I agree, it would be awesome, but I have no idea how this could be accomplished. The problem is, we have a tradeoff with no uniformly best solution. Typing more arguments before the using clause constrains the type for the implicit search which might be needed to make it pass. Typing more arguments after the using clause means that the implicit search had a chance to constrain or instantiate some type variables, which gives better expected types for these arguments. Better expected types might be needed to typecheck lambdas or to do implicit search in the arguments, for instance. So the best (in fact only) solution is to fix a left-to-right order and stick to it. Or else existing programs will start breaking.