Method symbol

tests/catch.hpp:1715–1720

template <class Ratio>
std::string ratio_string<Ratio>::symbol() {
    Catch::ReusableStringStream rss;
    rss << '[' << Ratio::num << '/'
        << Ratio::den << ']';
    return rss.str();
}
template <>
struct ratio_string<std::atto> {
    static std::string symbol();