diff --git a/crates/fayalite/src/array.rs b/crates/fayalite/src/array.rs
index a3aea79..f617f91 100644
--- a/crates/fayalite/src/array.rs
+++ b/crates/fayalite/src/array.rs
@@ -85,7 +85,7 @@ impl<T: Type, Len: Size> ArrayType<T, Len> {
     }
 }
 
-impl<T: Type, Len: KnownSize> ArrayType<T, Len> {
+impl<T: Type, Len: KnownSize + Size<SizeType = Len>> ArrayType<T, Len> {
     pub fn new_static(element: T) -> Self {
         Self::new(element, Len::SizeType::default())
     }
diff --git a/crates/fayalite/src/int.rs b/crates/fayalite/src/int.rs
index dd631d0..03b2c88 100644
--- a/crates/fayalite/src/int.rs
+++ b/crates/fayalite/src/int.rs
@@ -32,8 +32,23 @@ mod sealed {
 pub const DYN_SIZE: usize = !0;
 pub type DynSize = ConstUsize<DYN_SIZE>;
 
-pub trait KnownSize: GenericConstUsize + Size<SizeType = Self> {
+pub trait KnownSize:
+    GenericConstUsize + sealed::SizeTypeSealed + sealed::SizeSealed + Default
+{
     const SIZE: Self;
+    type ArrayMatch<Element: Type>: AsRef<[Expr<Element>]>
+        + AsMut<[Expr<Element>]>
+        + BorrowMut<[Expr<Element>]>
+        + 'static
+        + Send
+        + Sync
+        + Eq
+        + Clone
+        + std::hash::Hash
+        + std::fmt::Debug
+        + IntoIterator<Item = Expr<Element>>
+        + TryFrom<Vec<Expr<Element>>>
+        + Into<Vec<Expr<Element>>>;
 }
 
 macro_rules! known_widths {
@@ -44,6 +59,7 @@ macro_rules! known_widths {
             v
         }> {
             const SIZE: Self = Self;
+            type ArrayMatch<Element: Type> = [Expr<Element>; Self::VALUE];
         }
     };
     ([2 $($rest:tt)*] $($bits:literal)+) => {
@@ -55,6 +71,7 @@ macro_rules! known_widths {
         known_widths!([$($rest)*] 1);
         impl KnownSize for ConstUsize<{2 $(* $rest)*}> {
             const SIZE: Self = Self;
+            type ArrayMatch<Element: Type> = [Expr<Element>; Self::VALUE];
         }
     };
 }
@@ -124,30 +141,24 @@ impl<const VALUE: usize> sealed::SizeSealed for ConstUsize<VALUE> {}
 
 impl<const VALUE: usize> sealed::SizeTypeSealed for ConstUsize<VALUE> {}
 
-impl<const VALUE: usize> SizeType for ConstUsize<VALUE>
-where
-    ConstUsize<VALUE>: KnownSize,
-{
-    type Size = ConstUsize<VALUE>;
+impl<T: KnownSize> SizeType for T {
+    type Size = T;
 }
 
-impl<const VALUE: usize> Size for ConstUsize<VALUE>
-where
-    ConstUsize<VALUE>: KnownSize,
-{
-    type ArrayMatch<Element: Type> = [Expr<Element>; VALUE];
+impl<T: KnownSize> Size for T {
+    type ArrayMatch<Element: Type> = <T as KnownSize>::ArrayMatch<Element>;
 
-    const KNOWN_VALUE: Option<usize> = Some(VALUE);
+    const KNOWN_VALUE: Option<usize> = Some(T::VALUE);
 
-    type SizeType = ConstUsize<VALUE>;
+    type SizeType = T;
 
     fn as_usize(_size_type: Self::SizeType) -> usize {
-        VALUE
+        T::VALUE
     }
 
     fn try_from_usize(v: usize) -> Option<Self::SizeType> {
-        if v == VALUE {
-            Some(ConstUsize)
+        if v == T::VALUE {
+            Some(T::SIZE)
         } else {
             None
         }
@@ -252,9 +263,7 @@ macro_rules! impl_int {
 
         impl<Width: KnownSize> $name<Width> {
             pub fn new_static() -> Self {
-                Self {
-                    width: Width::SizeType::default(),
-                }
+                Self { width: Width::SIZE }
             }
         }
 
@@ -526,9 +535,9 @@ pub trait BoolOrIntType: Type + sealed::BoolOrIntTypeSealed {
     fn new(width: <Self::Width as Size>::SizeType) -> Self;
     fn new_static() -> Self
     where
-        Self::Width: KnownSize,
+        Self::Width: KnownSize + Size<SizeType = Self::Width>,
     {
-        Self::new(<Self::Width as Size>::SizeType::default())
+        Self::new(Self::Width::default())
     }
     fn as_same_width_sint(self) -> SIntType<Self::Width> {
         SIntType::new(Self::Width::from_usize(self.width()))
diff --git a/crates/fayalite/tests/hdl_types.rs b/crates/fayalite/tests/hdl_types.rs
index 71450fc..4509146 100644
--- a/crates/fayalite/tests/hdl_types.rs
+++ b/crates/fayalite/tests/hdl_types.rs
@@ -1,11 +1,10 @@
 // SPDX-License-Identifier: LGPL-3.0-or-later
 // See Notices.txt for copyright information
-use fayalite::prelude::*;
-#[cfg(todo)]
 use fayalite::{
     bundle::BundleType,
     enum_::EnumType,
     int::{BoolOrIntType, IntType},
+    prelude::*,
     ty::StaticType,
 };
 use std::marker::PhantomData;
@@ -121,7 +120,6 @@ mod bound_kind {
 
 macro_rules! check_bounds {
     ($name:ident<$(#[$field:ident, $kind:ident] $var:ident: $($bound:ident +)*),*>) => {
-        #[cfg(todo)]
         #[hdl(outline_generated)]
         struct $name<$($var: $($bound +)*,)*> {
             $($field: bound_kind::$kind<$var>,)*