Add optional serde support; Remove Clone from most error types;

Cargo.toml

@@ -14,3 +14,8 @@ x509-parser = "0.15.0"
 version = "0.21.1"
 features = [ "dangerous_configuration" ]
 
+[dependencies.serde]
+version = "1.0"
+features = ["derive"]
+optional = true
+

src/fingerprint/error.rs

@@ -1,6 +1,6 @@
 use {std::fmt, x509_parser::prelude::X509Error};
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Debug)]
 /// Errors which can occur when fingerprinting a certificate
 pub enum Error {
     Fmt,

src/host/error.rs

@@ -1,6 +1,6 @@
 use std::fmt;
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Debug, PartialEq)]
 /// Errors which can occur when parsing a host from a string
 pub enum Error {
     MissingSeparator,

src/host/mod.rs

@@ -2,7 +2,11 @@ use std::{fmt, str::FromStr};
 mod error;
 pub use error::Error;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 #[derive(Clone, Debug, Default, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 /// Represents the fully qualified domain name for this host
 pub struct Host {
     pub subdomain: Option<String>,

src/prelude.rs

@@ -5,5 +5,8 @@ pub use super::{
     request::{Error as ParseRequestError, Request},
     response::{Error as ParseResponseError, Response},
     sender::{CertificateStore, Error as SenderError, Sender, Verifier},
-    status::{Error as ParseStatusError, Status, Redirect, TemporaryFailure, PermanentFailure, AuthenticationFailure},
+    status::{
+        AuthenticationFailure, Error as ParseStatusError, PermanentFailure, Redirect, Status,
+        TemporaryFailure,
+    },
 };

src/request/error.rs

@@ -1,6 +1,6 @@
 use {crate::prelude::ParseHostError, std::fmt};
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Debug, PartialEq)]
 /// Errors which can occur when parsing a request
 pub enum Error {
     MissingSeparator,

src/request/mod.rs

@@ -1,10 +1,14 @@
 use crate::prelude::Host;
 use std::{fmt, str::FromStr};
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 mod error;
 pub use error::Error;
 
 #[derive(Clone, Debug, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 /// The full request as sent by the `Sender` and received by the `Receiver`
 pub struct Request {
     /// The username of the sender

src/response/error.rs

@@ -3,7 +3,7 @@ use {
     std::{fmt, num::ParseIntError},
 };
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Debug, PartialEq)]
 /// Errors which can occur when parsing the response sent by the receving server
 /// back to the sender
 pub enum Error {

src/response/mod.rs

@@ -4,7 +4,11 @@ use std::{fmt, str::FromStr};
 mod error;
 pub use error::Error;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 #[derive(Clone, Debug, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 /// Sent from the receiving server back to the sending server
 pub struct Response {
     pub status: Status,

src/status/error.rs

@@ -1,6 +1,6 @@
 use std::fmt;
 
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug)]
 /// The receiving server sent an unrecognized or invalid status code
 pub struct Error;
 

src/status/mod.rs

@@ -1,7 +1,11 @@
 mod error;
 pub use error::Error;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 #[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[repr(u8)]
 /// Status codes sent back to the sender representing how a receiving server has
 /// processed a message.
@@ -54,6 +58,7 @@ impl TryFrom<u8> for Status {
 }
 
 #[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 /// Status codes representing that a redirect is required
 pub enum Redirect {
     /// The mailbox has moved to a different address, and this message
@@ -79,6 +84,7 @@ impl TryFrom<u8> for Redirect {
 }
 
 #[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 /// Status codes representing that a temporary failure has occurred. The sending server should
 /// retry sending the message.
 pub enum TemporaryFailure {
@@ -117,6 +123,7 @@ impl TryFrom<u8> for TemporaryFailure {
 }
 
 #[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 /// Status codes representing that a permanent failure has occurred and the sending
 /// server should not resend the message.
 pub enum PermanentFailure {
@@ -152,6 +159,7 @@ impl TryFrom<u8> for PermanentFailure {
 }
 
 #[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 /// Status codes representing an authentication failure
 pub enum AuthenticationFailure {
     /// This mailserver doesn't accept anonymous mail, and you need to repeat your