Also, this should be in there anyway. It's a major API gap.
This is just your opinion, based on a very specific use case. Unless you have other arguments, I won't consider this feature a "major gap" in the API.
I'm really sorry to reject this request (don't worry, I do it all the time, it's not against you
), but I really need to be convinced that a feature will be useful to a majority of users before adding it. It might be absolutely necessary for you, but you should admit that your requirements are really specific and from a global point of view this function is really not the most important one to add in SFML.