Modified etl::is_delegate to inherit from etl::bool_constant

Author: jwellbelove

include/etl/private/delegate_cpp03.h

@@ -180,9 +180,8 @@ namespace etl
   /// is_delegate
   //***************************************************************************
   template <typename T>
-  struct is_delegate
+  struct is_delegate : etl::bool_constant<etl::is_base_of<delegate_tag, T>::value>
   {
-    static const bool value = etl::is_base_of<delegate_tag, T>::value;
   };
 
   //*************************************************************************
@@ -192,7 +191,8 @@ namespace etl
   class delegate;
 
   template <typename TReturn, typename TParam>
-  class delegate<TReturn(TParam)> : public private_delegate::call_if_impl<delegate<TReturn(TParam)>, TReturn, TParam>, public delegate_tag
+  class delegate<TReturn(TParam)> : public private_delegate::call_if_impl<delegate<TReturn(TParam)>, TReturn, TParam>, 
+                                    public delegate_tag
   {
   private:
 

include/etl/private/delegate_cpp11.h

@@ -95,16 +95,13 @@ namespace etl
   /// is_delegate
   //***************************************************************************
   template <typename T>
-  struct is_delegate
+  struct is_delegate : etl::bool_constant<etl::is_base_of<delegate_tag, T>::value>
   {
-    static constexpr bool value = etl::is_base_of<delegate_tag, T>::value;
   };
 
 #if ETL_USING_CPP17
-
   template <typename T>
   inline constexpr bool is_delegate_v = is_delegate<T>::value;
-
 #endif
 
   //*************************************************************************