D const design rationale

[Walter Bright]

Reiner Pope wrote:
> You mention functional programming a fair bit with respect to const, 
> which is nice to hear. But nothing in the current const system allows 
> you to declare a verifiably 'pure' function; can we expect some 
> annotation for functions which says 'this function doesn't read/write 
> any global variables?'

You're right, we're moving in the right direction, but we're not there yet.