sqrt.h

00001 ///\file
00002 
00003 /******************************************************************************
00004 The MIT License(MIT)
00005 
00006 Embedded Template Library.
00007 https://github.com/ETLCPP/etl
00008 https://www.etlcpp.com
00009 
00010 Copyright(c) 2017 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_SQRT__
00032 #define __ETL_SQRT__
00033 
00034 #include <stddef.h>
00035 
00036 #include "platform.h "
00037 #include "type_traits.h "
00038 #include "constant.h "
00039 
00040 namespace etl 
00041 {
00042   //***************************************************************************
00043   /// Calculates the smallest value that, when squared, will be not greater than VALUE.
00044   //***************************************************************************
00045   template <const size_t VALUE, const size_t I = 1>
00046   struct sqrt
00047   {
00048     typedef typename etl::conditional<((I * I) > VALUE), 
00049                                       etl::constant<intmax_t, I - 1>,
00050                                       etl::sqrt<VALUE, I + 1> >::type type;
00051 
00052     enum value_type
00053     {
00054       // Recursive definition.
00055       value = type::value
00056     };
00057   };
00058 }
00059 
00060 #endif
00061