1 #ifndef BOOST_SHARED_PTR_HPP_INCLUDED
2 #define BOOST_SHARED_PTR_HPP_INCLUDED
7 // (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
8 // Copyright (c) 2001-2008 Peter Dimov
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)
14 // See http://www.boost.org/libs/smart_ptr/shared_ptr.htm for documentation.
17 #include <boost/config.hpp> // for broken compiler workarounds
19 #if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)
20 #include <boost/detail/shared_ptr_nmt.hpp>
23 // In order to avoid circular dependencies with Boost.TR1
24 // we make sure that our include of <memory> doesn't try to
25 // pull in the TR1 headers: that's why we use this header
26 // rather than including <memory> directly:
27 #include <boost/config/no_tr1/memory.hpp> // std::auto_ptr
29 #include <boost/assert.hpp>
30 #include <boost/checked_delete.hpp>
31 #include <boost/throw_exception.hpp>
32 #include <boost/detail/shared_count.hpp>
33 #include <boost/detail/workaround.hpp>
34 #include <boost/detail/sp_convertible.hpp>
36 #if !defined(BOOST_SP_NO_ATOMIC_ACCESS)
37 #include <boost/detail/spinlock_pool.hpp>
38 #include <boost/memory_order.hpp>
41 #include <algorithm> // for std::swap
42 #include <functional> // for std::less
43 #include <typeinfo> // for std::bad_cast
45 #if !defined(BOOST_NO_IOSTREAM)
46 #if !defined(BOOST_NO_IOSFWD)
47 #include <iosfwd> // for std::basic_ostream
53 #ifdef BOOST_MSVC // moved here to work around VC++ compiler crash
54 # pragma warning(push)
55 # pragma warning(disable:4284) // odd return type for operator->
61 template<class T> class weak_ptr;
62 template<class T> class enable_shared_from_this;
67 struct static_cast_tag {};
68 struct const_cast_tag {};
69 struct dynamic_cast_tag {};
70 struct polymorphic_cast_tag {};
72 template<class T> struct shared_ptr_traits
74 typedef T & reference;
77 template<> struct shared_ptr_traits<void>
79 typedef void reference;
82 #if !defined(BOOST_NO_CV_VOID_SPECIALIZATIONS)
84 template<> struct shared_ptr_traits<void const>
86 typedef void reference;
89 template<> struct shared_ptr_traits<void volatile>
91 typedef void reference;
94 template<> struct shared_ptr_traits<void const volatile>
96 typedef void reference;
101 // enable_shared_from_this support
103 template<class T, class Y> void sp_enable_shared_from_this( shared_count const & pn, boost::enable_shared_from_this<T> const * pe, Y const * px )
105 if(pe != 0) pe->_internal_weak_this._internal_assign(const_cast<Y*>(px), pn);
110 // Avoid C4793, ... causes native code generation
112 struct sp_any_pointer
114 template<class T> sp_any_pointer( T* ) {}
117 inline void sp_enable_shared_from_this( shared_count const & /*pn*/, sp_any_pointer, sp_any_pointer )
124 // Turn off: the last argument of the varargs function "sp_enable_shared_from_this" is unnamed
125 # pragma set woff 3506
128 inline void sp_enable_shared_from_this( shared_count const & /*pn*/, ... )
133 # pragma reset woff 3506
138 #if !defined( BOOST_NO_SFINAE ) && !defined( BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION ) && !defined( BOOST_NO_AUTO_PTR )
140 // rvalue auto_ptr support based on a technique by Dave Abrahams
142 template< class T, class R > struct sp_enable_if_auto_ptr
146 template< class T, class R > struct sp_enable_if_auto_ptr< std::auto_ptr< T >, R >
153 } // namespace detail
159 // An enhanced relative of scoped_ptr with reference counted copy semantics.
160 // The object pointed to is deleted when the last shared_ptr pointing to it
161 // is destroyed or reset.
164 template<class T> class shared_ptr
168 // Borland 5.5.1 specific workaround
169 typedef shared_ptr<T> this_type;
173 typedef T element_type;
174 typedef T value_type;
176 typedef typename boost::detail::shared_ptr_traits<T>::reference reference;
178 shared_ptr(): px(0), pn() // never throws in 1.30+
183 explicit shared_ptr( Y * p ): px( p ), pn( p ) // Y must be complete
185 boost::detail::sp_enable_shared_from_this( pn, p, p );
189 // Requirements: D's copy constructor must not throw
191 // shared_ptr will release p by calling d(p)
194 template<class Y, class D> shared_ptr(Y * p, D d): px(p), pn(p, d)
196 boost::detail::sp_enable_shared_from_this( pn, p, p );
199 // As above, but with allocator. A's copy constructor shall not throw.
201 template<class Y, class D, class A> shared_ptr( Y * p, D d, A a ): px( p ), pn( p, d, a )
203 boost::detail::sp_enable_shared_from_this( pn, p, p );
206 // generated copy constructor, assignment, destructor are fine...
208 // except that Borland C++ has a bug, and g++ with -Wsynth warns
209 #if defined(__BORLANDC__) || defined(__GNUC__)
211 shared_ptr & operator=(shared_ptr const & r) // never throws
214 pn = r.pn; // shared_count::op= doesn't throw
221 explicit shared_ptr(weak_ptr<Y> const & r): pn(r.pn) // may throw
223 // it is now safe to copy r.px, as pn(r.pn) did not throw
228 shared_ptr( weak_ptr<Y> const & r, boost::detail::sp_nothrow_tag ): px( 0 ), pn( r.pn, boost::detail::sp_nothrow_tag() ) // never throws
237 #if !defined( BOOST_SP_NO_SP_CONVERTIBLE )
239 shared_ptr( shared_ptr<Y> const & r, typename detail::sp_enable_if_convertible<Y,T>::type = detail::sp_empty() )
243 shared_ptr( shared_ptr<Y> const & r )
246 : px( r.px ), pn( r.pn ) // never throws
252 shared_ptr( shared_ptr<Y> const & r, T * p ): px( p ), pn( r.pn ) // never throws
257 shared_ptr(shared_ptr<Y> const & r, boost::detail::static_cast_tag): px(static_cast<element_type *>(r.px)), pn(r.pn)
262 shared_ptr(shared_ptr<Y> const & r, boost::detail::const_cast_tag): px(const_cast<element_type *>(r.px)), pn(r.pn)
267 shared_ptr(shared_ptr<Y> const & r, boost::detail::dynamic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)
269 if(px == 0) // need to allocate new counter -- the cast failed
271 pn = boost::detail::shared_count();
276 shared_ptr(shared_ptr<Y> const & r, boost::detail::polymorphic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)
280 boost::throw_exception(std::bad_cast());
284 #ifndef BOOST_NO_AUTO_PTR
287 explicit shared_ptr(std::auto_ptr<Y> & r): px(r.get()), pn()
290 pn = boost::detail::shared_count(r);
291 boost::detail::sp_enable_shared_from_this( pn, tmp, tmp );
294 #if !defined( BOOST_NO_SFINAE ) && !defined( BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION )
297 shared_ptr( Ap r, typename boost::detail::sp_enable_if_auto_ptr<Ap, int>::type = 0 ): px( r.get() ), pn()
299 typename Ap::element_type * tmp = r.get();
300 pn = boost::detail::shared_count( r );
301 boost::detail::sp_enable_shared_from_this( pn, tmp, tmp );
305 #endif // BOOST_NO_SFINAE, BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
307 #endif // BOOST_NO_AUTO_PTR
309 #if !defined(BOOST_MSVC) || (BOOST_MSVC >= 1300)
312 shared_ptr & operator=(shared_ptr<Y> const & r) // never throws
315 pn = r.pn; // shared_count::op= doesn't throw
321 #ifndef BOOST_NO_AUTO_PTR
324 shared_ptr & operator=( std::auto_ptr<Y> & r )
326 this_type(r).swap(*this);
330 #if !defined( BOOST_NO_SFINAE ) && !defined( BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION )
333 typename boost::detail::sp_enable_if_auto_ptr< Ap, shared_ptr & >::type operator=( Ap r )
335 this_type( r ).swap( *this );
340 #endif // BOOST_NO_SFINAE, BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
342 #endif // BOOST_NO_AUTO_PTR
346 #if defined( BOOST_HAS_RVALUE_REFS )
348 shared_ptr( shared_ptr && r ): px( r.px ), pn() // never throws
355 #if !defined( BOOST_SP_NO_SP_CONVERTIBLE )
357 shared_ptr( shared_ptr<Y> && r, typename detail::sp_enable_if_convertible<Y,T>::type = detail::sp_empty() )
361 shared_ptr( shared_ptr<Y> && r )
364 : px( r.px ), pn() // never throws
370 shared_ptr & operator=( shared_ptr && r ) // never throws
372 this_type( static_cast< shared_ptr && >( r ) ).swap( *this );
377 shared_ptr & operator=( shared_ptr<Y> && r ) // never throws
379 this_type( static_cast< shared_ptr<Y> && >( r ) ).swap( *this );
385 void reset() // never throws in 1.30+
387 this_type().swap(*this);
390 template<class Y> void reset(Y * p) // Y must be complete
