Framework/interface/CacheHandle.h

0001 #ifndef FWCore_Framework_CacheHandle_h
0002 #define FWCore_Framework_CacheHandle_h
0003
0004 /** \class edm::CacheHandle
0005
0006 \author W. David Dagenhart, created 25 March, 2021
0007
0008 */
0009
0010 #include "FWCore/Utilities/interface/Exception.h"
0011
0012 namespace edm {
0013
0014   template <typename T>
0015   class CacheHandle {
0016   public:
0017     CacheHandle() : data_(nullptr) {}
0018     CacheHandle(T const* data) : data_(data) {}
0019
0020     T const* get() const {
0021       if (!isValid()) {
0022         throw cms::Exception("InvalidCache") << "CacheHandle is invalid";
0023       }
0024       return data_;
0025     }
0026     T const* operator->() const { return get(); }
0027     T const& operator*() const { return *get(); }
0028
0029     bool isValid() const { return data_ != nullptr; }
0030
0031   private:
0032     T const* data_;
0033   };
0034 }  // namespace edm
0035 #endif