src/TraitExpressionBuilder.ts

@@ -5,26 +5,32 @@ import { TraitExpression } from "./TraitExpression"
 import { Extendable, StaticMembers } from "./util"
 
 
-type SpreadSupertraits<T> = (
-    T extends [infer Trait, ...infer Rest]
+type SpreadSupertraits<Traits> = (
+    Traits extends [
+        infer El extends Trait<any, any, any, any>,
+        ...infer Rest,
+    ]
         ? [
-            ...Trait.Supertraits<Trait>,
-            Trait,
+            ...Trait.Supertraits<El>,
+            El,
             ...SpreadSupertraits<Rest>,
         ]
         : []
 )
 
 type TraitsUniq<Traits> = (
-    Traits extends [...infer Rest, infer Trait]
-        ? IsTraitInTupleFromRight<Rest, Trait> extends true
+    Traits extends [
+        ...infer Rest,
+        infer El extends Trait<any, any, any, any>,
+    ]
+        ? IsTraitInTupleFromRight<Rest, El> extends true
             ? TraitsUniq<Rest>
-            : [...TraitsUniq<Rest>, Trait]
+            : [...TraitsUniq<Rest>, El]
         : []
 )
 type IsTraitInTupleFromRight<Traits, T> = (
-    Traits extends [...infer Rest, infer Trait]
-        ? IsEqual<Trait, T> extends true
+    Traits extends [...infer Rest, infer El]
+        ? IsEqual<El, T> extends true
             ? true
             : IsTraitInTupleFromRight<Rest, T>
         : false