resolved the conflict

lib/core/macros.nim

@@ -56,10 +56,10 @@ type
     nnkFromStmt,
     nnkIncludeStmt,
     
-    nnkBindStmt, nnkMixinStmt,
+    nnkBindStmt, nnkMixinStmt, nnkUsingStmt,
     nnkCommentStmt, nnkStmtListExpr, nnkBlockExpr,
     nnkStmtListType, nnkBlockType, nnkTypeOfExpr, nnkObjectTy,
-    nnkTupleTy, nnkRecList, nnkRecCase, nnkRecWhen,
+    nnkTupleTy, nnkTypeClassTy, nnkRecList, nnkRecCase, nnkRecWhen,
     nnkRefTy, nnkPtrTy, nnkVarTy,
     nnkConstTy, nnkMutableTy,
     nnkDistinctTy,

lib/pure/typetraits.nim

@@ -13,3 +13,5 @@
 proc name*(t: typedesc): string {.magic: "TypeTrait".}
   ## Returns the name of the given type
 
+proc arity*(t: typedesc): int {.magic: "TypeTrait".}
+  ## Returns the arity of the given type