Consider for Unwrap and TryUnwrap

impl/src/try_unwrap.rs

@@ -123,6 +123,7 @@ pub fn expand(input: &DeriveInput, trait_name: &'static str) -> Result<TokenStre
     }
 
     let imp = quote! {
+        #[allow(unreachable_code)] // omit warnings for `!` and other unreachable types
         #[automatically_derived]
         impl #imp_generics #enum_name #type_generics #where_clause {
             #(#funcs)*

impl/src/unwrap.rs

@@ -118,6 +118,7 @@ pub fn expand(input: &DeriveInput, trait_name: &'static str) -> Result<TokenStre
     }
 
     let imp = quote! {
+        #[allow(unreachable_code)] // omit warnings for `!` and other unreachable types
         #[automatically_derived]
         impl #imp_generics #enum_name #type_generics #where_clause {
             #(#funcs)*

tests/try_unwrap.rs

@@ -1,4 +1,5 @@
 #![cfg_attr(not(feature = "std"), no_std)]
+#![cfg_attr(nightly, feature(never_type))]
 #![allow(dead_code)] // some code is tested for type checking only
 
 #[cfg(not(feature = "std"))]
@@ -128,3 +129,14 @@ pub fn test_try_unwrap_mut_2() {
 
     assert_eq!(value, Tuple::Double(255, 256));
 }
+
+#[cfg(nightly)]
+mod never {
+    use super::*;
+
+    #[derive(TryUnwrap)]
+    enum Enum {
+        Tuple(!),
+        TupleMulti(i32, !),
+    }
+}

tests/unwrap.rs

@@ -1,4 +1,5 @@
 #![cfg_attr(not(feature = "std"), no_std)]
+#![cfg_attr(nightly, feature(never_type))]
 #![allow(dead_code)] // some code is tested for type checking only
 
 use derive_more::Unwrap;
@@ -117,3 +118,14 @@ pub fn test_unwrap_mut_2() {
 
     assert_eq!(value, Tuple::Single(256));
 }
+
+#[cfg(nightly)]
+mod never {
+    use super::*;
+
+    #[derive(Unwrap)]
+    enum Enum {
+        Tuple(!),
+        TupleMulti(i32, !),
+    }
+}