shared_ptr.h
#ifndef BOOSTER_SMART_PTR_SHARED_PTR_HPP_INCLUDED
#define BOOSTER_SMART_PTR_SHARED_PTR_HPP_INCLUDED
//
// shared_ptr.hpp
//
// (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
// Copyright (c) 2001-2008 Peter Dimov
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/smart_ptr/shared_ptr.htm for documentation.
//
#include <booster/config.h> // for broken compiler workarounds
#include <memory>
#include <cassert>
#include <booster/backtrace.h>
#include <booster/checked_delete.h>
#include <booster/smart_ptr/shared_count.h>
#include <booster/smart_ptr/sp_convertible.h>
#include <algorithm> // for std::swap
#include <functional> // for std::less
#include <typeinfo> // for std::bad_cast
#include <iosfwd> // for std::basic_ostream
#ifdef BOOSTER_MSVC // moved here to work around VC++ compiler crash
# pragma warning(push)
# pragma warning(disable:4284) // odd return type for operator->
#endif
namespace booster
{
template<class T> class shared_ptr;
template<class T> class weak_ptr;
template<class T> class enable_shared_from_this;
template<class T> class enable_shared_from_this2;
namespace detail
{
struct static_cast_tag {};
struct const_cast_tag {};
struct dynamic_cast_tag {};
struct polymorphic_cast_tag {};
template<class T> struct shared_ptr_traits
{
typedef T & reference;
};
template<> struct shared_ptr_traits<void>
{
typedef void reference;
};
template<> struct shared_ptr_traits<void const>
{
typedef void reference;
};
template<> struct shared_ptr_traits<void volatile>
{
typedef void reference;
};
template<> struct shared_ptr_traits<void const volatile>
{
typedef void reference;
};
// enable_shared_from_this support
template< class X, class Y, class T > inline void sp_enable_shared_from_this( booster::shared_ptr<X> const * ppx, Y const * py, booster::enable_shared_from_this< T > const * pe )
{
if( pe != 0 )
{
pe->_internal_accept_owner( ppx, const_cast< Y* >( py ) );
}
}
template< class X, class Y, class T > inline void sp_enable_shared_from_this( booster::shared_ptr<X> * ppx, Y const * py, booster::enable_shared_from_this2< T > const * pe )
{
if( pe != 0 )
{
pe->_internal_accept_owner( ppx, const_cast< Y* >( py ) );
}
}
inline void sp_enable_shared_from_this( ... )
{
}
// rvalue auto_ptr support based on a technique by Dave Abrahams
template< class T, class R > struct sp_enable_if_auto_ptr
{
};
template< class T, class R > struct sp_enable_if_auto_ptr< std::auto_ptr< T >, R >
{
typedef R type;
};
} // namespace detail
//
// shared_ptr
//
// An enhanced relative of scoped_ptr with reference counted copy semantics.
// The object pointed to is deleted when the last shared_ptr pointing to it
// is destroyed or reset.
//
template<class T> class shared_ptr
{
private:
// Borland 5.5.1 specific workaround
typedef shared_ptr<T> this_type;
public:
typedef T element_type;
typedef T value_type;
typedef T * pointer;
typedef typename booster::detail::shared_ptr_traits<T>::reference reference;
shared_ptr(): px(0), pn() // never throws in 1.30+
{
}
template<class Y>
explicit shared_ptr( Y * p ): px( p ), pn( p ) // Y must be complete
{
booster::detail::sp_enable_shared_from_this( this, p, p );
}
//
// Requirements: D's copy constructor must not throw
//
// shared_ptr will release p by calling d(p)
//
template<class Y, class D> shared_ptr(Y * p, D d): px(p), pn(p, d)
{
booster::detail::sp_enable_shared_from_this( this, p, p );
}
// As above, but with allocator. A's copy constructor shall not throw.
