Method type operator/=

extern/boost/boost/rational.hpp:314–333

    }
    template <class T>
    BOOST_CXX14_CONSTEXPR typename boost::enable_if_c<rational_detail::is_compatible_integer<T, IntType>::value, rational&>::type operator/= (const T& i)
    {
       // Avoid repeated construction
       IntType const zero(0);

       if(i == zero) BOOST_THROW_EXCEPTION(bad_rational());
       if(num == zero) return *this;

       // Avoid overflow and preserve normalization
       IntType const gcd = integer::gcd(num, static_cast<IntType>(i));
       num /= gcd;
       den *= i / gcd;

       if(den < zero) {
          num = -num;
          den = -den;
       }

       return *this;
    }

    // Increment and decrement
    BOOST_CXX14_CONSTEXPR const rational& operator++() { num += den; return *this; }