465 lines
11 KiB
C++
465 lines
11 KiB
C++
#ifndef BOOST_SHARED_PTR_HPP_INCLUDED
|
|
#define BOOST_SHARED_PTR_HPP_INCLUDED
|
|
|
|
//
|
|
// shared_ptr.hpp
|
|
//
|
|
// (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
|
|
// Copyright (c) 2001, 2002, 2003 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 "assert.hpp"
|
|
#include "checked_delete.hpp"
|
|
#include "throw_exception.hpp"
|
|
#include "shared_count.hpp"
|
|
#include "workaround.hpp"
|
|
|
|
#include <memory> // for std::auto_ptr
|
|
#include <algorithm> // for std::swap
|
|
#include <functional> // for std::less
|
|
#include <typeinfo> // for std::bad_cast
|
|
#include <iosfwd> // for std::basic_ostream
|
|
|
|
#ifdef BOOST_MSVC // moved here to work around VC++ compiler crash
|
|
# pragma warning(push)
|
|
# pragma warning(disable:4284) // odd return type for operator->
|
|
#endif
|
|
|
|
namespace boost
|
|
{
|
|
|
|
template<class T> class weak_ptr;
|
|
template<class T> class enable_shared_from_this;
|
|
|
|
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;
|
|
};
|
|
|
|
#if !defined(BOOST_NO_CV_VOID_SPECIALIZATIONS)
|
|
|
|
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 T, class Y> void sp_enable_shared_from_this( shared_count const & pn, boost::enable_shared_from_this<T> const * pe, Y const * px )
|
|
{
|
|
if(pe != 0) pe->_internal_weak_this._internal_assign(const_cast<Y*>(px), pn);
|
|
}
|
|
|
|
inline void sp_enable_shared_from_this( shared_count const & /*pn*/, ... )
|
|
{
|
|
}
|
|
|
|
} // 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 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, checked_deleter<Y>()) // Y must be complete
|
|
{
|
|
detail::sp_enable_shared_from_this( pn, 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)
|
|
{
|
|
detail::sp_enable_shared_from_this( pn, p, p );
|
|
}
|
|
|
|
// generated copy constructor, assignment, destructor are fine...
|
|
|
|
// except that Borland C++ has a bug, and g++ with -Wsynth warns
|
|
#if defined(__BORLANDC__) || defined(__GNUC__)
|
|
|
|
shared_ptr & operator=(shared_ptr const & r) // never throws
|
|
{
|
|
px = r.px;
|
|
pn = r.pn; // shared_count::op= doesn't throw
|
|
return *this;
|
|
}
|
|
|
|
#endif
|
|
|
|
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(shared_ptr<Y> const & r): px(r.px), pn(r.pn) // never throws
|
|
{
|
|
}
|
|
|
|
template<class Y>
|
|
shared_ptr(shared_ptr<Y> const & r, detail::static_cast_tag): px(static_cast<element_type *>(r.px)), pn(r.pn)
|
|
{
|
|
}
|
|
|
|
template<class Y>
|
|
shared_ptr(shared_ptr<Y> const & r, detail::const_cast_tag): px(const_cast<element_type *>(r.px)), pn(r.pn)
|
|
{
|
|
}
|
|
|
|
template<class Y>
|
|
shared_ptr(shared_ptr<Y> const & r, 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 = detail::shared_count();
|
|
}
|
|
}
|
|
|
|
template<class Y>
|
|
shared_ptr(shared_ptr<Y> const & r, detail::polymorphic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)
|
|
{
|
|
if(px == 0)
|
|
{
|
|
boost::throw_exception(std::bad_cast());
|
|
}
|
|
}
|
|
|
|
#ifndef BOOST_NO_AUTO_PTR
|
|
|
|
template<class Y>
|
|
explicit shared_ptr(std::auto_ptr<Y> & r): px(r.get()), pn()
|
|
{
|
|
Y * tmp = r.get();
|
|
pn = detail::shared_count(r);
|
|
detail::sp_enable_shared_from_this( pn, tmp, tmp );
|
|
}
|
|
|
|
#endif
|
|
|
|
#if !defined(BOOST_MSVC) || (BOOST_MSVC > 1200)
|
|
|
|
template<class Y>
|
|
shared_ptr & operator=(shared_ptr<Y> const & r) // never throws
|
|
{
|
|
px = r.px;
|
|
pn = r.pn; // shared_count::op= doesn't throw
|
|
return *this;
|
|
}
|
|
|
|
#endif
|
|
|
|
#ifndef BOOST_NO_AUTO_PTR
|
|
|
|
template<class Y>
|
|
shared_ptr & operator=(std::auto_ptr<Y> & r)
|
|
{
|
|
this_type(r).swap(*this);
|
|
return *this;
|
|
}
|
|
|
|
#endif
|
|
|
|
void reset() // never throws in 1.30+
|
|
{
|
|
this_type().swap(*this);
|
|
}
|
|
|
|
template<class Y> void reset(Y * p) // Y must be complete
|
|
{
|
|
BOOST_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);
|
|
}
|
|
|
|
reference operator* () const // never throws
|
|
{
|
|
