75 lines
2.4 KiB
C++
75 lines
2.4 KiB
C++
///\file
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/******************************************************************************
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The MIT License(MIT)
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Embedded Template Library.
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https://github.com/ETLCPP/etl
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https://www.etlcpp.com
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Copyright(c) 2017 John Wellbelove
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files(the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions :
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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******************************************************************************/
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#ifndef ETL_SQRT_INCLUDED
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#define ETL_SQRT_INCLUDED
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#include "platform.h"
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#include "type_traits.h"
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#include "constant.h"
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#include <stddef.h>
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namespace etl
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{
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//***************************************************************************
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/// Calculates the smallest value that, when squared, will be not greater than VALUE.
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//***************************************************************************
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template <size_t VALUE, size_t I = 1>
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struct sqrt
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{
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typedef typename etl::conditional<((I * I) > VALUE),
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etl::constant<intmax_t, I - 1>,
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etl::sqrt<VALUE, I + 1> >::type type;
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#if ETL_USING_CPP11
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static constexpr size_t value = type::value;
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#else
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enum
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{
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// Recursive definition.
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value = type::value
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};
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#endif
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};
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#if ETL_USING_CPP11
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template <size_t VALUE, size_t I>
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constexpr size_t sqrt<VALUE, I>::value;
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#endif
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#if ETL_USING_CPP17
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template <size_t VALUE, size_t I = 1>
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inline constexpr size_t sqrt_v = sqrt<VALUE, I>::value;
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#endif
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}
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#endif
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