
 281         return px == 0? 0: &this_type::get;
 282     }
 283
 284 #else
 285
 286     typedef T * this_type::*unspecified_bool_type;
 287
 288     operator unspecified_bool_type() const // never throws
 289     {
 290         return px == 0? 0: &this_type::px;
 291     }
 292
 293 #endif
 294
 295     // operator! is redundant, but some compilers need it
 296
 297     bool operator! () const // never throws
 298     {
 299         return px == 0;
 300     }
 301
 302     bool unique() const // never throws
 303     {
 304         return pn.unique();
 305     }
 306
 307     long use_count() const // never throws
 308     {
 309         return pn.use_count();
 310     }
 311
 312     void swap(shared_ptr<T> & other) // never throws
 313     {
 314         std::swap(px, other.px);
 315         pn.swap(other.pn);
 316     }
 317
 318     template<class Y> bool _internal_less(shared_ptr<Y> const & rhs) const
 319     {
 320         return pn < rhs.pn;
 321     }
 322
 323     void * _internal_get_deleter(std::type_info const & ti) const
 324     {
 325         return pn.get_deleter(ti);
 326     }
 327
 328 // Tasteless as this may seem, making all members public allows member templates
 329 // to work in the absence of member template friends. (Matthew Langston)
 330
 331 #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
 332
 333 private:
 334
 335     template<class Y> friend class shared_ptr;
 336     template<class Y> friend class weak_ptr;
 337
 338
 339 #endif
 340 public: // for serialization
 341     T * px;                     // contained pointer
 342     detail::shared_count pn;    // reference counter
 343
 344 };  // shared_ptr
 345
 346 template<class T, class U> inline bool operator==(shared_ptr<T> const & a, shared_ptr<U> const & b)
 347 {
 348     return a.get() == b.get();
 349 }
 350
 351 template<class T, class U> inline bool operator!=(shared_ptr<T> const & a, shared_ptr<U> const & b)
 352 {
 353     return a.get() != b.get();
 354 }
 355
 356 #if __GNUC__ == 2 && __GNUC_MINOR__ <= 96
 357
 358 // Resolve the ambiguity between our op!= and the one in rel_ops
 359
 360 template<class T> inline bool operator!=(shared_ptr<T> const & a, shared_ptr<T> const & b)
 361 {
 362     return a.get() != b.get();
 363 }
 364
 365 #endif
 366
 367 template<class T, class U> inline bool operator<(shared_ptr<T> const & a, shared_ptr<U> const & b)
 368 {
 369     return a._internal_less(b);
 370 }
 371
 372 template<class T> inline void swap(shared_ptr<T> & a, shared_ptr<T> & b)
 373 {
 374     a.swap(b);
 375 }
 376
 377 template<class T, class U> shared_ptr<T> static_pointer_cast(shared_ptr<U> const & r)
 378 {
 379     return shared_ptr<T>(r, detail::static_cast_tag());
 380 }
 381
 382 template<class T, class U> shared_ptr<T> const_pointer_cast(shared_ptr<U> const & r)
 383 {
 384     return shared_ptr<T>(r, detail::const_cast_tag());
 385 }
 386
 387 template<class T, class U> shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const & r)
 388 {
 389     return shared_ptr<T>(r, detail::dynamic_cast_tag());
 390 }
 391
 392 // shared_*_cast names are deprecated. Use *_pointer_cast instead.
 393
 394 template<class T, class U> shared_ptr<T> shared_static_cast(shared_ptr<U> const & r)
 395 {
 396     return shared_ptr<T>(r, detail::static_cast_tag());
 397 }
 398
 399 template<class T, class U> shared_ptr<T> shared_dynamic_cast(shared_ptr<U> const & r)
 400 {
 401     return shared_ptr<T>(r, detail::dynamic_cast_tag());
 402 }
 403
 404 template<class T, class U> shared_ptr<T> shared_polymorphic_cast(shared_ptr<U> const & r)
 405 {
 406     return shared_ptr<T>(r, detail::polymorphic_cast_tag());
 407 }
 408
 409 template<class T, class U> shared_ptr<T> shared_polymorphic_downcast(shared_ptr<U> const & r)
 410 {
 411     BOOST_ASSERT(dynamic_cast<T *>(r.get()) == r.get());
 412     return shared_static_cast<T>(r);
 413 }
 414
 415 // get_pointer() enables boost::mem_fn to recognize shared_ptr
 416
 417 template<class T> inline T * get_pointer(shared_ptr<T> const & p)
 418 {
 419     return p.get();
 420 }
 421
 422 // operator<<
 423
 424 #if defined(__GNUC__) &&  (__GNUC__ < 3)
 425
 426 template<class Y> std::ostream & operator<< (std::ostream & os, shared_ptr<Y> const & p)
 427 {
 428     os << p.get();
 429     return os;
 430 }
 431
 432 #else
 433
 434 # if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, <= 1200 && __SGI_STL_PORT)
 435 // MSVC6 has problems finding std::basic_ostream through the using declaration in namespace _STL
 436 using std::basic_ostream;
 437 template<class E, class T, class Y> basic_ostream<E, T> & operator<< (basic_ostream<E, T> & os, shared_ptr<Y> const & p)
 438 # else
 439 template<class E, class T, class Y> std::basic_ostream<E, T> & operator<< (std::basic_ostream<E, T> & os, shared_ptr<Y> const & p)
 440 # endif
 441 {
 442     os << p.get();
 443     return os;
 444 }
 445
 446 #endif
 447
 448 // get_deleter (experimental)
 449
 450 #if (defined(__GNUC__) &&  (__GNUC__ < 3)) || (defined(__EDG_VERSION__) && (__EDG_VERSION__ <= 238))
 451
 452 // g++ 2.9x doesn't allow static_cast<X const *>(void *)
 453 // apparently EDG 2.38 also doesn't accept it
 454
 455 template<class D, class T> D * get_deleter(shared_ptr<T> const & p)
 456 {
 457     void const * q = p._internal_get_deleter(typeid(D));
 458     return const_cast<D *>(static_cast<D const *>(q));
 459 }
 460
 461 #else
 462
 463 template<class D, class T> D * get_deleter(shared_ptr<T> const & p)
 464 {
 465     return static_cast<D *>(p._internal_get_deleter(typeid(D)));
 466 }
 467
 468 #endif
 469
 470 } // namespace boost
 471
 472 #ifdef BOOST_MSVC
 473 # pragma warning(pop)
 474 #endif
 475
 476 #endif  // #if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)
 477
 478 #endif  // #ifndef BOOST_SHARED_PTR_132_HPP_INCLUDED