From f93adb57a2ed109045fad58afdf646b99bb5a47c Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Tue, 25 Jul 2023 16:50:56 +0200
Subject: [PATCH] Improve performance of `FunctionOf.unapply`

[Cherry-picked a0c3469cbadf19b7c5eb8db5fa9983ba24187415]
---
 compiler/src/dotty/tools/dotc/core/Definitions.scala | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/compiler/src/dotty/tools/dotc/core/Definitions.scala b/compiler/src/dotty/tools/dotc/core/Definitions.scala
index f094063c97c7..5e4b854fc9e2 100644
--- a/compiler/src/dotty/tools/dotc/core/Definitions.scala
+++ b/compiler/src/dotty/tools/dotc/core/Definitions.scala
@@ -1110,10 +1110,10 @@ class Definitions {
       ft.dealias match
         case ErasedFunctionOf(mt) =>
           Some(mt.paramInfos, mt.resType, mt.isContextualMethod)
-        case _ =>
-          val tsym = ft.dealias.typeSymbol
+        case dft =>
+          val tsym = dft.typeSymbol
           if isFunctionSymbol(tsym) && ft.isRef(tsym) then
-            val targs = ft.dealias.argInfos
+            val targs = dft.argInfos
             if (targs.isEmpty) None
             else Some(targs.init, targs.last, tsym.name.isContextFunction)
           else None