[#4A251B015BDB8B3B6A26622863076F9284328BDD]
Return the last segment
std::string back() const noexcept;
this->empty() == false
assert( url_view( "/path/to/file.txt" ).segments().back() == "file.txt" );
this->empty() == false
return *--end();
Linear in `this->back().size()`.
Calls to allocate may throw.