...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Return true if the url is empty.
bool empty() const;
The empty string matches the relative-ref grammar.
assert( url_view( "" ).empty() );
Constant.
Throws nothing.
relative-ref = relative-part [ "?" query ] [ "#" fragment ] relative-part = "//" authority path-abempty / path-absolute / path-noscheme / path-empty