Added Round trait to core

1 files changed, 33 insertions, 0 deletions

diff --git a/src/libcore/num/float.rs b/src/libcore/num/float.rs
index b90edec4d96..1d1be6df87a 100644
--- a/src/libcore/num/float.rs
+++ b/src/libcore/num/float.rs
@@ -488,6 +488,39 @@ impl float: num::One {
     static pure fn one() -> float { 1.0 }
 }
 
+impl float: num::Round {
+    #[inline(always)]
+    pure fn round(&self, mode: num::RoundMode) -> float {
+        match mode {
+            num::RoundDown
+                => f64::floor(*self as f64) as float,
+            num::RoundUp
+                => f64::ceil(*self as f64) as float,
+            num::RoundToZero   if is_negative(*self)
+                => f64::ceil(*self as f64) as float,
+            num::RoundToZero
+                => f64::floor(*self as f64) as float,
+            num::RoundFromZero if is_negative(*self)
+                => f64::floor(*self as f64) as float,
+            num::RoundFromZero
+                => f64::ceil(*self as f64) as float
+        }
+    }
+
+    #[inline(always)]
+    pure fn floor(&self) -> float { f64::floor(*self as f64) as float}
+    #[inline(always)]
+    pure fn ceil(&self) -> float { f64::ceil(*self as f64) as float}
+    #[inline(always)]
+    pure fn fract(&self) -> float {
+        if is_negative(*self) {
+            (*self) - (f64::ceil(*self as f64) as float)
+        } else {
+            (*self) - (f64::floor(*self as f64) as float)
+        }
+    }
+}
+
 #[test]
 pub fn test_from_str() {
    assert from_str(~"3") == Some(3.);