core: Formulate all unsigned max_values as 0 - 1 for consistency

Author: brson

src/libcore/u32.rs

@@ -16,7 +16,7 @@ Const: max_value
 
 Return the maximal value for a u32
 */
-const max_value: u32 = 0xffff_ffffu32;
+const max_value: u32 = 0u32 - 1u32;
 
 pure fn min(x: u32, y: u32) -> u32 { if x < y { x } else { y } }
 pure fn max(x: u32, y: u32) -> u32 { if x > y { x } else { y } }

src/libcore/u64.rs

@@ -16,7 +16,7 @@ Const: max_value
 
 Return the maximal value for a u64
 */
-const max_value: u64 = 18446744073709551615u64;
+const max_value: u64 = 0u64 - 1u64;
 
 pure fn min(x: u64, y: u64) -> u64 { if x < y { x } else { y } }
 pure fn max(x: u64, y: u64) -> u64 { if x > y { x } else { y } }

src/libcore/u8.rs

@@ -16,7 +16,7 @@ Const: max_value
 
 The maximum value of a u8.
 */
-const max_value: u8 = 255u8;
+const max_value: u8 = 0u8 - 1u8;
 
 /* Function: add */
 pure fn add(x: u8, y: u8) -> u8 { ret x + y; }