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  #ifndef GMX_GPU_UTILS_DEVICEBUFFER_DATATYPE_H
  #define GMX_GPU_UTILS_DEVICEBUFFER_DATATYPE_H
  
  /*! \libinternal \file
   *  \brief Declares the DeviceBuffer data type.
   *
   *  \author Aleksei Iupinov <a.yupinov@gmail.com>
   *  \author Artem Zhmurov <zhmurov@gmail.com>
   *
   *  \inlibraryapi
   */
  
  #include "config.h"
  
  #include <memory>
  
  #include "gromacs/math/vectypes.h"
  
  #if GMX_GPU_CUDA
  
  //! \brief A device-side buffer of ValueTypes
  template<typename ValueType>
  using DeviceBuffer = ValueType*;
  
  #elif GMX_GPU_OPENCL
  
  #    include "gromacs/gpu_utils/gputraits_ocl.h"
  
  /*! \libinternal \brief
   * A minimal cl_mem wrapper that remembers its allocation type.
   * The only point is making template type deduction possible.
   */
  template<typename ValueType>
  class TypedClMemory
  {
  private:
      /*! \brief Underlying data
       *
       *  \todo Make it nullptr when there are no snew()'s around
       */
      cl_mem data_;
  
  public:
      //! \brief An assignment operator - the purpose is to make allocation/zeroing work
      TypedClMemory& operator=(cl_mem data)
      {
          data_ = data;
          return *this;
      }
      //! \brief Returns underlying cl_mem transparently
      operator cl_mem() { return data_; }
  };
  
  //! \libinternal \brief A device-side buffer of ValueTypes
  template<typename ValueType>
  using DeviceBuffer = TypedClMemory<ValueType>;
  
  #elif GMX_GPU_SYCL
  
  /*! \libinternal \brief
   * A minimal wrapper around \c cl::sycl::buffer to hide it away and simplify compilation.
   */
  template<typename ValueType>
  struct DeviceBuffer
  {
      class ClSyclBufferWrapper;
      std::unique_ptr<ClSyclBufferWrapper> buffer_;
  
      DeviceBuffer();
      ~DeviceBuffer();
      DeviceBuffer(DeviceBuffer<ValueType> const& src);
      DeviceBuffer(DeviceBuffer<ValueType>&& src) noexcept;
      DeviceBuffer& operator=(DeviceBuffer<ValueType> const& src);
      DeviceBuffer& operator=(DeviceBuffer<ValueType>&& src) noexcept;
  
      //! Helper function to get the size in bytes of a single element
      static constexpr size_t elementSize() { return sizeof(ValueType); }
  
      // Both explicit and implicit casts to void* are used in MPI+CUDA code, this stub is necessary for compilation.
      operator void*() const { throw; }
  
      //! Allow implicit conversion to bool to check buffer status for compatibility with other implementations.
      operator bool() const { return buffer_.get() != nullptr; }
  
      //! An assignment operator to allow resetting buffer by assigning nullptr to it. Necessary for compilation.
      DeviceBuffer& operator=(std::nullptr_t nullPtr);
  };
  
  // Must explicitly instantiate for some types.
  extern template struct DeviceBuffer<gmx::RVec>;
  
  #else
  
  //! \brief A device-side buffer of ValueTypes
  template<typename ValueType>
  using DeviceBuffer = void*;
  
  #endif
  
  #endif // GMX_GPU_UTILS_DEVICEBUFFER_DATATYPE_H
  