Implement the Header trait

src/auth/authorization.rs

@@ -1,6 +1,6 @@
 use crate::auth::AuthenticationScheme;
 use crate::bail_status as bail;
-use crate::headers::{HeaderName, HeaderValue, Headers, AUTHORIZATION};
+use crate::headers::{Header, HeaderName, HeaderValue, Headers, AUTHORIZATION};
 
 /// Credentials to authenticate a user agent with a server.
 ///
@@ -78,7 +78,7 @@ impl Authorization {
 
     /// Get the `HeaderName`.
     pub fn name(&self) -> HeaderName {
-        AUTHORIZATION
+        self.header_name()
     }
 
     /// Get the `HeaderValue`.
@@ -110,6 +110,16 @@ impl Authorization {
     }
 }
 
+impl Header for Authorization {
+    fn header_name(&self) -> HeaderName {
+        AUTHORIZATION
+    }
+
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;

src/auth/basic_auth.rs

@@ -113,6 +113,16 @@ impl BasicAuth {
     }
 }
 
+impl crate::headers::Header for BasicAuth {
+    fn header_name(&self) -> HeaderName {
+        AUTHORIZATION
+    }
+
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;

src/auth/www_authenticate.rs

@@ -132,6 +132,16 @@ impl WwwAuthenticate {
     }
 }
 
+impl crate::headers::Header for WwwAuthenticate {
+    fn header_name(&self) -> HeaderName {
+        WWW_AUTHENTICATE
+    }
+
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;

src/cache/age.rs

@@ -95,6 +95,16 @@ impl ToHeaderValues for Age {
     }
 }
 
+impl crate::headers::Header for Age {
+    fn header_name(&self) -> HeaderName {
+        AGE
+    }
+
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;

src/cache/cache_control/cache_control.rs

@@ -104,6 +104,15 @@ impl CacheControl {
     }
 }
 
+impl crate::headers::Header for CacheControl {
+    fn header_name(&self) -> HeaderName {
+        CACHE_CONTROL
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl IntoIterator for CacheControl {
     type Item = CacheDirective;
     type IntoIter = IntoIter;

src/cache/clear_site_data/mod.rs

@@ -249,6 +249,15 @@ impl Debug for ClearSiteData {
     }
 }
 
+impl crate::headers::Header for ClearSiteData {
+    fn header_name(&self) -> HeaderName {
+        CLEAR_SITE_DATA
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use crate::cache::{ClearDirective, ClearSiteData};

src/cache/expires.rs

@@ -90,6 +90,15 @@ impl Expires {
     }
 }
 
+impl crate::headers::Header for Expires {
+    fn header_name(&self) -> HeaderName {
+        EXPIRES
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl ToHeaderValues for Expires {
     type Iter = option::IntoIter<HeaderValue>;
     fn to_header_values(&self) -> crate::Result<Self::Iter> {

src/conditional/etag.rs

@@ -130,6 +130,15 @@ impl ETag {
     }
 }
 
+impl crate::headers::Header for ETag {
+    fn header_name(&self) -> HeaderName {
+        ETAG
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl Display for ETag {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {

src/conditional/if_match.rs

@@ -134,6 +134,15 @@ impl IfMatch {
     }
 }
 
+impl crate::headers::Header for IfMatch {
+    fn header_name(&self) -> HeaderName {
+        IF_MATCH
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl IntoIterator for IfMatch {
     type Item = ETag;
     type IntoIter = IntoIter;

src/conditional/if_modified_since.rs

@@ -93,6 +93,15 @@ impl ToHeaderValues for IfModifiedSince {
     }
 }
 
+impl crate::headers::Header for IfModifiedSince {
+    fn header_name(&self) -> HeaderName {
+        IF_MODIFIED_SINCE
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;

src/conditional/if_none_match.rs

@@ -140,6 +140,15 @@ impl IfNoneMatch {
     }
 }
 
+impl crate::headers::Header for IfNoneMatch {
+    fn header_name(&self) -> HeaderName {
+        IF_NONE_MATCH
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl IntoIterator for IfNoneMatch {
     type Item = ETag;
     type IntoIter = IntoIter;

src/conditional/if_unmodified_since.rs

@@ -85,6 +85,15 @@ impl IfUnmodifiedSince {
     }
 }
 
+impl crate::headers::Header for IfUnmodifiedSince {
+    fn header_name(&self) -> HeaderName {
+        IF_UNMODIFIED_SINCE
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl ToHeaderValues for IfUnmodifiedSince {
     type Iter = option::IntoIter<HeaderValue>;
     fn to_header_values(&self) -> crate::Result<Self::Iter> {