template<class Y, class D, class A> shared_ptr( Y * p, D d, A a ): px( p ), pn( p, d, a )
{
booster::detail::sp_enable_shared_from_this( this, p, p );
}
// generated copy constructor, destructor are fine
template<class Y>
explicit shared_ptr(weak_ptr<Y> const & r): pn(r.pn) // may throw
{
// it is now safe to copy r.px, as pn(r.pn) did not throw
px = r.px;
}
template<class Y>
shared_ptr( weak_ptr<Y> const & r, booster::detail::sp_nothrow_tag ): px( 0 ), pn( r.pn, booster::detail::sp_nothrow_tag() ) // never throws
{
if( !pn.empty() )
{
px = r.px;
}
}
template<class Y>
shared_ptr( shared_ptr<Y> const & r, typename detail::sp_enable_if_convertible<Y,T>::type = detail::sp_empty() )
: px( r.px ), pn( r.pn ) // never throws
{
}
// aliasing
template< class Y >
shared_ptr( shared_ptr<Y> const & r, T * p ): px( p ), pn( r.pn ) // never throws
{
}
template<class Y>
shared_ptr(shared_ptr<Y> const & r, booster::detail::static_cast_tag): px(static_cast<element_type *>(r.px)), pn(r.pn)
{
}
template<class Y>
shared_ptr(shared_ptr<Y> const & r, booster::detail::const_cast_tag): px(const_cast<element_type *>(r.px)), pn(r.pn)
{
}
template<class Y>
shared_ptr(shared_ptr<Y> const & r, booster::detail::dynamic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)
{
if(px == 0) // need to allocate new counter -- the cast failed
{
pn = booster::detail::shared_count();
}
}
template<class Y>
shared_ptr(shared_ptr<Y> const & r, booster::detail::polymorphic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)
{
if(px == 0)
{
throw booster::bad_cast();
}
}
template<class Y>
explicit shared_ptr(std::auto_ptr<Y> & r): px(r.get()), pn()
{
Y * tmp = r.get();
pn = booster::detail::shared_count(r);
booster::detail::sp_enable_shared_from_this( this, tmp, tmp );
}
template<class Ap>
explicit shared_ptr( Ap r, typename booster::detail::sp_enable_if_auto_ptr<Ap, int>::type = 0 ): px( r.get() ), pn()
{
typename Ap::element_type * tmp = r.get();
pn = booster::detail::shared_count( r );
booster::detail::sp_enable_shared_from_this( this, tmp, tmp );
}
// assignment
shared_ptr & operator=( shared_ptr const & r ) // never throws
{
this_type(r).swap(*this);
return *this;
}
template<class Y>
shared_ptr & operator=(shared_ptr<Y> const & r) // never throws
{
this_type(r).swap(*this);
return *this;
}
template<class Y>
shared_ptr & operator=( std::auto_ptr<Y> & r )
{
this_type(r).swap(*this);
return *this;
}
template<class Ap>
typename booster::detail::sp_enable_if_auto_ptr< Ap, shared_ptr & >::type operator=( Ap r )
{
this_type( r ).swap( *this );
return *this;
}
// Move support
void reset() // never throws in 1.30+
{
this_type().swap(*this);
}
template<class Y> void reset(Y * p) // Y must be complete
{
assert(p == 0 || p != px); // catch self-reset errors
this_type(p).swap(*this);
}
template<class Y, class D> void reset( Y * p, D d )
{
this_type( p, d ).swap( *this );
}
template<class Y, class D, class A> void reset( Y * p, D d, A a )
{
this_type( p, d, a ).swap( *this );
}
template<class Y> void reset( shared_ptr<Y> const & r, T * p )
{
this_type( r, p ).swap( *this );
}
reference operator* () const // never throws
{
assert(px != 0);
return *px;
}
T * operator-> () const // never throws
{
assert(px != 0);
return px;
}
T * get() const // never throws
{
return px;
}
// implicit conversion to "bool"
#include <booster/smart_ptr/operator_bool.h>
bool unique() const // never throws
{
return pn.unique();
}
long use_count() const // never throws
{
return pn.use_count();
}
void swap(shared_ptr<T> & other) // never throws
{
std::swap(px, other.px);
pn.swap(other.pn);
}
template<class Y> bool _internal_less(shared_ptr<Y> const & rhs) const
