From d0e097cd1d7100b2d2baae79e55e5e782b930ce8 Mon Sep 17 00:00:00 2001
From: Cameron Zwarich <cameron@lean-fro.org>
Date: Sun, 6 Jul 2025 06:24:24 -0700
Subject: [PATCH] chore: remove IRType.{isStruct,isUnion} (#9219)

These are used by the checker for `.ctor`, but I don't think that that
unboxed types will reuse `.ctor`, whose implementation details are
intimately connected to our runtime representation of objects.
---
 src/Lean/Compiler/IR/Basic.lean   | 8 --------
 src/Lean/Compiler/IR/Checker.lean | 2 +-
 2 files changed, 1 insertion(+), 9 deletions(-)

diff --git a/src/Lean/Compiler/IR/Basic.lean b/src/Lean/Compiler/IR/Basic.lean
index 26c100d2be..c643c6ba9a 100644
--- a/src/Lean/Compiler/IR/Basic.lean
+++ b/src/Lean/Compiler/IR/Basic.lean
@@ -100,14 +100,6 @@ def isIrrelevant : IRType → Bool
   | irrelevant => true
   | _ => false
 
-def isStruct : IRType → Bool
-  | struct _ _ => true
-  | _ => false
-
-def isUnion : IRType → Bool
-  | union _ _ => true
-  | _ => false
-
 end IRType
 
 /-- Arguments to applications, constructors, etc.
diff --git a/src/Lean/Compiler/IR/Checker.lean b/src/Lean/Compiler/IR/Checker.lean
index 7966dcb6af..3a2346c680 100644
--- a/src/Lean/Compiler/IR/Checker.lean
+++ b/src/Lean/Compiler/IR/Checker.lean
@@ -133,7 +133,7 @@ def checkExpr (ty : IRType) (e : Expr) : M Unit := do
       throw s!"constructor '{c.name}' has too many fields"
     if c.ssize + c.usize * usizeSize > maxCtorScalarsSize then
       throw s!"constructor '{c.name}' has too many scalar fields"
-    if !ty.isStruct && !ty.isUnion && c.isRef then
+    if c.isRef then
       checkObjType ty
       checkArgs ys
   | .reset _ x =>