change split_type def

include/eve/arch/cpu/logical_wide.hpp

@@ -82,7 +82,9 @@ namespace eve
     using combined_type = logical<wide<Type, typename Cardinal::combined_type>>;
 
     //! Type representing a logical wide of the same type but with a cardinal half the size
-    using split_type    = logical<typename wide<Type, Cardinal>::split_type>;
+    template<typename N = Cardinal>
+    requires (N::Value > 1)
+    using split_type = logical<typename wide<Type, N>::split_type>;
 
     //! @brief Generates a eve::wide from a different type `T` and cardinal `N`.
     //! If unspecified, `N` is computed as `expected_cardinal_t<T>`.

include/eve/arch/cpu/wide.hpp

@@ -68,16 +68,6 @@ namespace eve
   struct EVE_MAY_ALIAS wide
       : detail::wide_storage<as_register_t<Type, Cardinal, abi_t<Type, Cardinal>>>
   {
-    private:
-    // split_type does not exist on cardinals of size 1
-    // this function returns a void_t if the split_type does not exist
-    template <typename T, typename N>
-    static constexpr auto get_split_type() noexcept
-    {
-      if constexpr (N::value > 1) return wide<T, typename N::split_type>{};
-    }
-
-    public:
     using storage_base = detail::wide_storage<as_register_t<Type, Cardinal, abi_t<Type, Cardinal>>>;
 
     //! The type stored in the register.
@@ -102,7 +92,9 @@ namespace eve
     using combined_type = wide<Type, typename Cardinal::combined_type>;
 
     //! Type representing a wide of the same type but with a cardinal half the size
-    using split_type = decltype(get_split_type<Type, Cardinal>());
+    template<typename N = Cardinal>
+    requires (N::Value > 1)
+    using split_type = wide<Type, typename N::split_type>;
 
     //! @brief Generates a eve::wide from a different type `T` and cardinal `N`.
     //! If unspecified, `N` is computed as `expected_cardinal_t<T>`.