Generic programming ramifications of const by default

[Roberto Mariottini]

Walter Bright wrote:
> Don Clugston wrote:
[...]
>> I want to create a function of the form
>>
>> A func(A.tupleof params);
>>
>> In the normal case, I don't want to modify any of the parameters. So 
>> they should all be const. With mutable-by-default, it's necessary to 
>> add 'const' to all of the tuple elements; it definitely adds _some_ 
>> complication to the most common case for metaprogramming.
> 
> I think you should be able to do:
>   A func(in A.tupleof params);
> 
[...]
> 
> It's not that it's worse, it's that there's an inconsistency. Having a 
> type mean one thing as a parameter and quite another as a local is 
> probably going to be a problem.

What about stating that all function parameters are "in" by default?
It should be fairly clear, then.

Ciao