:relfileprefix: ../../../ [#boost-urls-implementation_defined-named_arg] == xref:boost.adoc[pass:[boost]]::xref:boost/urls.adoc[pass:[urls]]::xref:boost/urls/implementation_defined.adoc[pass:[implementation_defined]]::named_arg === Synopsis Declared in header `` [source,cpp,subs="verbatim,macros,-callouts"] ---- template using named_arg = detail::named_arg; ----