Connect sink to toilet waste

Hi Guys,

I would like to add a basin next to my toilet but the only way I could do the waste is by hooking it up to the toilet waste.

I have seen that this is not necessarily recommended but is still "ok" but to do it I am not sure what the connecting part would be called.

I think it would be something like a reducing swept tee that changes the 40 mm basin waste to the 110 mm toilet waste???

Any advice would be appreciated.

Thanks

As above and also available as a straight: