Return the fragment
<include/boost/url/url_view_base.hpp>
pct_string_view
encoded_fragment() const noexcept;
This function returns the fragment as a string with percent-escapes. Ownership is not transferred; the string returned references the underlying character buffer, which must remain valid or else undefined behavior occurs.
assert( url_view( "http://www.example.com/index.htm#a%2D1" ).encoded_fragment() == "a%2D1" );
fragment = *( pchar / "/" / "?" )
pchar = unreserved / pct-encoded / sub-delims / ":" / "@"
fragment , has_fragment .