{
return pn < rhs.pn;
}
void * _internal_get_deleter( detail::sp_typeinfo const & ti ) const
{
return pn.get_deleter( ti );
}
bool _internal_equiv( shared_ptr const & r ) const
{
return px == r.px && pn == r.pn;
}
// Tasteless as this may seem, making all members public allows member templates
// to work in the absence of member template friends. (Matthew Langston)
private:
template<class Y> friend class shared_ptr;
template<class Y> friend class weak_ptr;
T * px; // contained pointer
booster::detail::shared_count pn; // reference counter
}; // shared_ptr
template<class T, class U> inline bool operator==(shared_ptr<T> const & a, shared_ptr<U> const & b)
{
return a.get() == b.get();
}
template<class T, class U> inline bool operator!=(shared_ptr<T> const & a, shared_ptr<U> const & b)
{
return a.get() != b.get();
}
template<class T, class U> inline bool operator<(shared_ptr<T> const & a, shared_ptr<U> const & b)
{
return a._internal_less(b);
}
template<class T> inline void swap(shared_ptr<T> & a, shared_ptr<T> & b)
{
a.swap(b);
}
template<class T, class U> shared_ptr<T> static_pointer_cast(shared_ptr<U> const & r)
{
return shared_ptr<T>(r, booster::detail::static_cast_tag());
}
template<class T, class U> shared_ptr<T> const_pointer_cast(shared_ptr<U> const & r)
{
return shared_ptr<T>(r, booster::detail::const_cast_tag());
}
template<class T, class U> shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const & r)
{
return shared_ptr<T>(r, booster::detail::dynamic_cast_tag());
}
// shared_*_cast names are deprecated. Use *_pointer_cast instead.
template<class T, class U> shared_ptr<T> shared_static_cast(shared_ptr<U> const & r)
{
return shared_ptr<T>(r, booster::detail::static_cast_tag());
}
template<class T, class U> shared_ptr<T> shared_dynamic_cast(shared_ptr<U> const & r)
{
return shared_ptr<T>(r, booster::detail::dynamic_cast_tag());
}
template<class T, class U> shared_ptr<T> shared_polymorphic_cast(shared_ptr<U> const & r)
{
return shared_ptr<T>(r, booster::detail::polymorphic_cast_tag());
}
template<class T, class U> shared_ptr<T> shared_polymorphic_downcast(shared_ptr<U> const & r)
{
assert(dynamic_cast<T *>(r.get()) == r.get());
return shared_static_cast<T>(r);
}
// get_pointer() enables boost::mem_fn to recognize shared_ptr
template<class T> inline T * get_pointer(shared_ptr<T> const & p)
{
return p.get();
}
// operator<<
template<class Y> std::ostream & operator<< (std::ostream & os, shared_ptr<Y> const & p)
{
os << p.get();
return os;
}
// get_deleter
template<class D, class T> D * get_deleter(shared_ptr<T> const & p)
{
return static_cast<D *>(p._internal_get_deleter(BOOSTER_SP_TYPEID(D)));
}
} // namespace boost
#ifdef BOOSTER_MSVC
# pragma warning(pop)
#endif
#endif // #ifndef BOOST_SMART_PTR_SHARED_PTR_HPP_INCLUDED
booster::detail::dynamic_cast_tag
Definition: shared_ptr.h:50
booster::detail::shared_count
Definition: shared_count.h:37
booster::detail::polymorphic_cast_tag
Definition: shared_ptr.h:51
booster::shared_ptr
Definition: log.h:25
booster::enable_shared_from_this2
Definition: shared_ptr.h:43
booster::detail::sp_enable_if_auto_ptr
Definition: shared_ptr.h:103
booster::detail::const_cast_tag
Definition: shared_ptr.h:49
booster::bad_cast
Same as std::bad_cast but records stack trace.
Definition: backtrace.h:151
booster::enable_shared_from_this
This class is borrowed from boost.
Definition: enable_shared_from_this.h:30
booster::detail::sp_nothrow_tag
Definition: shared_count.h:33
booster::detail::shared_ptr_traits
Definition: shared_ptr.h:53
booster::detail::static_cast_tag
Definition: shared_ptr.h:48