any news on const/invariant?

[Walter Bright]

Derek Parnell wrote:
> The simple fact is that 
> 
>    const type funcname();
> 
> looks ambiguous. It LOOKS like it could mean either that funcname() returns
> a const type OR that funcname() is const but returns a non-const type.
> 
> Once you know the rules you can workout what is intended, but it is not as
> intuitive as you might like it to be.
> 
> Will it really be so hard to provide syntax that is not so ambiguous?
> 
> Also, what is the syntax for a const function that returns a const type?

The rule for constructing a const type is to enclose that type in 
parentheses, so:
	const const(type) funcname();
or:
	const(type) funcname()const;
or:
      const
      {
	const(type) funcname();
      }

> Walter, your efforts to achieve simplicity are being thwarted by the
> results being simplistic.

I think it is thwarted by people believing it is far more complicated 
than it actually is. For example, in the above case, you have to use 
const twice, because there are two different things in the same 
declaration you want to be const. Forget about const as a storage class 
for the moment, and just think of const as a type constructor. To make a 
type const,
	const(T)
and it will all follow from there.