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* Shared (garbage collecting) pointers. Copied from Boost.
This commit is contained in:
Eelco Dolstra
parent
0b70231b9d
commit
6ba26f27c3
12 changed files with 1268 additions and 17 deletions
555
src/boost/detail/shared_count.hpp
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555
src/boost/detail/shared_count.hpp
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#ifndef BOOST_DETAIL_SHARED_COUNT_HPP_INCLUDED
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#define BOOST_DETAIL_SHARED_COUNT_HPP_INCLUDED
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// MS compatible compilers support #pragma once
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#if defined(_MSC_VER) && (_MSC_VER >= 1020)
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# pragma once
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#endif
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//
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// detail/shared_count.hpp
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//
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// Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
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//
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// Permission to copy, use, modify, sell and distribute this software
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// is granted provided this copyright notice appears in all copies.
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// This software is provided "as is" without express or implied
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// warranty, and with no claim as to its suitability for any purpose.
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//
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//#include <boost/config.hpp>
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#if defined(BOOST_SP_USE_STD_ALLOCATOR) && defined(BOOST_SP_USE_QUICK_ALLOCATOR)
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# error BOOST_SP_USE_STD_ALLOCATOR and BOOST_SP_USE_QUICK_ALLOCATOR are incompatible.
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#endif
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#include <boost/checked_delete.hpp>
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#include <boost/throw_exception.hpp>
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//#include <boost/detail/lightweight_mutex.hpp>
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#if defined(BOOST_SP_USE_QUICK_ALLOCATOR)
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#include <boost/detail/quick_allocator.hpp>
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#endif
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#include <memory> // std::auto_ptr, std::allocator
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#include <functional> // std::less
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#include <exception> // std::exception
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#include <new> // std::bad_alloc
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#include <typeinfo> // std::type_info in get_deleter
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#include <cstddef> // std::size_t
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#ifdef __BORLANDC__
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# pragma warn -8026 // Functions with excep. spec. are not expanded inline
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# pragma warn -8027 // Functions containing try are not expanded inline
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#endif
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namespace boost
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{
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// Debug hooks
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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void sp_scalar_constructor_hook(void * px, std::size_t size, void * pn);
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void sp_array_constructor_hook(void * px);
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void sp_scalar_destructor_hook(void * px, std::size_t size, void * pn);
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void sp_array_destructor_hook(void * px);
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#endif
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// The standard library that comes with Borland C++ 5.5.1
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// defines std::exception and its members as having C calling
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// convention (-pc). When the definition of bad_weak_ptr
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// is compiled with -ps, the compiler issues an error.
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// Hence, the temporary #pragma option -pc below. The version
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// check is deliberately conservative.
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#if defined(__BORLANDC__) && __BORLANDC__ == 0x551
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# pragma option push -pc
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#endif
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class bad_weak_ptr: public std::exception
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{
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public:
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virtual char const * what() const throw()
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{
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return "boost::bad_weak_ptr";
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}
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};
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#if defined(__BORLANDC__) && __BORLANDC__ == 0x551
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# pragma option pop
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#endif
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namespace detail
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{
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class sp_counted_base
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{
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private:
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// typedef detail::lightweight_mutex mutex_type;
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public:
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sp_counted_base(): use_count_(1), weak_count_(1)
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{
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}
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virtual ~sp_counted_base() // nothrow
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{
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}
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// dispose() is called when use_count_ drops to zero, to release
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// the resources managed by *this.
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virtual void dispose() = 0; // nothrow
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// destruct() is called when weak_count_ drops to zero.
