Re: [boost] 3-state boolean type

From: Douglas Gregor (gregod_at_[hidden])
Date: 2002-08-05 09:24:28

On Monday 05 August 2002 10:06 am, Richard Hadsell wrote:
> Actually, "whatever" says a lot.  Or is that too trendy?

That's quite trendy :)

> global namespace, because I don't want to write "if (x == boost::whatever)"
> all the time.

I'm getting the distinct feeling we need a syntax change. The condition in 
   if (x ==boost::whatever) 

will always return false in a boolean context, because x == boost::whatever 
results in the unnameable 3rd state, which evaluates false in a boolean 
context. Perhaps we should just disallow that syntax. 

For the record, to check against the 3rd state, use
  if (whatever(x))

> If you don't want to leave it to users to create their own appropriate
> typedefs or #defines for the third state, how about making the name of the
> third state a template parameter?  Then a single typedef could define the
> user's favorite names for both the tristate type and the third state.

How would you pass the name as a template parameter? 

        Doug