Function 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. Example url_view u; Postconditions this->empty() == true Complexity Constant. Exception Safety Throws nothing. BNF relative-ref = relative-part [ "?" query ] [ "#" fragment ] Specification 4.2. Relative Reference (rfc3986)