Function rangeToString

external/catch.hpp:1827–1837

    namespace Detail {
        template<typename InputIterator, typename Sentinel = InputIterator>
        std::string rangeToString(InputIterator first, Sentinel last) {
            ReusableStringStream rss;
            rss << "{ ";
            if (first != last) {
                rss << ::Catch::Detail::stringify(*first);
                for (++first; first != last; ++first)
                    rss << ", " << ::Catch::Detail::stringify(*first);
            }
            rss << " }";
            return rss.str();
        }
    }

#ifdef __OBJC__