const_pointer_cast added.

[SVN r19147]

include/boost/intrusive_ptr.hpp

@@ -220,6 +220,11 @@ template<class T, class U> intrusive_ptr<T> static_pointer_cast(intrusive_ptr<U>
     return static_cast<T *>(p.get());
 }
 
+template<class T, class U> intrusive_ptr<T> const_pointer_cast(intrusive_ptr<U> const & p)
+{
+    return const_cast<T *>(p.get());
+}
+
 template<class T, class U> intrusive_ptr<T> dynamic_pointer_cast(intrusive_ptr<U> const & p)
 {
     return dynamic_cast<T *>(p.get());

include/boost/shared_ptr.hpp

@@ -48,6 +48,7 @@ namespace detail
 {
 
 struct static_cast_tag {};
+struct const_cast_tag {};
 struct dynamic_cast_tag {};
 struct polymorphic_cast_tag {};
 
@@ -68,6 +69,16 @@ 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
@@ -158,6 +169,11 @@ public:
     {
     }
 
+    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)
     {
@@ -351,6 +367,11 @@ template<class T, class U> shared_ptr<T> static_pointer_cast(shared_ptr<U> const
     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());