endian.hh
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00001 #ifndef __UTILMM_SYSTEM_ENDIAN_HH
00002 #define __UTILMM_SYSTEM_ENDIAN_HH
00003 
00004 #include <utilmm/config/config.h>
00005 #include <boost/integer.hpp>
00006 
00007 namespace utilmm
00008 {
00013     namespace endian
00014     {
00015         namespace details {
00016             template<int size> struct type_from_size
00017             { typedef typename boost::uint_t<size>::least least; };
00018             template<> struct type_from_size<64>
00019             { typedef uint64_t least; };
00020 
00021             template<int size, typename D>
00022             void swap_helper(const D data, D& buffer);
00023 
00024             template<> inline void swap_helper<1, uint8_t>(const uint8_t data, uint8_t& buffer)
00025             { buffer = data; }
00026             template<> inline void swap_helper<2, uint16_t>(const uint16_t data, uint16_t& buffer)
00027             { buffer = ((data >> 8) & 0xFF) | ((data << 8) & 0xFF00); }
00028             template<> inline void swap_helper<4, uint32_t>(const uint32_t data, uint32_t& buffer)
00029             { buffer = ((data & 0xFF000000) >> 24) | ((data & 0x00FF0000) >> 8) | ((data & 0xFF) << 24) | ((data & 0xFF00) << 8); }
00030             template<> inline void swap_helper<8, uint64_t>(const uint64_t data, uint64_t& buffer)
00031             { 
00032                 const uint32_t 
00033                       src_low (data & 0xFFFFFFFF)
00034                     , src_high(data >> 32);
00035 
00036                 uint32_t dst_low, dst_high;
00037                 swap_helper<4, uint32_t>( src_high, dst_low );
00038                 swap_helper<4, uint32_t>( src_low, dst_high );
00039                 
00040                 buffer = static_cast<uint64_t>(dst_high) << 32 | dst_low;
00041             }
00042         }
00043 
00044         /* Returns in \c buffer the value of \c data with endianness swapped */
00045         template<typename S>
00046         inline void swap(const S data, S& buffer)
00047         { 
00048             typedef typename details::type_from_size<sizeof(S) * 8>::least T;
00049             details::swap_helper<sizeof(S), T> (reinterpret_cast<const T&>(data), reinterpret_cast<T&>(buffer)); 
00050         }
00051 
00052         /* Returns the value of \c data with endianness swapped */
00053         template<typename S>
00054         inline S swap(const S data)
00055         { S ret;
00056             swap(data, ret);
00057             return ret;
00058         }
00059 
00060 #ifdef WORDS_BIGENDIAN
00061 
00063         template<typename S>
00064         inline void to_big(const S source, S& dest) { dest = source; }
00067         template<typename S>
00068         inline S to_big(const S source) { return source; }
00071         template<typename S>
00072         inline void to_little(const S source, S& dest) { swap<S>(source, dest); }
00075         template<typename S>
00076         inline S to_little(const S source) { return swap<S>(source); }
00077 #else
00078         template<typename S>
00079         inline void to_big(const S source, S& dest) { swap<S>(source, dest); }
00080         template<typename S>
00081         inline S to_big(const S source) { return swap<S>(source); }
00082         template<typename S>
00083         inline void to_little(const S source, S& dest) { dest = source; }
00084         template<typename S>
00085         inline S to_little(const S source) { return source; }
00086 #endif
00087 
00090         template<typename S>
00091         inline void from_network(const S source, S& dest) { to_network(source, dest); }
00094         template<typename S>
00095         inline S from_network(const S source) { return to_network(source); }
00098         template<typename S>
00099         inline void from_little(const S source, S& dest) { to_little(source, dest); }
00102         template<typename S>
00103         inline S from_little(const S source) { return to_little(source); }
00106         template<typename S>
00107         inline void from_big(const S source, S& dest) { to_big(source, dest); }
00110         template<typename S>
00111         inline S from_big(const S source) { return to_big(source); }
00112 
00113         template<typename S>
00114         inline void to_network(const S source, S& dest) { return to_big(source, dest); }
00115         template<typename S>
00116         inline S to_network(const S source) { return to_big(source); }
00117     }
00118 }
00119 
00120 #endif
00121 


utilmm
Author(s): Sylvain Joyeux/sylvain.joyeux@m4x.org
autogenerated on Mon Oct 6 2014 03:17:01