Return the query corresponding to these params
                pct_string_view
buffer() noexcept;            
        Declared in file <src/params_encoded_base.cpp> at line 58
This function returns the query string referenced by the container. The returned string may contain percent escapes.
assert( url_view( "?first=John&last=Doe" ).encoded_params().buffer() == "first=John&last=Doe" );
Constant.
Throws nothing.
query-params    = query-param *( "&" query-param )
query-param     = key [ "=" value ]
key             = *qpchar
value           = *( qpchar / "=" )