[#boost-urls-string_token-is_token] = xref:boost.adoc[boost]::xref:boost/urls.adoc[urls]::xref:boost/urls/string_token.adoc[string_token]::is_token :relfileprefix: ../../../ :mrdocs: Trait to determine if a type is a string token == Synopsis Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/grammar/string_token.hpp#L127[boost/url/grammar/string_token.hpp]>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- template<class T> using is_token = /* implementation-defined */::xref:boost/urls/string_token/implementation_defined/is_token.adoc[is_token]<T>; ---- == Description This trait returns `true` if `T` is a valid xref:boost/urls/string_token/StringToken.adoc[StringToken] type, and `false` otherwise. === Example [,cpp] ---- static_assert( string_token::is_token::value ); ---- [.small]#Created with https://www.mrdocs.com[MrDocs]#