From 90fb1657b994542c6fa3b05a961fa1adf4e08f8d Mon Sep 17 00:00:00 2001
From: Ernest <ernest.a.elgin.iv@gmail.com>
Date: Mon, 11 Jul 2022 15:10:26 -0400
Subject: [PATCH 1/2] Implements Sealed trait, with deliberations

---
 src/lib.rs | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index e048f871b8..9d1b34f876 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -653,7 +653,7 @@ pub type Result<T> = std::result::Result<T, Status>;
 /// This trait doesn't require `num::Zero` or `num::One` because some tensor
 /// types (such as `bool` and `String`) don't implement them and we need to
 /// supply custom implementations.
-pub trait TensorType: Default + Clone + Display + Debug + 'static {
+pub trait TensorType: private::Sealed + Default + Clone + Display + Debug + 'static {
     /// Internal only; do not use outside of the tensorflow crate.
     ///
     /// Tensor representation for this type. Normally `TensorDataCRepr` for types
@@ -684,6 +684,25 @@ pub trait TensorType: Default + Clone + Display + Debug + 'static {
     fn pack(data: &[Self], dims: &[u64]) -> Result<*mut tf::TF_Tensor>;
 }
 
+mod private {
+    pub trait Sealed {}
+
+    // impl Sealed for usize {}
+    // impl Sealed for bool {}
+    // impl Sealed for u8 {}
+    // impl Sealed for u16 {}
+    // impl Sealed for u32 {}
+    // impl Sealed for u64 {}
+    // impl Sealed for i8 {}
+    // impl Sealed for i16 {}
+    // impl Sealed for i32 {}
+    // impl Sealed for i64 {}
+    // impl Sealed for f32 {}
+    // impl Sealed for f64 {}
+
+    impl <T> Sealed for T{}
+}
+
 macro_rules! tensor_type {
     ($rust_type:ty, $tensor_type:ident, $zero:expr, $one:expr) => {
         impl TensorType for $rust_type {

From ef0261de5a7cbcc6939b38020c766669e776d333 Mon Sep 17 00:00:00 2001
From: Ernest <ernest.a.elgin.iv@gmail.com>
Date: Wed, 13 Jul 2022 10:44:07 -0400
Subject: [PATCH 2/2] Final Cleanup and Documentation

---
 src/lib.rs | 36 ++++++++++++++++--------------------
 1 file changed, 16 insertions(+), 20 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 9d1b34f876..d5025a5504 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -644,11 +644,26 @@ pub type Result<T> = std::result::Result<T, Status>;
 
 ////////////////////////
 
+/// A common implementation of the sealed supertrait programming pattern 
+/// (C-SEALED)
+/// 
+/// With this, implementations of `Sealed` are guarenteed to only exist in the
+/// current crate. This allows modifictation of the underyling traits in ways
+/// that would ordinarily be a breaking change for traits that are not sealed.
+/// 
+/// See https://rust-lang.github.io/api-guidelines/future-proofing.html#sealed-traits-protect-against-downstream-implementations-c-sealed
+ 
+mod private {
+    pub trait Sealed {}
+    
+    impl <T> Sealed for T{}
+}
+
 /// A Rust type that maps to a `DataType`.
 ///
 /// Currently, all implementors must *not* implement Drop (or transitively contain
 /// anything that does) and must be bit-for-bit compatible with the corresponding C
-/// type. Clients must not implement this trait.
+/// type. Clients cannot implement this trait.
 ///
 /// This trait doesn't require `num::Zero` or `num::One` because some tensor
 /// types (such as `bool` and `String`) don't implement them and we need to
@@ -684,25 +699,6 @@ pub trait TensorType: private::Sealed + Default + Clone + Display + Debug + 'sta
     fn pack(data: &[Self], dims: &[u64]) -> Result<*mut tf::TF_Tensor>;
 }
 
-mod private {
-    pub trait Sealed {}
-
-    // impl Sealed for usize {}
-    // impl Sealed for bool {}
-    // impl Sealed for u8 {}
-    // impl Sealed for u16 {}
-    // impl Sealed for u32 {}
-    // impl Sealed for u64 {}
-    // impl Sealed for i8 {}
-    // impl Sealed for i16 {}
-    // impl Sealed for i32 {}
-    // impl Sealed for i64 {}
-    // impl Sealed for f32 {}
-    // impl Sealed for f64 {}
-
-    impl <T> Sealed for T{}
-}
-
 macro_rules! tensor_type {
     ($rust_type:ty, $tensor_type:ident, $zero:expr, $one:expr) => {
         impl TensorType for $rust_type {