EndianConversions.h

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//     ____   ______ __
//    / __ \ / ____// /
//   / /_/ // /    / /
//  / ____// /___ / /___   PixInsight Class Library
// /_/     \____//_____/   PCL 2.7.0
// ----------------------------------------------------------------------------
// pcl/EndianConversions.h - Released 2024-06-18T15:48:54Z
// ----------------------------------------------------------------------------
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// ----------------------------------------------------------------------------
 
#ifndef __PCL_EndianConversions_h
#define __PCL_EndianConversions_h
 
 
#include <pcl/Defs.h>
 
#include <pcl/Math.h>
 
namespace pcl
{
 
// ----------------------------------------------------------------------------
 
inline uint16 BigToLittleEndian( uint16 x )
{
   return (x << 8) | (x >> 8);
}
 
inline uint32 BigToLittleEndian( uint32 x )
{
   return (RotL( x, 8 ) & 0x00ff00ffu) | (RotR( x, 8 ) & 0xff00ff00u);
 
}
 
inline uint64 BigToLittleEndian( uint64 x )
{
   return (uint64( BigToLittleEndian( uint32( x ) ) ) << 32) | uint64( BigToLittleEndian( uint32( x >> 32 ) ) );
}
 
template <typename T> inline T LittleToBigEndian( T x )
{
   return BigToLittleEndian( x );
}
 
// ----------------------------------------------------------------------------
 
union __pcl_endian_check__ { uint32 w; uint8 b[ sizeof( uint32 ) ]; };
 
constexpr __pcl_endian_check__ __pcl_endian_check_sample__ = { 0xdeadbeef };
 
#ifdef __clang__
 
inline bool IsLittleEndianMachine()
{
   return __pcl_endian_check_sample__.b[0] == 0xef;
}
 
inline bool IsBigEndianMachine()
{
   return __pcl_endian_check_sample__.b[0] == 0xde;
}
 
#else
 
// Clang fails here with "read of member 'b' of union with active member 'w' is
// not allowed in a constant expression".
 
constexpr bool IsLittleEndianMachine()
{
   return __pcl_endian_check_sample__.b[0] == 0xef;
}
 
constexpr bool IsBigEndianMachine()
{
   return __pcl_endian_check_sample__.b[0] == 0xde;
}
 
#endif // __clang__
 
// ----------------------------------------------------------------------------
 
} // pcl
 
#endif   // __PCL_EndianConversions_h
 
// ----------------------------------------------------------------------------
// EOF pcl/EndianConversions.h - Released 2024-06-18T15:48:54Z