* Improved lambda setter: Return value that is returned from the lambda.

include/cppmp/misc/setter.inl

@@ -157,8 +157,8 @@ namespace cppmp
                 inline cppmp_constexpr_lambda setter_lambda& operator = (const setter_lambda&) = default;
 
                 template<typename X_object, typename X_value>
-                constexpr void operator()(X_object&& obj, X_value&& value) const
-                    { lambda(std::forward<X_object>(obj), std::forward<X_value>(value)); }
+                constexpr decltype(auto) operator()(X_object&& obj, X_value&& value) const
+                    { return lambda(std::forward<X_object>(obj), std::forward<X_value>(value)); }
             };
 
             using lambda_type = T_lambda;