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virtual void destruct() // nothrow
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{
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delete this;
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}
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virtual void * get_deleter(std::type_info const & ti) = 0;
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void add_ref_copy()
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{
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#if defined(BOOST_HAS_THREADS)
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mutex_type::scoped_lock lock(mtx_);
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#endif
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++use_count_;
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}
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void add_ref_lock()
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{
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#if defined(BOOST_HAS_THREADS)
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mutex_type::scoped_lock lock(mtx_);
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#endif
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if(use_count_ == 0) boost::throw_exception(boost::bad_weak_ptr());
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++use_count_;
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}
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void release() // nothrow
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{
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{
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#if defined(BOOST_HAS_THREADS)
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mutex_type::scoped_lock lock(mtx_);
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#endif
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long new_use_count = --use_count_;
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if(new_use_count != 0) return;
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}
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dispose();
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weak_release();
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}
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void weak_add_ref() // nothrow
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{
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#if defined(BOOST_HAS_THREADS)
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mutex_type::scoped_lock lock(mtx_);
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#endif
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++weak_count_;
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}
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void weak_release() // nothrow
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{
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long new_weak_count;
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{
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#if defined(BOOST_HAS_THREADS)
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mutex_type::scoped_lock lock(mtx_);
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#endif
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new_weak_count = --weak_count_;
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}
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if(new_weak_count == 0)
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{
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destruct();
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}
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}
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long use_count() const // nothrow
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{
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#if defined(BOOST_HAS_THREADS)
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mutex_type::scoped_lock lock(mtx_);
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#endif
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return use_count_;
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}
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private:
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sp_counted_base(sp_counted_base const &);
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sp_counted_base & operator= (sp_counted_base const &);
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long use_count_; // #shared
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long weak_count_; // #weak + (#shared != 0)
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#if defined(BOOST_HAS_THREADS) || defined(BOOST_LWM_WIN32)
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mutable mutex_type mtx_;
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#endif
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};
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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template<class T> void cbi_call_constructor_hook(sp_counted_base * pn, T * px, checked_deleter<T> const &, int)
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{
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boost::sp_scalar_constructor_hook(px, sizeof(T), pn);
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}
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template<class T> void cbi_call_constructor_hook(sp_counted_base *, T * px, checked_array_deleter<T> const &, int)
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{
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boost::sp_array_constructor_hook(px);
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}
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template<class P, class D> void cbi_call_constructor_hook(sp_counted_base *, P const &, D const &, long)
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{
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}
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template<class T> void cbi_call_destructor_hook(sp_counted_base * pn, T * px, checked_deleter<T> const &, int)
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{
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boost::sp_scalar_destructor_hook(px, sizeof(T), pn);
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}
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template<class T> void cbi_call_destructor_hook(sp_counted_base *, T * px, checked_array_deleter<T> const &, int)
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{
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boost::sp_array_destructor_hook(px);
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}
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template<class P, class D> void cbi_call_destructor_hook(sp_counted_base *, P const &, D const &, long)
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{
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}
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#endif
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//
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// Borland's Codeguard trips up over the -Vx- option here:
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//
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#ifdef __CODEGUARD__
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# pragma option push -Vx-
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#endif
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template<class P, class D> class sp_counted_base_impl: public sp_counted_base
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{
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private:
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P ptr; // copy constructor must not throw
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D del; // copy constructor must not throw
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sp_counted_base_impl(sp_counted_base_impl const &);
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sp_counted_base_impl & operator= (sp_counted_base_impl const &);
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typedef sp_counted_base_impl<P, D> this_type;
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public:
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// pre: initial_use_count <= initial_weak_count, d(p) must not throw
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sp_counted_base_impl(P p, D d): ptr(p), del(d)
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{
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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detail::cbi_call_constructor_hook(this, p, d, 0);
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#endif
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}
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virtual void dispose() // nothrow
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{
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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detail::cbi_call_destructor_hook(this, ptr, del, 0);
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#endif
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del(ptr);
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}
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virtual void * get_deleter(std::type_info const & ti)
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{
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return ti == typeid(D)? &del: 0;
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}
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#if defined(BOOST_SP_USE_STD_ALLOCATOR)
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void * operator new(std::size_t)
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{
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return std::allocator<this_type>().allocate(1, static_cast<this_type *>(0));
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}
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void operator delete(void * p)
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{
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std::allocator<this_type>().deallocate(static_cast<this_type *>(p), 1);
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}
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#endif
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#if defined(BOOST_SP_USE_QUICK_ALLOCATOR)
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void * operator new(std::size_t)
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{
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return quick_allocator<this_type>::alloc();
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}
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void operator delete(void * p)
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{
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quick_allocator<this_type>::dealloc(p);
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}
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#endif
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};
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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int const shared_count_id = 0x2C35F101;
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int const weak_count_id = 0x298C38A4;
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#endif
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class weak_count;
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class shared_count
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{
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private:
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sp_counted_base * pi_;
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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int id_;
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#endif
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friend class weak_count;
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public:
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shared_count(): pi_(0) // nothrow
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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, id_(shared_count_id)
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#endif
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{
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}
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template<class P, class D> shared_count(P p, D d): pi_(0)
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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, id_(shared_count_id)
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#endif
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{
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#ifndef BOOST_NO_EXCEPTIONS
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try
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{
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pi_ = new sp_counted_base_impl<P, D>(p, d);
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}
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catch(...)
