Consider for From

JelteF · Aug 28, 2024 · 680b036 · 680b036
1 parent bc4932c
commit 680b036
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Showing 4 changed files with 39 additions and 4 deletions.
diff --git a/impl/src/from.rs b/impl/src/from.rs
@@ -172,6 +172,7 @@ impl<'a> Expansion<'a> {
                     });
 
                     Ok(quote! {
+                        #[allow(unreachable_code)] // omit warnings for `!` and unreachable types
                         #[automatically_derived]
                         impl #impl_gens derive_more::From<#ty> for #ident #ty_gens #where_clause {
                             #[inline]
@@ -192,6 +193,7 @@ impl<'a> Expansion<'a> {
                 });
 
                 Ok(quote! {
+                    #[allow(unreachable_code)] // omit warnings for `!` and other unreachable types
                     #[automatically_derived]
                     impl #impl_gens derive_more::From<(#( #field_tys ),*)> for #ident #ty_gens #where_clause {
                         #[inline]
@@ -234,6 +236,7 @@ impl<'a> Expansion<'a> {
                 let (impl_gens, _, where_clause) = generics.split_for_impl();
 
                 Ok(quote! {
+                    #[allow(unreachable_code)] // omit warnings for `!` and other unreachable types
                     #[automatically_derived]
                     impl #impl_gens derive_more::From<(#( #gen_idents ),*)> for #ident #ty_gens #where_clause {
                         #[inline]

diff --git a/tests/constructor.rs b/tests/constructor.rs
@@ -40,12 +40,16 @@ mod never {
     struct Tuple(!);
 
     #[derive(Constructor)]
-    struct Struct { field: ! }
+    struct Struct {
+        field: !,
+    }
 
     #[derive(Constructor)]
     struct TupleMulti(i32, !);
 
     #[derive(Constructor)]
-    struct StructMulti { field: !, other: i32 }
+    struct StructMulti {
+        field: !,
+        other: i32,
+    }
 }
-
diff --git a/tests/deref.rs b/tests/deref.rs
@@ -83,5 +83,7 @@ mod never {
     struct Tuple(!);
 
     #[derive(Deref)]
-    struct Struct { field: ! }
+    struct Struct {
+        field: !,
+    }
 }
diff --git a/tests/from.rs b/tests/from.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"))]
@@ -455,6 +456,20 @@ mod structs {
                 }
             }
         }
+
+        #[cfg(nightly)]
+        mod never {
+            use super::*;
+
+            #[derive(From)]
+            struct Tuple(i32, !);
+
+            #[derive(From)]
+            struct Struct {
+                field1: !,
+                field2: i16,
+            }
+        }
     }
 }
 
@@ -1787,5 +1802,16 @@ mod enums {
                 );
             }
         }
+
+        #[cfg(nightly)]
+        mod never {
+            use super::*;
+
+            #[derive(From)]
+            enum Enum {
+                Tuple(i8, !),
+                Struct { field1: !, field2: i16 },
+            }
+        }
     }
 }