get_deleter<> added.

[SVN r16365]

include/boost/detail/shared_count.hpp

@@ -29,6 +29,7 @@
 #include <functional>       // for std::less
 #include <exception>        // for std::exception
 #include <new>              // for std::bad_alloc
+#include <typeinfo>         // for std::type_info in get_deleter
 
 #ifdef __BORLANDC__
 # pragma warn -8026     // Functions with excep. spec. are not expanded inline
@@ -106,6 +107,8 @@ public:
         delete this;
     }
 
+    virtual void * get_deleter(std::type_info const & ti) = 0;
+
     void add_ref()
     {
 #if defined(BOOST_HAS_THREADS)
@@ -253,6 +256,11 @@ public:
         del(ptr);
     }
 
+    virtual void * get_deleter(std::type_info const & ti)
+    {
+        return ti == typeid(D)? &del: 0;
+    }
+
 #if defined(BOOST_SP_USE_STD_ALLOCATOR)
 
     void * operator new(std::size_t)
@@ -371,6 +379,11 @@ public:
     {
         return std::less<counted_base *>()(a.pi_, b.pi_);
     }
+
+    void * get_deleter(std::type_info const & ti) const
+    {
+        return pi_->get_deleter(ti);
+    }
 };
 
 #ifdef __CODEGUARD__

include/boost/shared_ptr.hpp

@@ -275,6 +275,11 @@ public:
         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)
 
@@ -364,6 +369,13 @@ template<class T> inline T * get_pointer(shared_ptr<T> const & p)
     return p.get();
 }
 
+// get_deleter (experimental)
+
+template<class D, class T> D * get_deleter(shared_ptr<T> const & p)
+{
+    return static_cast<D *>(p._internal_get_deleter(typeid(D)));
+}
+
 } // namespace boost
 
 #ifdef BOOST_MSVC