Endian.h

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//============================================================================
//  Copyright (c) Kitware, Inc.
//  All rights reserved.
//  See LICENSE.txt for details.
//
//  This software is distributed WITHOUT ANY WARRANTY; without even
//  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
//  PURPOSE.  See the above copyright notice for more information.
//============================================================================
#ifndef vtk_m_io_internal_Endian_h
#define vtk_m_io_internal_Endian_h
 
#include <vtkm/Types.h>
 
#include <algorithm>
#include <vector>
 
namespace vtkm
{
namespace io
{
namespace internal
{
 
inline bool IsLittleEndian()
{
  static constexpr vtkm::Int16 i16 = 0x1;
  const vtkm::Int8* i8p = reinterpret_cast<const vtkm::Int8*>(&i16);
  return (*i8p == 1);
}
 
template <typename T>
inline void FlipEndianness(std::vector<T>& buffer)
{
  vtkm::UInt8* bytes = reinterpret_cast<vtkm::UInt8*>(&buffer[0]);
  const std::size_t tsize = sizeof(T);
  const std::size_t bsize = buffer.size();
  for (std::size_t i = 0; i < bsize; i++, bytes += tsize)
  {
    std::reverse(bytes, bytes + tsize);
  }
}
 
template <typename T, vtkm::IdComponent N>
inline void FlipEndianness(std::vector<vtkm::Vec<T, N>>& buffer)
{
  vtkm::UInt8* bytes = reinterpret_cast<vtkm::UInt8*>(&buffer[0]);
  const std::size_t tsize = sizeof(T);
  const std::size_t bsize = buffer.size();
  for (std::size_t i = 0; i < bsize; i++)
  {
    for (vtkm::IdComponent j = 0; j < N; j++, bytes += tsize)
    {
      std::reverse(bytes, bytes + tsize);
    }
  }
}
}
}
} // vtkm::io::internal
 
#endif //vtk_m_io_internal_Endian_h