:relfileprefix: ../../../ [#boost-urls-grammar-ref-01] = xref:boost.adoc[pass:[boost]]::xref:boost/urls.adoc[pass:[urls]]::xref:boost/urls/grammar.adoc[pass:[grammar]]::ref == Synopsis Declared in header `` [source,cpp,subs="verbatim,macros,-callouts"] ---- constexpr void ref(...) = delete; ----