From 06057b59ae0cec834924f8cbfc21792c7fb794e3 Mon Sep 17 00:00:00 2001
From: John Wellbelove <john.wellbelove@etlcpp.com>
Date: Sat, 20 Dec 2025 09:39:50 +0000
Subject: [PATCH] Synchronised etl::invoke_result with that in the
 etl::inplace_function branch

---
 include/etl/invoke.h | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/include/etl/invoke.h b/include/etl/invoke.h
index 3f86350c..efd0dc07 100644
--- a/include/etl/invoke.h
+++ b/include/etl/invoke.h
@@ -183,19 +183,34 @@ namespace etl
 
   //****************************************************************************
   /// invoke_result<TFunction, TArgs...>
-  template <typename TFunction, typename ... TArgs> 
-  struct invoke_result;
+  template <typename TFunction, typename, typename... TArgs> 
+  struct invoke_result
+  {
+    using type = void;
+  };
 
+  //*******************************************
   template <typename TFunction, typename... TArgs>
   struct invoke_result<TFunction,
                        etl::void_t<decltype(etl::invoke(etl::declval<TFunction>(), etl::declval<TArgs>()...))>,
-    TArgs...> 
+                       TArgs...> 
   {
     using type = decltype(etl::invoke(etl::declval<TFunction>(), etl::declval<TArgs>()...));
   };
 
+  //*******************************************
+  // Specialization to allow `etl::type_list<...>` as the second template parameter.
   template <typename TFunction, typename... TArgs>
-  using invoke_result_t = typename invoke_result<TFunction, TArgs...>::type;
+  struct invoke_result<TFunction,
+                       etl::void_t<decltype(etl::invoke(etl::declval<TFunction>(), etl::declval<TArgs>()...))>,
+                       etl::type_list<TArgs...>> 
+  {
+    using type = decltype(etl::invoke(etl::declval<TFunction>(), etl::declval<TArgs>()...));
+  };
+
+  //*******************************************
+  template <typename TFunction, typename... TArgs>
+  using invoke_result_t = typename invoke_result<TFunction, void, TArgs...>::type;
 
   //****************************************************************************
   /// is_invocable<TFunction, TArgs...>