[#boost-urls-grammar-ref-02] = xref:boost.adoc[boost]::xref:boost/urls.adoc[urls]::xref:boost/urls/grammar.adoc[grammar]::ref :relfileprefix: ../../../ :mrdocs: Return a reference to a character set == Synopsis Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/grammar/charset.hpp#L251[boost/url/grammar/charset.hpp]>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- template<xref:boost/urls/grammar/CharSet.adoc[CharSet] CS> constexpr /* implementation-defined */::xref:boost/urls/grammar/implementation_defined/charset_ref.adoc[charset_ref]<CS> ref(CS const& cs) noexcept; ---- == Description This function returns a character set which references the specified object. This is used to reduce the number of bytes of storage (`sizeof`) required by a combinator when it stores a copy of the object. Ownership of the object is not transferred; the caller is responsible for ensuring the lifetime of the object is extended until it is no longer referenced. For best results, `ref` should only be used with compile‐time constants. [.small]#Created with https://www.mrdocs.com[MrDocs]#