Look inside of None-delimited groups when examining types

serde_derive/src/internals/mod.rs

@@ -8,8 +8,17 @@ mod case;
 mod check;
 mod symbol;
 
+use syn::Type;
+
 #[derive(Copy, Clone)]
 pub enum Derive {
     Serialize,
     Deserialize,
 }
+
+pub fn ungroup(mut ty: &Type) -> &Type {
+    while let Type::Group(group) = ty {
+        ty = &group.elem;
+    }
+    ty
+}