Vary header, defined in RFC7231
The "Vary" header field in a response describes what parts of a
request message, aside from the method, Host header field, and
request target, might influence the origin server's process for
selecting and representing this response. The value consists of
either a single asterisk ("*") or a list of header field names
(case-insensitive).
Vary = "*" / 1#field-name
accept-encoding, accept-language
use headers::Vary;
let vary = Vary::any();
Create a new Very: * header.
Check if this includes *.
Iterate the header names of this Vary.
Formats the value using the given formatter. Read more
Performs copy-assignment from source. Read more
This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=.