107 lines
3.0 KiB
C
107 lines
3.0 KiB
C
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// Copyright (c) 2006-2007 Max-Planck-Institute Saarbruecken (Germany).
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// All rights reserved.
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//
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// This file is part of CGAL (www.cgal.org)
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//
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// $URL: https://github.com/CGAL/cgal/blob/v5.1/Algebraic_foundations/include/CGAL/Rational_traits.h $
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// $Id: Rational_traits.h 0779373 2020-03-26T13:31:46+01:00 Sébastien Loriot
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// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
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//
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//
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// Author(s) : Michael Hemmer <hemmer@mpi-inf.mpg.de>
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//
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// =============================================================================
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// This file is for backward compatibility
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// Rational_traits will be replaced by Fraction_traits
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#ifndef CGAL_RATIONAL_TRAITS_H
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#define CGAL_RATIONAL_TRAITS_H
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#include <CGAL/number_type_basic.h>
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#include <CGAL/Fraction_traits.h>
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#include <CGAL/is_convertible.h>
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#include <boost/utility/enable_if.hpp>
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namespace CGAL {
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namespace internal{
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template <class Rational, bool >
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struct Rational_traits_base
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{
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typedef Rational RT;
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const RT& numerator (const Rational& r) const { return r; }
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RT denominator (const Rational&) const { return RT(1); }
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template<class T>
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Rational make_rational(const T & x) const
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{ return x; }
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template<class T, class U>
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Rational make_rational(const std::pair<T, U> & x) const
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{ return make_rational(x.first, x.second); }
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Rational make_rational(const RT & n, const RT & d) const
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{ return n / d; }
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};
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template <class Rational>
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struct Rational_traits_base<Rational, true>
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{
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private:
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typedef Fraction_traits<Rational> FT;
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typedef typename FT::Decompose Decomose;
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typedef typename FT::Compose Compose;
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public:
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typedef typename FT::Numerator_type RT;
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RT numerator (const Rational& r) const {
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RT num,den;
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Decomose()(r,num,den);
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return num;
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}
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RT denominator (const Rational& r) const {
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RT num,den;
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Decomose()(r,num,den);
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return den;
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}
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template<class T>
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Rational make_rational(const T & x) const
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{ return x; }
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template<class T, class U>
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Rational make_rational(const std::pair<T, U> & x) const
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{ return make_rational(x.first, x.second); }
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template<class N,class D>
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Rational make_rational(const N& n, const D& d,typename boost::enable_if_c<is_implicit_convertible<N,RT>::value&&is_implicit_convertible<D,RT>::value,int>::type=0) const
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{ return Compose()(n,d); }
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template<class N,class D>
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Rational make_rational(const N& n, const D& d,typename boost::enable_if_c<!is_implicit_convertible<N,RT>::value||!is_implicit_convertible<D,RT>::value,int>::type=0) const
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{ return n/d; } // Assume that n or d is already a fraction
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};
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}// namespace internal
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// use Fraction_traits if Is_fraction && Num and Den are the same
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template <class T>
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class Rational_traits
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: public internal::Rational_traits_base<T,
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::boost::is_same<typename Fraction_traits<T>::Is_fraction,Tag_true>::value
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&&
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::boost::is_same<
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typename Fraction_traits<T>::Numerator_type,
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typename Fraction_traits<T>::Denominator_type
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>::value >
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{};
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} //namespace CGAL
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#endif // CGAL_RATIONAL_TRAITS_H
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// EOF
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