6 #if defined CT_USE_STD_SHARED_PTR
10 using std::shared_ptr;
13 #elif defined CT_USE_TR1_SHARED_PTR
17 using std::tr1::shared_ptr;
20 #elif defined CT_USE_MSFT_SHARED_PTR
24 using std::tr1::shared_ptr;
27 #elif defined CT_USE_BOOST_SHARED_PTR
28 #include <boost/shared_ptr.hpp>
31 using boost::shared_ptr;
35 #error "No shared_ptr implementation available"