endianness.h

00001 ///\file
00002 
00003 /******************************************************************************
00004 The MIT License(MIT)
00005 
00006 Embedded Template Library.
00007 https://github.com/ETLCPP/etl
00008 http://www.etlcpp.com
00009 
00010 Copyright(c) 2014 jwellbelove
00011 
00012 Permission is hereby granted, free of charge, to any person obtaining a copy
00013 of this software and associated documentation files(the "Software"), to deal
00014 in the Software without restriction, including without limitation the rights
00015 to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
00016 copies of the Software, and to permit persons to whom the Software is
00017 furnished to do so, subject to the following conditions :
00018 
00019 The above copyright notice and this permission notice shall be included in all
00020 copies or substantial portions of the Software.
00021 
00022 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00023 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00024 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
00025 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00026 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00027 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00028 SOFTWARE.
00029 ******************************************************************************/
00030 
00031 #ifndef __ETL_ENDIAN__
00032 #define __ETL_ENDIAN__
00033 
00034 #include <stdint.h>
00035 
00036 #include "platform.h "
00037 #include "enum_type.h "
00038 
00039 ///\defgroup endian endian
00040 /// Constants & utilities for endianess
00041 ///\ingroup utilities
00042 
00043 namespace etl
00044 {
00045   //***************************************************************************
00046   /// Constants to denote endianness of operations.
00047   ///\ingroup endian
00048   //***************************************************************************
00049   struct endian
00050   {
00051     enum enum_type
00052     {
00053       little,
00054       big,
00055       native
00056     };
00057 
00058     ETL_DECLARE_ENUM_TYPE(endian, int)
00059     ETL_ENUM_TYPE(little, "little")
00060     ETL_ENUM_TYPE(big,    "big")
00061     ETL_ENUM_TYPE(native, "native")
00062     ETL_END_ENUM_TYPE
00063   };
00064 
00065   //***************************************************************************
00066   /// Checks the endianness of the platform.
00067   ///\ingroup endian
00068   //***************************************************************************
00069   struct endianness
00070   {
00071     endianness()
00072       : ETL_ENDIAN_TEST(0x0011223344556677)
00073     {
00074     }
00075 
00076     endian operator ()() const
00077     {
00078       return endian(*this);
00079     }
00080 
00081     operator endian() const
00082     {
00083       return (*reinterpret_cast<const uint32_t*>(&ETL_ENDIAN_TEST) == 0x44556677) ? endian::little : endian::big;
00084     }
00085 
00086   private:
00087 
00088     const uint64_t ETL_ENDIAN_TEST;
00089   };
00090 }
00091 
00092 #endif
00093