From 054fca0e254379b5a0e7e03a28adab1eca7a9e9a Mon Sep 17 00:00:00 2001
From: John Wellbelove <john.wellbelove@etlcpp.com>
Date: Fri, 19 Dec 2025 08:26:27 +0000
Subject: [PATCH] Updated functional.h from the code in the inplace_function
 branch

---
 include/etl/functional.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/include/etl/functional.h b/include/etl/functional.h
index 9f7f811d..0f0172ec 100644
--- a/include/etl/functional.h
+++ b/include/etl/functional.h
@@ -143,6 +143,21 @@ namespace etl
   using unwrap_ref_decay_t = typename unwrap_ref_decay<T>::type;
 #endif
 
+  //***************************************************************************
+  // is_reference_wrapper
+  // Detect etl::reference_wrapper<T>
+  //***************************************************************************
+  template <typename T> 
+  struct is_reference_wrapper : etl::false_type {};
+  
+  template <typename T> 
+  struct is_reference_wrapper<etl::reference_wrapper<T> > : etl::true_type {};
+
+#if ETL_USING_CPP17
+  template <typename T>
+  inline constexpr bool is_reference_wrapper_v = is_reference_wrapper<T>::value;
+#endif
+
   //***************************************************************************
   /// unary_function
   //***************************************************************************