add tokio-postgres behind feature flag

Cargo.toml

@@ -11,6 +11,7 @@ keywords = ["error", "result"]
 askama = { version = "0.12", optional = true }
 log = { version = "0.4", features = ["std"], optional = true }
 serde_json = { version = "1.0", optional = true }
+tokio-postgres = { version = "0.7", optional = true}
 ureq = { version = "2.6", optional = true }
 
 [features]

src/lib.rs

@@ -90,6 +90,13 @@ impl From<serde_json::Error> for Rear {
 	}
 }
 
+#[cfg(feature = "tokio_postgres")]
+impl From<tokio_postgres::Error> for Rear {
+	fn from(error: tokio_postgres::Error) -> Self {
+		Self { message: error.to_string(), error: error.into() }
+	}
+}
+
 #[cfg(feature = "ureq")]
 impl From<ureq::Error> for Rear {
 	fn from(error: ureq::Error) -> Self {