Const sucks

[Russell Lewis]

Walter Bright wrote:
> What we are trying to achieve:
> 
> a) utility for functional programming
> b) better modularity by self-documenting interfaces better
> c) be able to treat reference types as if they were value types (i.e. 
> strings should behave to the user like value types, even though they are 
> references)

Is there a way to express (for a pointer passed as a function parameter) 
"the callee is allowed to modify this object through the pointer, but 
the caller ensures that no other code will be modifying it at the same 
time"?   Sort of a "you have exclusive write access" modifier?  Is that 
a common enough case to even support?

Russ