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{
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d(p); // delete p
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throw;
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}
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#else
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pi_ = new sp_counted_base_impl<P, D>(p, d);
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if(pi_ == 0)
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{
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d(p); // delete p
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boost::throw_exception(std::bad_alloc());
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}
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#endif
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}
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#ifndef BOOST_NO_AUTO_PTR
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// auto_ptr<Y> is special cased to provide the strong guarantee
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template<class Y>
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explicit shared_count(std::auto_ptr<Y> & r): pi_(new sp_counted_base_impl< Y *, checked_deleter<Y> >(r.get(), checked_deleter<Y>()))
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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, id_(shared_count_id)
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#endif
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{
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r.release();
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}
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#endif
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~shared_count() // nothrow
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{
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if(pi_ != 0) pi_->release();
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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id_ = 0;
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#endif
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}
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shared_count(shared_count const & r): pi_(r.pi_) // nothrow
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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, id_(shared_count_id)
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#endif
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{
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if(pi_ != 0) pi_->add_ref_copy();
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}
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explicit shared_count(weak_count const & r); // throws bad_weak_ptr when r.use_count() == 0
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shared_count & operator= (shared_count const & r) // nothrow
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{
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sp_counted_base * tmp = r.pi_;
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if(tmp != 0) tmp->add_ref_copy();
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if(pi_ != 0) pi_->release();
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pi_ = tmp;
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return *this;
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}
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void swap(shared_count & r) // nothrow
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{
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sp_counted_base * tmp = r.pi_;
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r.pi_ = pi_;
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pi_ = tmp;
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}
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long use_count() const // nothrow
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{
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return pi_ != 0? pi_->use_count(): 0;
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}
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bool unique() const // nothrow
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{
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return use_count() == 1;
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}
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friend inline bool operator==(shared_count const & a, shared_count const & b)
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{
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return a.pi_ == b.pi_;
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}
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friend inline bool operator<(shared_count const & a, shared_count const & b)
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{
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return std::less<sp_counted_base *>()(a.pi_, b.pi_);
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}
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void * get_deleter(std::type_info const & ti) const
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{
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return pi_? pi_->get_deleter(ti): 0;
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}
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};
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#ifdef __CODEGUARD__
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# pragma option pop
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#endif
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class weak_count
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{
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private:
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sp_counted_base * pi_;
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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int id_;
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#endif
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friend class shared_count;
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public:
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weak_count(): pi_(0) // nothrow
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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, id_(weak_count_id)
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#endif
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{
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}
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weak_count(shared_count const & r): pi_(r.pi_) // nothrow
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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, id_(shared_count_id)
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#endif
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{
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if(pi_ != 0) pi_->weak_add_ref();
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}
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weak_count(weak_count const & r): pi_(r.pi_) // nothrow
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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, id_(shared_count_id)
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#endif
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{
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if(pi_ != 0) pi_->weak_add_ref();
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}
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~weak_count() // nothrow
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{
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if(pi_ != 0) pi_->weak_release();
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
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id_ = 0;
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#endif
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}
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weak_count & operator= (shared_count const & r) // nothrow
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{
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sp_counted_base * tmp = r.pi_;
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if(tmp != 0) tmp->weak_add_ref();
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if(pi_ != 0) pi_->weak_release();
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pi_ = tmp;
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return *this;
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}
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weak_count & operator= (weak_count const & r) // nothrow
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{
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sp_counted_base * tmp = r.pi_;
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if(tmp != 0) tmp->weak_add_ref();
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if(pi_ != 0) pi_->weak_release();
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pi_ = tmp;
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return *this;
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}
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void swap(weak_count & r) // nothrow
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{
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sp_counted_base * tmp = r.pi_;
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r.pi_ = pi_;
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pi_ = tmp;
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}
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long use_count() const // nothrow
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{
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return pi_ != 0? pi_->use_count(): 0;
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}
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friend inline bool operator==(weak_count const & a, weak_count const & b)
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{
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return a.pi_ == b.pi_;
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}
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friend inline bool operator<(weak_count const & a, weak_count const & b)
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{
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return std::less<sp_counted_base *>()(a.pi_, b.pi_);
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}
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};
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inline shared_count::shared_count(weak_count const & r): pi_(r.pi_)
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#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
|
||||
, id_(shared_count_id)
|
||||
#endif
|
||||
{
|
||||
if(pi_ != 0)
|
||||
{
|
||||
pi_->add_ref_lock();
|
||||
}
|
||||
else
|
||||
{
|
||||
boost::throw_exception(boost::bad_weak_ptr());
|
||||
}
|
||||
}
|
||||
|
||||
} // namespace detail
|
||||
|
||||
} // namespace boost
|
||||
|
||||
#ifdef __BORLANDC__
|
||||
# pragma warn .8027 // Functions containing try are not expanded inline
|
||||
# pragma warn .8026 // Functions with excep. spec. are not expanded inline
|
||||
#endif
|
||||
|
||||
#endif // #ifndef BOOST_DETAIL_SHARED_COUNT_HPP_INCLUDED
|
||||
Loading…
Add table
Add a link
Reference in a new issue