Review: Query Result Form --> need COUNT ?

I am not sure if COUNT is allowed. So, if someone needs to find the 
cardinality of the solution set, does SPARQL (based on 1.406) allow this?
If not, would something like this work?

  SELECT COUNT
  WHERE ...

In a similar way, does it make sense to try allowing ASK as part of 
SELECT as follows:
 
  SELECT EXISTS
   WHERE ...

Thanks,
- Souri.