diff --git a/src/funs/common.rs b/src/funs/common.rs
index 4cc229f..8237fcf 100644
--- a/src/funs/common.rs
+++ b/src/funs/common.rs
@@ -7,89 +7,89 @@ use vector::*;
 /**
  * Common Functions for all numeric types
  */
-pub trait Numeric {
+pub trait Extent {
     pure fn min(y: &self) -> self;
     pure fn max(y: &self) -> self;
     pure fn clamp(minv: &self, maxv: &self) -> self;
 }
 
-#[inline(always)] pub pure fn min<T:Numeric>(x: &T, y: &T) -> T { x.min(y) }
-#[inline(always)] pub pure fn max<T:Numeric>(x: &T, y: &T) -> T { x.max(y) }
-#[inline(always)] pub pure fn clamp<T:Numeric>(x: &T, minv: &T, maxv: &T) -> T { x.clamp(minv, maxv) }
+#[inline(always)] pub pure fn min<T:Extent>(x: &T, y: &T) -> T { x.min(y) }
+#[inline(always)] pub pure fn max<T:Extent>(x: &T, y: &T) -> T { x.max(y) }
+#[inline(always)] pub pure fn clamp<T:Extent>(x: &T, minv: &T, maxv: &T) -> T { x.clamp(minv, maxv) }
 
-pub impl u8: Numeric {
+pub impl u8: Extent {
     #[inline(always)] pure fn min(y: &u8) -> u8 { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &u8) -> u8 { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &u8, maxv: &u8) -> u8 { min(&max(&self, minv), maxv) }
 }
 
-pub impl u16: Numeric {
+pub impl u16: Extent {
     #[inline(always)] pure fn min(y: &u16) -> u16 { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &u16) -> u16 { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &u16, maxv: &u16) -> u16 { min(&max(&self, minv), maxv) }
 }
 
-pub impl u32: Numeric {
+pub impl u32: Extent {
     #[inline(always)] pure fn min(y: &u32) -> u32 { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &u32) -> u32 { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &u32, maxv: &u32) -> u32 { min(&max(&self, minv), maxv) }
 }
 
-pub impl u64: Numeric {
+pub impl u64: Extent {
     #[inline(always)] pure fn min(y: &u64) -> u64 { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &u64) -> u64 { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &u64, maxv: &u64) -> u64 { min(&max(&self, minv), maxv) }
 }
 
-pub impl uint: Numeric {
+pub impl uint: Extent {
     #[inline(always)] pure fn min(y: &uint) -> uint { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &uint) -> uint { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &uint, maxv: &uint) -> uint { min(&max(&self, minv), maxv) }
 }
 
-pub impl i8: Numeric {
+pub impl i8: Extent {
     #[inline(always)] pure fn min(y: &i8) -> i8 { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &i8) -> i8 { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &i8, maxv: &i8) -> i8 { min(&max(&self, minv), maxv) }
 }
 
-pub impl i16: Numeric {
+pub impl i16: Extent {
     #[inline(always)] pure fn min(y: &i16) -> i16 { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &i16) -> i16 { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &i16, maxv: &i16) -> i16 { min(&max(&self, minv), maxv) }
 }
 
-pub impl i32: Numeric {
+pub impl i32: Extent {
     #[inline(always)] pure fn min(y: &i32) -> i32 { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &i32) -> i32 { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &i32, maxv: &i32) -> i32 { min(&max(&self, minv), maxv) }
 }
 
-pub impl i64: Numeric {
+pub impl i64: Extent {
     #[inline(always)] pure fn min(y: &i64) -> i64 { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &i64) -> i64 { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &i64, maxv: &i64) -> i64 { min(&max(&self, minv), maxv) }
 }
 
-pub impl int: Numeric {
+pub impl int: Extent {
     #[inline(always)] pure fn min(y: &int) -> int { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &int) -> int { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &int, maxv: &int) -> int { min(&max(&self, minv), maxv) }
 }
 
-pub impl f32: Numeric {
+pub impl f32: Extent {
     #[inline(always)] pure fn min(y: &f32) -> f32 { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &f32) -> f32 { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &f32, maxv: &f32) -> f32 { min(&max(&self, minv), maxv) }
 }
 
-pub impl f64: Numeric {
+pub impl f64: Extent {
     #[inline(always)] pure fn min(y: &f64) -> f64 { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &f64) -> f64 { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &f64, maxv: &f64) -> f64 { min(&max(&self, minv), maxv) }
 }
 
-pub impl float: Numeric {
+pub impl float: Extent {
     #[inline(always)] pure fn min(y: &float) -> float { if self < *y { self } else { *y } }
     #[inline(always)] pure fn max(y: &float) -> float { if self > *y { self } else { *y } }
     #[inline(always)] pure fn clamp(minv: &float, maxv: &float) -> float { min(&max(&self, minv), maxv) }