gistfile1.txt

template<class T>
T
number_cast(
    value const& jv,
    error_code& ec,
    typename std::enable_if<
        std::is_floating_point<T>::value
            >::type* = 0
    ) noexcept
{
    switch(jv.kind())
    {
    case kind::int64:
    {
        auto const i = jv.get_int64();
        auto const t = static_cast<T>(i);
        if(t != i)
            ec = error::not_exact;
        return t;
    }

    case kind::uint64:
    {
        auto const u = jv.get_uint64();
        auto const t = static_cast<T>(u);
        if(t != u)
            ec = error::not_exact;
        return t;
    }

    default:
    case kind::double_:
    {
        auto const d = jv.get_double();
        auto const t = static_cast<T>(d);
        if(t != d)
            ec = error::not_exact;
        return t;
    }
    }
}