Emit const assertions for every vector element type
diff --git a/src/cxx_vector.rs b/src/cxx_vector.rs
index d9e8892..8294044 100644
--- a/src/cxx_vector.rs
+++ b/src/cxx_vector.rs
@@ -136,6 +136,8 @@
 
 macro_rules! impl_vector_element_for_primitive {
     ($ty:ident) => {
+        const_assert_eq!(1, mem::align_of::<CxxVector<$ty>>());
+
         unsafe impl VectorElement for $ty {
             const __NAME: &'static dyn Display = &stringify!($ty);
             fn __vector_size(v: &CxxVector<$ty>) -> usize {
@@ -230,5 +232,3 @@
 impl_vector_element_for_primitive!(isize);
 impl_vector_element_for_primitive!(f32);
 impl_vector_element_for_primitive!(f64);
-
-const_assert_eq!(1, mem::align_of::<CxxVector<usize>>());