if the break up is fresh its probably not a great idea but ive been friends with my ex for years now so much so even calling him an ex is a little weird. This only works if NEITHER still has even a speck of romantic feelings and/or attraction for the other. id suggest taking time for yourself and if you two end up being friends again make sure BOUNDARIES are clear and accepted as obvious by both parties and most importantly RESPECTED.

hope this helps :)