src/conditional/last_modified.rs

@@ -84,6 +84,15 @@ impl LastModified {
     }
 }
 
+impl crate::headers::Header for LastModified {
+    fn header_name(&self) -> HeaderName {
+        LAST_MODIFIED
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl ToHeaderValues for LastModified {
     type Iter = option::IntoIter<HeaderValue>;
     fn to_header_values(&self) -> crate::Result<Self::Iter> {

src/conditional/vary.rs

@@ -140,6 +140,15 @@ impl Vary {
     }
 }
 
+impl crate::headers::Header for Vary {
+    fn header_name(&self) -> HeaderName {
+        VARY
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl IntoIterator for Vary {
     type Item = HeaderName;
     type IntoIter = IntoIter;

src/content/accept.rs

@@ -189,6 +189,15 @@ impl Accept {
     }
 }
 
+impl crate::headers::Header for Accept {
+    fn header_name(&self) -> HeaderName {
+        ACCEPT
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl IntoIterator for Accept {
     type Item = MediaTypeProposal;
     type IntoIter = IntoIter;

src/content/accept_encoding.rs

@@ -182,6 +182,15 @@ impl AcceptEncoding {
     }
 }
 
+impl crate::headers::Header for AcceptEncoding {
+    fn header_name(&self) -> HeaderName {
+        ACCEPT_ENCODING
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl IntoIterator for AcceptEncoding {
     type Item = EncodingProposal;
     type IntoIter = IntoIter;

src/content/content_encoding.rs

@@ -80,6 +80,15 @@ impl ContentEncoding {
     }
 }
 
+impl crate::headers::Header for ContentEncoding {
+    fn header_name(&self) -> HeaderName {
+        CONTENT_ENCODING
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl ToHeaderValues for ContentEncoding {
     type Iter = option::IntoIter<HeaderValue>;
     fn to_header_values(&self) -> crate::Result<Self::Iter> {

src/content/content_length.rs

@@ -80,6 +80,15 @@ impl ContentLength {
     }
 }
 
+impl crate::headers::Header for ContentLength {
+    fn header_name(&self) -> HeaderName {
+        CONTENT_LENGTH
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;

src/content/content_location.rs

@@ -99,6 +99,15 @@ impl ContentLocation {
     }
 }
 
+impl crate::headers::Header for ContentLocation {
+    fn header_name(&self) -> HeaderName {
+        CONTENT_LOCATION
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;

src/content/content_type.rs

@@ -91,6 +91,15 @@ impl ContentType {
     }
 }
 
+impl crate::headers::Header for ContentType {
+    fn header_name(&self) -> HeaderName {
+        CONTENT_TYPE
+    }
+    fn header_value(&self) -> HeaderValue {
+        self.value()
+    }
+}
+
 impl PartialEq<Mime> for ContentType {
     fn eq(&self, other: &Mime) -> bool {
         &self.media_type == other

src/headers/header.rs

@@ -0,0 +1,41 @@
+use crate::headers::{HeaderName, HeaderValue, Headers};
+
+/// A trait representing a [`HeaderName`] and [`HeaderValue`] pair.
+pub trait Header {
+    /// Access the header's name.
+    fn header_name(&self) -> HeaderName;
+
+    /// Access the header's value.
+    fn header_value(&self) -> HeaderValue;
+
+    /// Insert the header name and header value into something that looks like a
+    /// [`Headers`] map.
+    fn apply_header<H: AsMut<Headers>>(&self, mut headers: H) {
+        let name = self.header_name();
+        let value = self.header_value();
+        headers.as_mut().insert(name, value);
+    }
+}
+
+impl<'a, 'b> Header for (&'a str, &'b str) {
+    fn header_name(&self) -> HeaderName {
+        HeaderName::from(self.0)
+    }
+
+    fn header_value(&self) -> HeaderValue {
+        HeaderValue::from_bytes(self.1.to_owned().into_bytes())
+            .expect("String slice should be valid ASCII")
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn header_from_strings() {
+        let strings = ("Content-Length", "12");
+        assert_eq!(strings.header_name(), "Content-Length");
+        assert_eq!(strings.header_value(), "12");
+    }
+}

src/headers/mod.rs

@@ -1,6 +1,7 @@
 //! HTTP headers.
 
 mod constants;
+mod header;
 mod header_name;
 mod header_value;
 mod header_values;
@@ -14,6 +15,7 @@ mod to_header_values;
 mod values;
 
 pub use constants::*;
+pub use header::Header;
 pub use header_name::HeaderName;
 pub use header_value::HeaderValue;
 pub use header_values::HeaderValues;