diff --git a/src/cgmath/array.rs b/src/cgmath/array.rs
index 5494fa5..5ce96d3 100644
--- a/src/cgmath/array.rs
+++ b/src/cgmath/array.rs
@@ -50,6 +50,8 @@ pub trait Array
              V: Clone, SliceV, VV: Array<V, SliceV>>(&self, other: &UU, f: &fn(&T, &U) -> V) -> VV {
         Array::build(|i| f(self.i(i), other.i(i)))
     }
+
+    fn zip(&self, f: &fn(&T, &T) -> T) -> T;
 }
 
 macro_rules! array(
@@ -94,17 +96,27 @@ macro_rules! array(
             fn mut_iter<'a>(&'a mut self) -> ::std::vec::VecMutIterator<'a, $T> {
                 self.as_mut_slice().mut_iter()
             }
+
+            #[inline]
+            fn zip(&self, f: &fn(&$T, &$T) -> $T) -> $T {
+                gen_zip!($_n)
+            }
         }
     )
 )
 
 macro_rules! gen_builder(
-    (_1) => ([builder(0)]);
     (_2) => ([builder(0), builder(1)]);
     (_3) => ([builder(0), builder(1), builder(2)]);
     (_4) => ([builder(0), builder(1), builder(2), builder(3)]);
 )
 
+macro_rules! gen_zip(
+    (_2) => (f(self.i(0), self.i(1)));
+    (_3) => (f(&f(self.i(0), self.i(1)), self.i(2)));
+    (_4) => (f(&f(&f(self.i(0), self.i(1)), self.i(2)), self.i(3)));
+)
+
 macro_rules! approx_eq(
     (impl<$S:ident> $Self:ty) => (
         impl<$S: Clone + ApproxEq<$S>> ApproxEq<$S> for $Self {
diff --git a/src/cgmath/vector.rs b/src/cgmath/vector.rs
index 2f10772..8a436e4 100644
--- a/src/cgmath/vector.rs
+++ b/src/cgmath/vector.rs
@@ -130,10 +130,10 @@ pub trait Vector
     #[inline] fn rem_self_v(&mut self, other: &Self);
 
     /// The sum of each component of the vector.
-    #[inline] fn comp_add(&self) -> S;
+    #[inline] fn comp_add(&self) -> S { self.zip(|a, b| a.add(b)) }
 
     /// The product of each component of the vector.
-    #[inline] fn comp_mul(&self) -> S;
+    #[inline] fn comp_mul(&self) -> S { self.zip(|a, b| a.mul(b)) }
 
     /// Vector dot product.
     #[inline] fn dot(&self, other: &Self) -> S { self.mul_v(other).comp_add() }
@@ -181,12 +181,6 @@ macro_rules! vector(
             #[inline] fn mul_self_v(&mut self, other: &$Self<$S>) { self.$x = self.$x.mul(&other.$x); $(self.$xs = self.$xs.mul(&other.$xs);)+ }
             #[inline] fn div_self_v(&mut self, other: &$Self<$S>) { self.$x = self.$x.div(&other.$x); $(self.$xs = self.$xs.div(&other.$xs);)+ }
             #[inline] fn rem_self_v(&mut self, other: &$Self<$S>) { self.$x = self.$x.rem(&other.$x); $(self.$xs = self.$xs.rem(&other.$xs);)+ }
-
-            /// The sum of each component of the vector.
-            #[inline] fn comp_add(&self) -> S { self.$x $(.add(&self.$xs))+ }
-
-            /// The product of each component of the vector.
-            #[inline] fn comp_mul(&self) -> S { self.$x $(.mul(&self.$xs))+ }
         }
     )
 )