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108 lines
3.2 KiB
C++
108 lines
3.2 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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Copyright(c) 2014 jwellbelove
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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_math__
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#define __etl_math__
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#include <cstddef>
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namespace etl
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{
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//***************************************************************************
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///\ingroup Math
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/// The base generic log template.
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/// Defines 'value' as the log of the number at the specified base.
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/// The result is rounded down to the next integer.
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///\tparam N The number to find the log of.
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///\tparam BASE The base of the log.
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//***************************************************************************
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template <const size_t N, const size_t BASE>
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struct log
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{
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enum value_type
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{
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// Recursive definition.
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value = (N >= BASE) ? 1 + log<N / BASE, BASE>::value : 0
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};
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};
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//***************************************************************************
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///\ingroup Math
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/// Specialisation for N = 1
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//***************************************************************************
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template <const size_t BASE>
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struct log<1, BASE>
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{
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enum value_type
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{
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value = 0
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};
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};
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//***************************************************************************
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///\ingroup Math
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/// Specialisation for N = 0
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//***************************************************************************
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template <const size_t BASE>
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struct log<0, BASE>
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{
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enum value_type
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{
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value = 0
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};
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};
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//***************************************************************************
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///\ingroup Math
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/// The specialisation for base 2 logs.
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//***************************************************************************
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template <const size_t N>
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struct Log2
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{
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enum value_type
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{
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value = log<N, 2>::value
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};
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};
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//***************************************************************************
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///\ingroup Math
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/// The specialisation for base 10 logs.
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//***************************************************************************
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template <const size_t N>
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struct Log10
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{
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enum value_type
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{
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value = log<N, 10>::value
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};
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};
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}
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#endif
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