D const design rationale

[Walter Bright]

eao197 wrote:
> Adding 'pure' modificator to D can lead, IMHO, to the following 
> alternatives:
> 1) nobody would use 'pure' at top level of modules/libraries/frameworks, 
> because any top-level function/method would use some 'impure' function 
> inside, or
> 2) it is necessary to introduce some constructs into language to define 
> 'logical pureness' -- function will be marked as pure, but can use 
> impure calls inside. Like 'mutable' keyword in C++ used for 'logical 
> constantness'.

I think you're probably right.