Usage of /spawnpoint command

First off this may of been listed in a change update I missed
I thought that if you do /spawnpoint [playername] you would set your spawnpoint (in singleplayer) to the location you are currently at.

Currently you have to do /spawnpoint [playername] [x] [y] [z] i am of course aware you can just put it as /spawnpoint [playername] ~ ~ ~ but wondered if the just /spawnpoint [playername] was 1) possible for future or 2) meant to happen already and not.

Thanks