BOOST_ASSERT(px != 0);
|
|
return *px;
|
|
}
|
|
|
|
T * operator-> () const // never throws
|
|
{
|
|
BOOST_ASSERT(px != 0);
|
|
return px;
|
|
}
|
|
|
|
T * get() const // never throws
|
|
{
|
|
return px;
|
|
}
|
|
|
|
// implicit conversion to "bool"
|
|
|
|
#if defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x530)
|
|
|
|
operator bool () const
|
|
{
|
|
return px != 0;
|
|
}
|
|
|
|
#elif defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
|
|
typedef T * (this_type::*unspecified_bool_type)() const;
|
|
|
|
operator unspecified_bool_type() const // never throws
|
|
{
|
|
return px == 0? 0: &this_type::get;
|
|
}
|
|
|
|
#else
|
|
|
|
typedef T * this_type::*unspecified_bool_type;
|
|
|
|
operator unspecified_bool_type() const // never throws
|
|
{
|
|
return px == 0? 0: &this_type::px;
|
|
}
|
|
|
|
#endif
|
|
|
|
// operator! is redundant, but some compilers need it
|
|
|
|
bool operator! () const // never throws
|
|
{
|
|
return px == 0;
|
|
}
|
|
|
|
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(std::type_info const & ti) const
|
|
{
|
|
return pn.get_deleter(ti);
|
|
}
|
|
|
|
// Tasteless as this may seem, making all members public allows member templates
|
|
// to work in the absence of member template friends. (Matthew Langston)
|
|
|
|
#ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
|
|
|
|
private:
|
|
|
|
template<class Y> friend class shared_ptr;
|
|
template<class Y> friend class weak_ptr;
|
|
|
|
|
|
#endif
|
|
|
|
T * px; // contained pointer
|
|
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();
|
|
}
|
|
|
|
#if __GNUC__ == 2 && __GNUC_MINOR__ <= 96
|
|
|
|
// Resolve the ambiguity between our op!= and the one in rel_ops
|
|
|
|
template<class T> inline bool operator!=(shared_ptr<T> const & a, shared_ptr<T> const & b)
|
|
{
|
|
return a.get() != b.get();
|
|
}
|
|
|
|
#endif
|
|
|
|
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, 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, 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, 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, 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, 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, detail::polymorphic_cast_tag());
|
|
}
|
|
|
|
template<class T, class U> shared_ptr<T> shared_polymorphic_downcast(shared_ptr<U> const & r)
|
|
{
|
|
BOOST_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<<
|
|
|
|
#if defined(__GNUC__) && (__GNUC__ < 3)
|
|
|
|
template<class Y> std::ostream & operator<< (std::ostream & os, shared_ptr<Y> const & p)
|
|
{
|
|
os << p.get();
|
|
return os;
|
|
}
|
|
|
|
#else
|
|
|
|
# if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, <= 1200 && __SGI_STL_PORT)
|
|
// MSVC6 has problems finding std::basic_ostream through the using declaration in namespace _STL
|
|
using std::basic_ostream;
|
|
template<class E, class T, class Y> basic_ostream<E, T> & operator<< (basic_ostream<E, T> & os, shared_ptr<Y> const & p)
|
|
# else
|
|
template<class E, class T, class Y> std::basic_ostream<E, T> & operator<< (std::basic_ostream<E, T> & os, shared_ptr<Y> const & p)
|
|
# endif
|
|
{
|
|
os << p.get();
|
|
return os;
|
|
}
|
|
|
|
#endif
|
|
|
|
// get_deleter (experimental)
|
|
|
|
#if (defined(__GNUC__) && (__GNUC__ < 3)) || (defined(__EDG_VERSION__) && (__EDG_VERSION__ <= 238))
|
|
|
|
// g++ 2.9x doesn't allow static_cast<X const *>(void *)
|
|
// apparently EDG 2.38 also doesn't accept it
|
|
|
|
template<class D, class T> D * get_deleter(shared_ptr<T> const & p)
|
|
{
|
|
void const * q = p._internal_get_deleter(typeid(D));
|
|
return const_cast<D *>(static_cast<D const *>(q));
|
|
}
|
|
|
|
#else
|
|
|
|
template<class D, class T> D * get_deleter(shared_ptr<T> const & p)
|
|
{
|
|
return static_cast<D *>(p._internal_get_deleter(typeid(D)));
|
|
}
|
|
|
|
#endif
|
|
|
|
} // namespace boost
|
|
|
|
#ifdef BOOST_MSVC
|
|
# pragma warning(pop)
|
|
#endif
|
|
|
|
#endif // #if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)
|
|
|
|
#endif // #ifndef BOOST_SHARED_PTR_HPP_INCLUDED
|