getAnyPtr.h

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#ifndef FWCore_Utilities_getAnyPtr_h
#define FWCore_Utilities_getAnyPtr_h

#include <cassert>
#include <memory>

namespace edm {
  template <typename T>
  inline
  std::unique_ptr<T> getAnyPtr(void* p, int offset) {
    // A union is used to avoid possible copies during the triple cast that would otherwise be needed.   
    // std::unique_ptr<T> edp(static_cast<T*>(static_cast<void *>(static_cast<unsigned char *>(p) + offset)));   
    union {      
      void* vp;      
      unsigned char* ucp;    
      T* tp;     
    } pointerUnion;      
    assert(p != nullptr);
    pointerUnion.vp = p;     
    pointerUnion.ucp += offset;      
    std::unique_ptr<T> tp(pointerUnion.tp);
    return(std::move(tp));
  }
}

#endif