support macaddr::MacAddr6 with Pg

diesel/Cargo.toml

@@ -34,6 +34,7 @@ bitflags = { version = "2.0.0", optional = true }
 r2d2 = { version = ">= 0.8.2, < 0.9.0", optional = true }
 itoa = { version = "1.0.0", optional = true }
 time = { version = "0.3.9", optional = true, features = ["macros"] }
+macaddr = { version = "1.0.1", optional = true }
 
 [dependencies.diesel_derives]
 version = "~2.0.0"
@@ -47,7 +48,7 @@ quickcheck = "1.0.3"
 
 [features]
 default = ["with-deprecated", "32-column-tables"]
-extras = ["chrono", "time", "serde_json", "uuid", "network-address", "numeric", "r2d2"]
+extras = ["chrono", "time", "serde_json", "uuid", "network-address", "numeric", "r2d2", "macaddr"]
 unstable = ["diesel_derives/nightly"]
 large-tables = ["32-column-tables"]
 huge-tables = ["64-column-tables"]

diesel/src/pg/types/mac_addr.rs

@@ -37,6 +37,21 @@ impl ToSql<MacAddr, Pg> for [u8; 6] {
     }
 }
 
+#[cfg(all(feature = "macaddr", feature = "postgres_backend"))]
+impl FromSql<MacAddr, Pg> for macaddr::MacAddr6 {
+    fn from_sql(value: PgValue<'_>) -> deserialize::Result<Self> {
+        <[u8; 6] as FromSql<MacAddr, Pg>>::from_sql(value).map(Into::into)
+    }
+}
+
+#[cfg(all(feature = "macaddr", feature = "postgres_backend"))]
+impl ToSql<MacAddr, Pg> for macaddr::MacAddr6 {
+    fn to_sql<'b>(&'b self, out: &mut Output<'b, '_, Pg>) -> serialize::Result {
+        let array_value = self.into_array();
+        <[u8; 6] as ToSql<MacAddr, Pg>>::to_sql(&array_value, &mut out.reborrow())
+    }
+}
+
 #[test]
 fn macaddr_roundtrip() {
     use crate::query_builder::bind_collector::ByteWrapper;
@@ -45,6 +60,16 @@ fn macaddr_roundtrip() {
     let mut bytes = Output::test(ByteWrapper(&mut buffer));
     let input_address = [0x52, 0x54, 0x00, 0xfb, 0xc6, 0x16];
     ToSql::<MacAddr, Pg>::to_sql(&input_address, &mut bytes).unwrap();
+
     let output_address: [u8; 6] = FromSql::from_sql(PgValue::for_test(&buffer)).unwrap();
     assert_eq!(input_address, output_address);
+
+    #[cfg(feature = "macaddr")]
+    {
+        use macaddr::MacAddr6;
+
+        let input_address: MacAddr6 = input_address.into();
+        let output_address: MacAddr6 = FromSql::from_sql(PgValue::for_test(&buffer)).unwrap();
+        assert_eq!(input_address, output_address);
+    }
 }

diesel_tests/tests/types.rs

@@ -1048,6 +1048,12 @@ fn pg_macaddress_from_sql() {
         expected_value,
         query_single_value::<MacAddr, [u8; 6]>(query)
     );
+
+    #[cfg(feature = "macaddr")]
+    assert_eq!(
+        expected_value,
+        query_single_value::<MacAddr, macaddr::MacAddr6>(query)
+    );
 }
 
 #[test]
@@ -1059,6 +1065,14 @@ fn pg_macaddress_to_sql_macaddress() {
         expected_value,
         value
     ));
+
+    #[cfg(feature = "macaddr")]
+    {
+        assert!(query_to_sql_equality::<MacAddr, macaddr::MacAddr6>(
+            expected_value,
+            macaddr::MacAddr6::new(0x08, 0x00, 0x2b, 0x01, 0x02, 0x03)
+        ));
+    }
 }
 
 #[test]