* Shared (garbage collecting) pointers. Copied from Boost.

1 files changed, 474 insertions, 0 deletions

diff --git a/src/boost/shared_ptr.hpp b/src/boost/shared_ptr.hpp
new file mode 100644
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+++ b/src/boost/shared_ptr.hpp
@@ -0,0 +1,474 @@
+#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
+//
+//  Permission to copy, use, modify, sell and distribute this software
+//  is granted provided this copyright notice appears in all copies.
+//  This software is provided "as is" without express or implied
+//  warranty, and with no claim as to its suitability for any purpose.
+//
+//  See http://www.boost.org/libs/smart_ptr/shared_ptr.htm for documentation.
+//
+
+//#include <boost/config.hpp>   // for broken compiler workarounds
+
+#if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)
+#include <boost/detail/shared_ptr_nmt.hpp>
+#else
+
+#include <boost/assert.hpp>
+#include <boost/checked_delete.hpp>
+#include <boost/throw_exception.hpp>
+#include <boost/detail/shared_count.hpp>
+#include <boost/detail/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;
+};
+
+#endif
+
+// enable_shared_from_this support
+
+template<class T, class Y> void sp_enable_shared_from_this(boost::enable_shared_from_this<T> * pe, Y * px, shared_count const & pn)
+{
+    if(pe != 0) pe->_internal_weak_this._internal_assign(px, pn);
+}
+
+inline void sp_enable_shared_from_this(void const volatile *, void const volatile *, shared_count const &)
+{
+}
+
+} // 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(p, p, pn);
+    }
+
+    //
+    // 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(p, p, pn);
+    }
+
+//  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(tmp, tmp, pn);
+    }
+
+#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