392 BOOST_ASSERT(p == 0 || p != px); // catch self-reset errors
393 this_type(p).swap(*this);
396 template<class Y, class D> void reset( Y * p, D d )
398 this_type( p, d ).swap( *this );
401 template<class Y, class D, class A> void reset( Y * p, D d, A a )
403 this_type( p, d, a ).swap( *this );
406 template<class Y> void reset( shared_ptr<Y> const & r, T * p )
408 this_type( r, p ).swap( *this );
411 reference operator* () const // never throws
413 BOOST_ASSERT(px != 0);
417 T * operator-> () const // never throws
419 BOOST_ASSERT(px != 0);
423 T * get() const // never throws
428 // implicit conversion to "bool"
430 #if ( defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, < 0x570) ) || defined(__CINT__)
432 operator bool () const
437 #elif defined( _MANAGED )
439 static void unspecified_bool( this_type*** )
443 typedef void (*unspecified_bool_type)( this_type*** );
445 operator unspecified_bool_type() const // never throws
447 return px == 0? 0: unspecified_bool;
451 ( defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, < 0x3200) ) || \
452 ( defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ < 304) ) || \
453 ( defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x590) )
455 typedef T * (this_type::*unspecified_bool_type)() const;
457 operator unspecified_bool_type() const // never throws
459 return px == 0? 0: &this_type::get;
464 typedef T * this_type::*unspecified_bool_type;
466 operator unspecified_bool_type() const // never throws
468 return px == 0? 0: &this_type::px;
473 // operator! is redundant, but some compilers need it
475 bool operator! () const // never throws
480 bool unique() const // never throws
485 long use_count() const // never throws
487 return pn.use_count();
490 void swap(shared_ptr<T> & other) // never throws
492 std::swap(px, other.px);
496 template<class Y> bool _internal_less(shared_ptr<Y> const & rhs) const
501 void * _internal_get_deleter( detail::sp_typeinfo const & ti ) const
503 return pn.get_deleter( ti );
506 bool _internal_equiv( shared_ptr const & r ) const
508 return px == r.px && pn == r.pn;
511 // Tasteless as this may seem, making all members public allows member templates
512 // to work in the absence of member template friends. (Matthew Langston)
514 #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
518 template<class Y> friend class shared_ptr;
519 template<class Y> friend class weak_ptr;
524 T * px; // contained pointer
525 boost::detail::shared_count pn; // reference counter
529 template<class T, class U> inline bool operator==(shared_ptr<T> const & a, shared_ptr<U> const & b)
531 return a.get() == b.get();
534 template<class T, class U> inline bool operator!=(shared_ptr<T> const & a, shared_ptr<U> const & b)
536 return a.get() != b.get();
539 #if __GNUC__ == 2 && __GNUC_MINOR__ <= 96
541 // Resolve the ambiguity between our op!= and the one in rel_ops
543 template<class T> inline bool operator!=(shared_ptr<T> const & a, shared_ptr<T> const & b)
545 return a.get() != b.get();
550 template<class T, class U> inline bool operator<(shared_ptr<T> const & a, shared_ptr<U> const & b)
552 return a._internal_less(b);
555 template<class T> inline void swap(shared_ptr<T> & a, shared_ptr<T> & b)
560 template<class T, class U> shared_ptr<T> static_pointer_cast(shared_ptr<U> const & r)
562 return shared_ptr<T>(r, boost::detail::static_cast_tag());
565 template<class T, class U> shared_ptr<T> const_pointer_cast(shared_ptr<U> const & r)
567 return shared_ptr<T>(r, boost::detail::const_cast_tag());
570 template<class T, class U> shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const & r)
572 return shared_ptr<T>(r, boost::detail::dynamic_cast_tag());
575 // shared_*_cast names are deprecated. Use *_pointer_cast instead.
