diff --git a/src/vector.rs b/src/vector.rs
index 0a2214f..f52232a 100644
--- a/src/vector.rs
+++ b/src/vector.rs
@@ -346,6 +346,11 @@ macro_rules! impl_vector_default {
         impl<S: Copy> Array for $VectorN<S> {
             type Element = S;
 
+            #[inline]
+            fn len() -> usize {
+                $n
+            }
+
             #[inline]
             fn from_value(scalar: S) -> $VectorN<S> {
                 $VectorN { $($field: scalar),+ }