define should be the keyword for manifest constants

[Steven Schveighoffer]

"Russell Lewis" wrote
> IMHO, it's better for a C++ programmer to say "I've never seen that 
> keyword, let me look up what it does," than to say "I know what that 
> does" - and be wrong.  Yes, you can re-teach them.  But if the keyword is 
> unfamiliar, then you re-teach them the *first* time that they see it, not 
> ages later when they stumble upon a subtle bug.

If I'm not mistaken, pure is a keyword in gcc already, and does not mean 
"manifest constant"

-Steve