diff --git a/src/vec.rs b/src/vec.rs
index d591a3a3..a6bde482 100644
--- a/src/vec.rs
+++ b/src/vec.rs
@@ -145,6 +145,60 @@ translate_impl!(Vec3)
 rotate_impl!(Vec3)
 transform_impl!(Vec3)
 
+
+/// Vector of dimension 3 with an extra component for padding.
+#[deriving(Eq, Encodable, Decodable, Clone, DeepClone, IterBytes, Rand, Zero, ToStr)]
+pub struct PVec3<N> {
+    /// First component of the vector.
+    x: N,
+    /// Second component of the vector.
+    y: N,
+    /// Third component of the vector.
+    z: N,
+    // Unused component, for padding
+    priv _unused: N
+}
+
+impl<N: Clone> PVec3<N> {
+    /// Creates a new 3d vector.
+    pub fn new(x: N, y: N, z: N) -> PVec3<N> {
+        PVec3 { x: x.clone(), y: y, z: z, _unused: x }
+    }
+}
+
+ord_impl!(PVec3, x, y, z)
+orderable_impl!(PVec3, x, y, z)
+vec_axis_impl!(PVec3, x, y, z)
+vec_cast_impl!(PVec3, x, y, z)
+indexable_impl!(PVec3, 3)
+new_repeat_impl!(PVec3, val, x, y, z, _unused)
+dim_impl!(PVec3, 3)
+// (specialized) basis_impl!(PVec3, 1)
+add_impl!(PVec3, x, y, z)
+sub_impl!(PVec3, x, y, z)
+neg_impl!(PVec3, x, y, z)
+dot_impl!(PVec3, x, y, z)
+scalar_mul_impl!(PVec3, x, y, z)
+scalar_div_impl!(PVec3, x, y, z)
+scalar_add_impl!(PVec3, x, y, z)
+scalar_sub_impl!(PVec3, x, y, z)
+translation_impl!(PVec3)
+norm_impl!(PVec3)
+approx_eq_impl!(PVec3, x, y, z)
+round_impl!(PVec3, x, y, z)
+one_impl!(PVec3)
+from_iterator_impl!(PVec3, iterator, iterator, iterator)
+bounded_impl!(PVec3)
+iterable_impl!(PVec3, 3)
+iterable_mut_impl!(PVec3, 3)
+to_homogeneous_impl!(PVec3, Vec4, w, x, y, z)
+from_homogeneous_impl!(PVec3, Vec4, w, x, y, z)
+translate_impl!(PVec3)
+rotate_impl!(PVec3)
+transform_impl!(PVec3)
+
+
+
 /// Vector of dimension 4.
 #[deriving(Eq, Encodable, Decodable, Clone, DeepClone, IterBytes, Rand, Zero, ToStr)]
 pub struct Vec4<N> {
diff --git a/src/vec_macros.rs b/src/vec_macros.rs
index ba462ebb..c79a5b4d 100644
--- a/src/vec_macros.rs
+++ b/src/vec_macros.rs
@@ -43,7 +43,7 @@ macro_rules! ord_impl(
 
 macro_rules! orderable_impl(
     ($t: ident, $comp0: ident $(,$compN: ident)*) => (
-        impl<N: Orderable> Orderable for $t<N> {
+        impl<N: Clone + Orderable> Orderable for $t<N> {
             #[inline]
             fn max(&self, other: &$t<N>) -> $t<N> {
                 $t::new(self.$comp0.max(&other.$comp0) $(, self.$compN.max(&other.$compN))*)
@@ -93,7 +93,7 @@ macro_rules! vec_axis_impl(
 
 macro_rules! vec_cast_impl(
     ($t: ident, $comp0: ident $(,$compN: ident)*) => (
-        impl<Nin: NumCast + Clone, Nout: NumCast> VecCast<$t<Nout>> for $t<Nin> {
+        impl<Nin: NumCast + Clone, Nout: Clone + NumCast> VecCast<$t<Nout>> for $t<Nin> {
             #[inline]
             fn from(v: $t<Nin>) -> $t<Nout> {
                 $t::new(NumCast::from(v.$comp0.clone()) $(, NumCast::from(v.$compN.clone()))*)
@@ -233,7 +233,7 @@ macro_rules! basis_impl(
 
 macro_rules! add_impl(
     ($t: ident, $comp0: ident $(,$compN: ident)*) => (
-        impl<N: Add<N, N>> Add<$t<N>, $t<N>> for $t<N> {
+        impl<N: Clone + Add<N, N>> Add<$t<N>, $t<N>> for $t<N> {
             #[inline]
             fn add(&self, other: &$t<N>) -> $t<N> {
                 $t::new(self.$comp0 + other.$comp0 $(, self.$compN + other.$compN)*)
@@ -244,7 +244,7 @@ macro_rules! add_impl(
 
 macro_rules! sub_impl(
     ($t: ident, $comp0: ident $(,$compN: ident)*) => (
-        impl<N: Sub<N, N>> Sub<$t<N>, $t<N>> for $t<N> {
+        impl<N: Clone + Sub<N, N>> Sub<$t<N>, $t<N>> for $t<N> {
             #[inline]
             fn sub(&self, other: &$t<N>) -> $t<N> {
                 $t::new(self.$comp0 - other.$comp0 $(, self.$compN - other.$compN)*)
@@ -255,7 +255,7 @@ macro_rules! sub_impl(
 
