// endian_swap.hpp

//           Copyright Mike Patterson 2004 - 2011.
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)

#ifndef BOOST_ENDIAN_SWAP_HPP
#define BOOST_ENDIAN_SWAP_HPP

#include <boost/integer.hpp>

namespace boost {
namespace endian {
namespace detail {

template<typename ::std::size_t>
class endian_swapper
{
public:
   template<typename T>
   static void swap(T& value) {/*no-op*/}
};

template<>
class endian_swapper<2>
{
public:
   typedef uint16_t value_type;

   template<typename T>
   static void swap(T& value) {do_swap(reinterpret_cast<value_type&>(value));}

private:
   static void do_swap(value_type& value) {value = (value >> 8) | (value << 8);}
};

template<>
class endian_swapper<4>
{
public:
   typedef uint32_t value_type;

   template<typename T>
   static void swap(T& value) {do_swap(reinterpret_cast<value_type&>(value));}

private:
   static void do_swap(value_type& value)
   {
      value =  (value >> 0x18)
            | ((value >> 0x08) & 0x0000FF00)
            | ((value << 0x08) & 0x00FF0000)
            |  (value << 0x18);
   }
};

template<>
class endian_swapper<8>
{
public:
   typedef uint64_t value_type;

   template<typename T>
   static void swap(T& value) {do_swap(reinterpret_cast<value_type&>(value));}

private:
   static void do_swap(value_type& value)
   {
      value =  (value >> 0x38)
            | ((value >> 0x28) & 0x000000000000FF00)
            | ((value >> 0x18) & 0x0000000000FF0000)
            | ((value >> 0x08) & 0x00000000FF000000)
            | ((value << 0x08) & 0x000000FF00000000)
            | ((value << 0x18) & 0x0000FF0000000000)
            | ((value << 0x28) & 0x00FF000000000000)
            |  (value << 0x38);
   }
};

} // namespace detail

template<typename T>
inline void swap(T& value) {detail::endian_swapper<sizeof(T)>::swap(value);}

} // namespace endian
} // namespace boost

#endif // BOOST_ENDIAN_SWAP_HPP