Moved checked trait impls out of std::num

This follows the same pattern as the other numeric trait impls, and reduces the clutter in std::num.

1 files changed, 35 insertions, 0 deletions

diff --git a/src/libstd/num/u32.rs b/src/libstd/num/u32.rs
index f87fa7fcd42..4dbd543da7b 100644
--- a/src/libstd/num/u32.rs
+++ b/src/libstd/num/u32.rs
@@ -10,5 +10,40 @@
 
 //! Operations and constants for `u32`
 
+use num::{CheckedAdd, CheckedSub, CheckedMul};
+use option::{Option, Some, None};
+use unstable::intrinsics;
+
 pub use self::generated::*;
+
 uint_module!(u32, i32, 32)
+
+impl CheckedAdd for u32 {
+    #[inline]
+    fn checked_add(&self, v: &u32) -> Option<u32> {
+        unsafe {
+            let (x, y) = intrinsics::u32_add_with_overflow(*self, *v);
+            if y { None } else { Some(x) }
+        }
+    }
+}
+
+impl CheckedSub for u32 {
+    #[inline]
+    fn checked_sub(&self, v: &u32) -> Option<u32> {
+        unsafe {
+            let (x, y) = intrinsics::u32_sub_with_overflow(*self, *v);
+            if y { None } else { Some(x) }
+        }
+    }
+}
+
+impl CheckedMul for u32 {
+    #[inline]
+    fn checked_mul(&self, v: &u32) -> Option<u32> {
+        unsafe {
+            let (x, y) = intrinsics::u32_mul_with_overflow(*self, *v);
+            if y { None } else { Some(x) }
+        }
+    }
+}