From 8d2eef2b1e0075b70bf6afa74fddb01c4b5e48f1 Mon Sep 17 00:00:00 2001
From: mstembera <m_stembera@yahoo.com>
Date: Thu, 3 Apr 2025 19:50:23 -0700
Subject: [PATCH] Fix fused() all controll paths should return a value.

closes https://github.com/official-stockfish/Stockfish/pull/5973

No functional change
---
 src/nnue/nnue_feature_transformer.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/nnue/nnue_feature_transformer.h b/src/nnue/nnue_feature_transformer.h
index d2abd40fa..b9b422a65 100644
--- a/src/nnue/nnue_feature_transformer.h
+++ b/src/nnue/nnue_feature_transformer.h
@@ -194,6 +194,10 @@ fused(const typename VecWrapper::type& in, const T& operand, const Ts&... operan
         return fused<VecWrapper, ops...>(VecWrapper::add(in, operand), operands...);
     case Sub :
         return fused<VecWrapper, ops...>(VecWrapper::sub(in, operand), operands...);
+    default :
+        static_assert(update_op == Add || update_op == Sub,
+                      "Only Add and Sub are currently supported.");
+        return typename VecWrapper::type();
     }
 }