Fix #1106.

[SVN r45068]

include/boost/intrusive_ptr.hpp

@@ -23,8 +23,19 @@
 #include <boost/assert.hpp>
 #include <boost/detail/workaround.hpp>
 
+#if !defined( BOOST_NO_SFINAE )
+#include <boost/detail/sp_convertible.hpp>
+#endif
+
 #include <functional>           // for std::less
+
+#if !defined(BOOST_NO_IOSTREAM)
+#if !defined(BOOST_NO_IOSFWD)
 #include <iosfwd>               // for std::basic_ostream
+#else
+#include <ostream>
+#endif
+#endif
 
 
 namespace boost
@@ -66,9 +77,19 @@ public:
 
 #if !defined(BOOST_NO_MEMBER_TEMPLATES) || defined(BOOST_MSVC6_MEMBER_TEMPLATES)
 
-    template<class U> intrusive_ptr(intrusive_ptr<U> const & rhs): p_(rhs.get())
+    template<class U>
+#if !defined( BOOST_NO_SFINAE )
+
+    intrusive_ptr( intrusive_ptr<U> const & rhs, typename detail::sp_enable_if_convertible<U,T>::type = detail::sp_empty() )
+
+#else
+
+    intrusive_ptr( intrusive_ptr<U> const & rhs )
+
+#endif
+    : p_( rhs.get() )
     {
-        if(p_ != 0) intrusive_ptr_add_ref(p_);
+        if( p_ != 0 ) intrusive_ptr_add_ref( p_ );
     }
 
 #endif
@@ -246,7 +267,9 @@ template<class T, class U> intrusive_ptr<T> dynamic_pointer_cast(intrusive_ptr<U
 
 // operator<<
 
-#if defined(__GNUC__) &&  (__GNUC__ < 3)
+#if !defined(BOOST_NO_IOSTREAM)
+
+#if defined(BOOST_NO_TEMPLATED_IOSTREAMS) || ( defined(__GNUC__) &&  (__GNUC__ < 3) )
 
 template<class Y> std::ostream & operator<< (std::ostream & os, intrusive_ptr<Y> const & p)
 {
@@ -275,6 +298,8 @@ template<class E, class T, class Y> std::basic_ostream<E, T> & operator<< (std::
 
 #endif // __GNUC__ < 3
 
+#endif // !defined(BOOST_NO_IOSTREAM)
+
 } // namespace boost
 
 #ifdef BOOST_MSVC