Seal the Peripheral trait

src/lib.rs

@@ -143,6 +143,8 @@ macro_rules! impl_peripheral_trait {
     ($type:ident) => {
         unsafe impl Send for $type {}
 
+        impl $crate::peripheral::sealed::Sealed for $type {}
+
         impl $crate::peripheral::Peripheral for $type {
             type P = $type;
 

src/modem.rs

@@ -1,6 +1,6 @@
 use core::marker::PhantomData;
 
-use crate::peripheral::Peripheral;
+use crate::peripheral::{sealed, Peripheral};
 
 #[cfg(not(esp32s2))]
 pub use split::*;
@@ -43,6 +43,8 @@ impl Modem {
 
 unsafe impl Send for Modem {}
 
+impl sealed::Sealed for Modem {}
+
 impl Peripheral for Modem {
     type P = Self;
 

src/peripheral.rs

@@ -131,7 +131,7 @@ impl<'a, T> DerefMut for PeripheralRef<'a, T> {
 ///
 /// `.into_ref()` on an owned `T` yields a `PeripheralRef<'static, T>`.
 /// `.into_ref()` on an `&'a mut T` yields a `PeripheralRef<'a, T>`.
-pub trait Peripheral: Sized {
+pub trait Peripheral: Sized + sealed::Sealed {
     /// Peripheral singleton type
     type P;
 
@@ -160,6 +160,8 @@ pub trait Peripheral: Sized {
     }
 }
 
+impl<T: DerefMut> sealed::Sealed for T {}
+
 impl<T: DerefMut> Peripheral for T
 where
     T::Target: Peripheral,
@@ -171,3 +173,7 @@ where
         self.deref_mut().clone_unchecked()
     }
 }
+
+pub(crate) mod sealed {
+    pub trait Sealed {}
+}