BOOST_EXCEPTION_DISABLE does not work in rational

[tower120]

BOOST_EXCEPTION_DISABLE have no effect with rational lib. Due to:

rational.hpp

// Input and output
template <typename IntType>
std::istream& operator>> (std::istream& is, rational<IntType>& r)
{
    using std::ios;

    IntType n = IntType(0), d = IntType(1);
    char c = 0;
    detail::resetter sentry(is);

    if ( is >> n )
    {
        if ( is.get(c) )
        {
            if ( c == '/' )
            {
                if ( is >> std::noskipws >> d )
                    try {
                        r.assign( n, d );
                    } catch ( bad_rational & ) {        // normalization fail
                        try { is.setstate(ios::failbit); }
                        catch ( ... ) {}  // don't throw ios_base::failure...
                        if ( is.exceptions() & ios::failbit )
                            throw;   // ...but the original exception instead
                        // ELSE: suppress the exception, use just error flags
                    }
            }
            else
                is.setstate( ios::failbit );
        }
    }

    return is;
}