Add `deriving(Copy)` for `Copy`able structs/enums/

src/bigint.rs

@@ -857,7 +857,7 @@ fn get_radix_base(radix: uint) -> (DoubleBigDigit, uint) {
 }
 
 /// A Sign is a `BigInt`'s composing element.
-#[deriving(PartialEq, PartialOrd, Eq, Ord, Clone, Show, Encodable, Decodable)]
+#[deriving(PartialEq, PartialOrd, Eq, Ord, Copy, Clone, Show, Encodable, Decodable)]
 pub enum Sign { Minus, NoSign, Plus }
 
 impl Neg<Sign> for Sign {

src/complex.rs

@@ -21,7 +21,7 @@ use {Zero, One, Num};
 // probably doesn't map to C's _Complex correctly.
 
 /// A complex number in Cartesian form.
-#[deriving(PartialEq, Clone, Hash, Encodable, Decodable)]
+#[deriving(PartialEq, Copy, Clone, Hash, Encodable, Decodable)]
 pub struct Complex<T> {
     /// Real portion of the complex number
     pub re: T,

src/rational.rs

@@ -22,7 +22,7 @@ use bigint::{BigInt, BigUint, Sign};
 use {Num, Signed, Zero, One};
 
 /// Represents the ratio between 2 numbers.
-#[deriving(Clone, Hash, Encodable, Decodable)]
+#[deriving(Copy, Clone, Hash, Encodable, Decodable)]
 #[allow(missing_docs)]
 pub struct Ratio<T> {
     numer: T,