 macro_rules! neg_impl(
     ($t: ident, $comp0: ident $(,$compN: ident)*) => (
-        impl<N: Neg<N>> Neg<$t<N>> for $t<N> {
+        impl<N: Clone + Neg<N>> Neg<$t<N>> for $t<N> {
             #[inline]
             fn neg(&self) -> $t<N> {
                 $t::new(-self.$comp0 $(, -self.$compN )*)
@@ -282,7 +282,7 @@ macro_rules! dot_impl(
 
 macro_rules! scalar_mul_impl(
     ($t: ident, $comp0: ident $(,$compN: ident)*) => (
-        impl<N: Mul<N, N>> Mul<N, $t<N>> for $t<N> {
+        impl<N: Clone + Mul<N, N>> Mul<N, $t<N>> for $t<N> {
             #[inline]
             fn mul(&self, s: &N) -> $t<N> {
                 $t::new(self.$comp0 * *s $(, self.$compN * *s)*)
@@ -293,7 +293,7 @@ macro_rules! scalar_mul_impl(
 
 macro_rules! scalar_div_impl(
     ($t: ident, $comp0: ident $(,$compN: ident)*) => (
-        impl<N: Div<N, N>> Div<N, $t<N>> for $t<N> {
+        impl<N: Clone + Div<N, N>> Div<N, $t<N>> for $t<N> {
             #[inline]
             fn div(&self, s: &N) -> $t<N> {
                 $t::new(self.$comp0 / *s $(, self.$compN / *s)*)
@@ -304,7 +304,7 @@ macro_rules! scalar_div_impl(
 
 macro_rules! scalar_add_impl(
     ($t: ident, $comp0: ident $(,$compN: ident)*) => (
-        impl<N: Add<N, N>> ScalarAdd<N> for $t<N> {
+        impl<N: Clone + Add<N, N>> ScalarAdd<N> for $t<N> {
             #[inline]
             fn scalar_add(&self, s: &N) -> $t<N> {
                 $t::new(self.$comp0 + *s $(, self.$compN + *s)*)
@@ -321,7 +321,7 @@ macro_rules! scalar_add_impl(
 
 macro_rules! scalar_sub_impl(
     ($t: ident, $comp0: ident $(,$compN: ident)*) => (
-        impl<N: Sub<N, N>> ScalarSub<N> for $t<N> {
+        impl<N: Clone + Sub<N, N>> ScalarSub<N> for $t<N> {
             #[inline]
             fn scalar_sub(&self, s: &N) -> $t<N> {
                 $t::new(self.$comp0 - *s $(, self.$compN - *s)*)
@@ -398,7 +398,7 @@ macro_rules! norm_impl(
 
 macro_rules! round_impl(
     ($t: ident, $comp0: ident $(,$compN: ident)*) => (
-        impl<N: Round> Round for $t<N> {
+        impl<N: Clone + Round> Round for $t<N> {
             fn floor(&self) -> $t<N> {
                 $t::new(self.$comp0.floor() $(, self.$compN.floor())*)
             }
@@ -457,7 +457,7 @@ macro_rules! one_impl(
 
 macro_rules! from_iterator_impl(
     ($t: ident, $param0: ident $(, $paramN: ident)*) => (
-        impl<N> FromIterator<N> for $t<N> {
+        impl<N: Clone> FromIterator<N> for $t<N> {
             #[inline]
             fn from_iterator<I: Iterator<N>>($param0: &mut I) -> $t<N> {
                 $t::new($param0.next().unwrap() $(, $paramN.next().unwrap())*)
@@ -516,7 +516,7 @@ macro_rules! from_homogeneous_impl(
 
 macro_rules! translate_impl(
     ($t: ident) => (
-        impl<N: Add<N, N> + Sub<N, N>> Translate<$t<N>> for $t<N> {
+        impl<N: Clone + Add<N, N> + Sub<N, N>> Translate<$t<N>> for $t<N> {
             fn translate(&self, other: &$t<N>) -> $t<N> {
                 *other + *self
             }
@@ -544,7 +544,7 @@ macro_rules! rotate_impl(
 
 macro_rules! transform_impl(
     ($t: ident) => (
-        impl<N: Add<N, N> + Sub<N, N>> Transform<$t<N>> for $t<N> {
+        impl<N: Clone + Add<N, N> + Sub<N, N>> Transform<$t<N>> for $t<N> {
             fn transform(&self, other: &$t<N>) -> $t<N> {
                 self.translate(other)
             }
diff --git a/src/vec_spec.rs b/src/vec_spec.rs
index e2995857..043d2c3a 100644
--- a/src/vec_spec.rs
+++ b/src/vec_spec.rs
@@ -185,7 +185,7 @@ static SAMPLES_3_F64: [Vec3<f64>, ..42] = [
     Vec3 { x: 0.162456 , y: 0.499995 , z: 0.850654 }
 ];
 
-impl<N: NumCast> UniformSphereSample for Vec2<N> {
+impl<N: NumCast + Clone> UniformSphereSample for Vec2<N> {
     #[inline(always)]
     fn sample(f: &fn(Vec2<N>)) {
          for sample in SAMPLES_2_F64.iter() {
@@ -194,7 +194,7 @@ impl<N: NumCast> UniformSphereSample for Vec2<N> {
      }
 }
 
-impl<N: NumCast> UniformSphereSample for Vec3<N> {
+impl<N: NumCast + Clone> UniformSphereSample for Vec3<N> {
     #[inline(always)]
     fn sample(f: &fn(Vec3<N>)) {
         for sample in SAMPLES_3_F64.iter() {