Common/interface/RefToPtr.h

0001 #ifndef DataFormats_Common_RefToPtr_h
0002 #define DataFormats_Common_RefToPtr_h
0003
0004 /*----------------------------------------------------------------------
0005
0006 Ref: A function template for conversion from Ref to Ptr
0007
0008 ----------------------------------------------------------------------*/
0009 /*
0010     ----------------------------------------------------------------------*/
0011
0012 #include "DataFormats/Common/interface/Ref.h"
0013 #include "DataFormats/Common/interface/RefTraits.h"
0014 #include "DataFormats/Common/interface/Ptr.h"
0015
0016 namespace edm {
0017   template <typename C>
0018   Ptr<typename C::value_type> refToPtr(
0019       Ref<C, typename C::value_type, refhelper::FindUsingAdvance<C, typename C::value_type> > const& ref) {
0020     typedef typename C::value_type T;
0021     if (ref.isNull()) {
0022       return Ptr<T>();
0023     }
0024     if (ref.isTransient()) {
0025       return Ptr<T>(ref.get(), ref.key());
0026     } else {
0027       //Another thread could change this value so get only once
0028       EDProductGetter const* getter = ref.productGetter();
0029       if (getter) {
0030         return Ptr<T>(ref.id(), ref.key(), getter);
0031       }
0032     }
0033     return Ptr<T>(ref.id(), ref.get(), ref.key());
0034   }
0035 }  // namespace edm
0036 #endif