fraction.hpp

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//=======================================================================
// Copyright (c)
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//=======================================================================
#ifndef PAAL_FRACTION_HPP
#define PAAL_FRACTION_HPP

#include "paal/utils/floating.hpp"

namespace paal {
namespace data_structures {

template <class A, class B> struct fraction {
    using num_type = A;
    using den_type = B;
    A num;
    B den;
    fraction(A num, B den) : num(num), den(den) {}
};

template <class A, class B, class C, class D>
bool operator<(const fraction<A, B> &f1, const fraction<C, D> &f2)
{
    return f1.num * f2.den < f2.num * f1.den;
}

template <class A, class B, class C, class D>
bool operator>(const fraction<A, B> &f1, const fraction<C, D> &f2)
{
    return f2 < f1;
}

template <class A, class B, class C, class D>
bool operator<=(const fraction<A, B> &f1, const fraction<C, D> &f2)
{
    return !(f2 < f1);
}

template <class A, class B, class C, class D>
bool operator>=(const fraction<A, B> &f1, const fraction<C, D> &f2)
{
    return !(f1 < f2);
}

template<class A, class B, class C, class D, class EPS = A>
bool are_fractions_equal(const fraction<A, B>& f1, const fraction<C, D>& f2, EPS eps = A{})
{
    auto x = f1.num * f2.den - f2.num * f1.den;
    utils::compare<decltype(x)> cmp(eps);
    return cmp.e(x, 0);
}

template <class A, class B>
fraction<A, B> make_fraction(A a, B b)
{
    return fraction<A, B>(a, b);
}

template<class A, class B, class C>
auto operator*(C c, const fraction<A, B>& f) {

    return make_fraction(c * f.num, f.den);
}

} 
} 

#endif // PAAL_FRACTION_HPP