577 template<class T, class U> shared_ptr<T> shared_static_cast(shared_ptr<U> const & r)
579 return shared_ptr<T>(r, boost::detail::static_cast_tag());
582 template<class T, class U> shared_ptr<T> shared_dynamic_cast(shared_ptr<U> const & r)
584 return shared_ptr<T>(r, boost::detail::dynamic_cast_tag());
587 template<class T, class U> shared_ptr<T> shared_polymorphic_cast(shared_ptr<U> const & r)
589 return shared_ptr<T>(r, boost::detail::polymorphic_cast_tag());
592 template<class T, class U> shared_ptr<T> shared_polymorphic_downcast(shared_ptr<U> const & r)
594 BOOST_ASSERT(dynamic_cast<T *>(r.get()) == r.get());
595 return shared_static_cast<T>(r);
598 // get_pointer() enables boost::mem_fn to recognize shared_ptr
600 template<class T> inline T * get_pointer(shared_ptr<T> const & p)
607 #if !defined(BOOST_NO_IOSTREAM)
609 #if defined(BOOST_NO_TEMPLATED_IOSTREAMS) || ( defined(__GNUC__) && (__GNUC__ < 3) )
611 template<class Y> std::ostream & operator<< (std::ostream & os, shared_ptr<Y> const & p)
619 // in STLport's no-iostreams mode no iostream symbols can be used
620 #ifndef _STLP_NO_IOSTREAMS
622 # if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, < 1300 && __SGI_STL_PORT)
623 // MSVC6 has problems finding std::basic_ostream through the using declaration in namespace _STL
624 using std::basic_ostream;
625 template<class E, class T, class Y> basic_ostream<E, T> & operator<< (basic_ostream<E, T> & os, shared_ptr<Y> const & p)
627 template<class E, class T, class Y> std::basic_ostream<E, T> & operator<< (std::basic_ostream<E, T> & os, shared_ptr<Y> const & p)
634 #endif // _STLP_NO_IOSTREAMS
636 #endif // __GNUC__ < 3
638 #endif // !defined(BOOST_NO_IOSTREAM)
642 #if ( defined(__GNUC__) && BOOST_WORKAROUND(__GNUC__, < 3) ) || \
643 ( defined(__EDG_VERSION__) && BOOST_WORKAROUND(__EDG_VERSION__, <= 238) ) || \
644 ( defined(__HP_aCC) && BOOST_WORKAROUND(__HP_aCC, <= 33500) )
646 // g++ 2.9x doesn't allow static_cast<X const *>(void *)
647 // apparently EDG 2.38 and HP aCC A.03.35 also don't accept it
649 template<class D, class T> D * get_deleter(shared_ptr<T> const & p)
651 void const * q = p._internal_get_deleter(BOOST_SP_TYPEID(D));
652 return const_cast<D *>(static_cast<D const *>(q));
657 template<class D, class T> D * get_deleter(shared_ptr<T> const & p)
659 return static_cast<D *>(p._internal_get_deleter(BOOST_SP_TYPEID(D)));
666 #if !defined(BOOST_SP_NO_ATOMIC_ACCESS)
668 template<class T> inline bool atomic_is_lock_free( shared_ptr<T> const * /*p*/ )
673 template<class T> shared_ptr<T> atomic_load( shared_ptr<T> const * p )
675 boost::detail::spinlock_pool<2>::scoped_lock lock( p );
679 template<class T> inline shared_ptr<T> atomic_load_explicit( shared_ptr<T> const * p, memory_order /*mo*/ )
681 return atomic_load( p );
684 template<class T> void atomic_store( shared_ptr<T> * p, shared_ptr<T> r )
686 boost::detail::spinlock_pool<2>::scoped_lock lock( p );
690 template<class T> inline void atomic_store_explicit( shared_ptr<T> * p, shared_ptr<T> r, memory_order /*mo*/ )
692 atomic_store( p, r ); // std::move( r )
695 template<class T> shared_ptr<T> atomic_exchange( shared_ptr<T> * p, shared_ptr<T> r )
697 boost::detail::spinlock & sp = boost::detail::spinlock_pool<2>::spinlock_for( p );
703 return r; // return std::move( r )
706 template<class T> shared_ptr<T> atomic_exchange_explicit( shared_ptr<T> * p, shared_ptr<T> r, memory_order /*mo*/ )
708 return atomic_exchange( p, r ); // std::move( r )
711 template<class T> bool atomic_compare_exchange( shared_ptr<T> * p, shared_ptr<T> * v, shared_ptr<T> w )
713 boost::detail::spinlock & sp = boost::detail::spinlock_pool<2>::spinlock_for( p );
717 if( p->_internal_equiv( *v ) )
727 shared_ptr<T> tmp( *p );
736 template<class T> inline bool atomic_compare_exchange_explicit( shared_ptr<T> * p, shared_ptr<T> * v, shared_ptr<T> w, memory_order /*success*/, memory_order /*failure*/ )
738 return atomic_compare_exchange( p, v, w ); // std::move( w )
746 # pragma warning(pop)
749 #endif // #if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)
751 #endif // #ifndef BOOST_SHARED_PTR_HPP_INCLUDED