move typed headers and implement FromRequest (#2094)

Co-authored-by: Rob Ede <robjtede@icloud.com>

src/http/header/expires.rs

@@ -0,0 +1,41 @@
+use super::{HttpDate, EXPIRES};
+
+crate::header! {
+    /// `Expires` header, defined in [RFC7234](http://tools.ietf.org/html/rfc7234#section-5.3)
+    ///
+    /// The `Expires` header field gives the date/time after which the
+    /// response is considered stale.
+    ///
+    /// The presence of an Expires field does not imply that the original
+    /// resource will change or cease to exist at, before, or after that
+    /// time.
+    ///
+    /// # ABNF
+    ///
+    /// ```text
+    /// Expires = HTTP-date
+    /// ```
+    ///
+    /// # Example values
+    /// * `Thu, 01 Dec 1994 16:00:00 GMT`
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use std::time::{SystemTime, Duration};
+    /// use actix_web::HttpResponse;
+    /// use actix_web::http::header::Expires;
+    ///
+    /// let mut builder = HttpResponse::Ok();
+    /// let expiration = SystemTime::now() + Duration::from_secs(60 * 60 * 24);
+    /// builder.insert_header(
+    ///     Expires(expiration.into())
+    /// );
+    /// ```
+    (Expires, EXPIRES) => [HttpDate]
+
+    test_expires {
+        // Test case from RFC
+        test_header!(test1, vec![b"Thu, 01 Dec 1994 16:00:00 GMT"]);
+    }
+}