[RFC PATCH] add auto_bitmap

[Jeff Law]

On 11/14/13 07:52, Richard Biener wrote:
>>> Another advantage of this class is it puts the bitmap_head struct on the stack
>> instead of mallocing it or using a obstack.
>
> Hm, but then eventually you increase the lifetime of the bitmap
> until the scope closes.
Yea, but often that's when we're releasing them anyway ;-)  I don't 
think we've gone to too much trouble to try and release the bitmaps as 
soon as they're no longer needed.  Releasing at end of scope seems fine 
to me.

I'm a fan of RAII style code.  It's less error prone and often results 
in code that is easier to understand because the code isn't cluttered 
with resource de-allocation either in if bodies or in blocks reached by 
gotos.

Jeff