implement Incrementable for native types

uint/src/uint.rs

@@ -127,6 +127,22 @@ impl From<FromHexError> for FromStrRadixErr {
 	}
 }
 
+macro_rules! impl_incrementable {
+	($($type:ty),+) => {
+		$(
+			impl Incrementable for $type {
+				fn increment(&self) -> Option<Self> {
+					self.checked_add(1)
+				}
+
+				fn initial_value() -> Option<Self> {
+					Some(0)
+				}
+			}
+		)+
+	};
+}
+
 /// A trait representing an incrementable type.
 ///
 /// The `increment` and `initial_value` functions are fallible.
@@ -146,6 +162,10 @@ pub trait Incrementable
 	fn initial_value() -> Option<Self>;
 }
 
+impl_incrementable!(u8, u16, u32, u64, u128, i8, i16, i32, i64, i128);
+
+
+
 /// Conversion from decimal string error
 #[derive(Debug, PartialEq, Eq)]
 pub enum FromDecStrErr {

uint/tests/uint_tests.rs

@@ -1194,6 +1194,17 @@ fn bit_assign() {
 
 #[test]
 fn increment() {
+	macro_rules! test_incrementable {
+		($($type:ident),+) => {
+			$(
+				assert_eq!($type::from(0 as $type).increment(), Some(1 as $type));
+				assert_eq!($type::max_value().increment(), None);
+				assert_eq!($type::initial_value(), Some(0 as $type));
+			)+
+		};
+	}
+	test_incrementable!(u8, u16, u32, u64, u128, i8, i16, i32, i64, i128);
+
 	assert_eq!(U256::from(0).increment(), Some(1.into()));
 	assert_eq!(U256::max_value().increment(), None);
 	assert_eq!(U256::initial_value(), Some(0.into()));