libstd: impl Num for BigUint/BigInt

src/libstd/num/bigint.rs

@@ -144,6 +144,8 @@ fn from_str(s: &str) -> Option<BigUint> {
     }
 }
 
+impl Num for BigUint {}
+
 impl Shl<uint, BigUint> for BigUint {
     #[inline(always)]
     fn shl(&self, rhs: &uint) -> BigUint {
@@ -788,6 +790,8 @@ fn from_str(s: &str) -> Option<BigInt> {
     }
 }
 
+impl Num for BigInt {}
+
 impl Shl<uint, BigInt> for BigInt {
     #[inline(always)]
     fn shl(&self, rhs: &uint) -> BigInt {