factorial.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_FACTORIAL__
00032 #define __ETL_FACTORIAL__
00033 
00034 #include <stddef.h>
00035 
00036 #include "platform.h "
00037 
00038 ///\defgroup factorial factorial
00039 /// fibonacci<N> : Calculates the Nth factorial value.
00040 ///\ingroup maths
00041 
00042 namespace etl 
00043 {
00044   //***************************************************************************
00045   ///\ingroup fibonacci
00046   /// Defines <b>value</b> as the Nth factorial number.
00047   ///\tparam N The number to find the factorial value of.
00048   //***************************************************************************
00049   template <size_t N>
00050   struct factorial
00051   {
00052     static const size_t value = N * factorial<N - 1>::value;
00053   };
00054 
00055   //***************************************************************************
00056   // Specialisation for N = 0
00057   //***************************************************************************
00058   template <>
00059   struct factorial<0>
00060   {
00061     static const size_t value = 1;
00062   };
00063 }
00064 
00065 #endif
00066