boost::urls::url_view::url_view Constructor Synopsis Declared in header <boost/url/url_view.hpp> url_view() noexcept; Description Default constructed views refer to a string with zero length, which always remains valid. This matches the grammar for a relative-ref with an empty path and no query or fragment. url_view u; this->empty() == true Constant. Throws nothing. relative-ref = relative-part [ "?" query ] [ "#" fragment ] 4.2. Relative Reference (rfc3986)