const?? When and why? This is ugly!

[Walter Bright]

Andrei Alexandrescu wrote:
> Walter Bright wrote:
>> If I may restate your case, it is that given function that does 
>> something with character arrays:
>>
>> int foo(string s);
>>
>> and you wish to pass a mutable character array to it. If foo was 
>> declared as:
>>
>> int foo(const(char)[] s);
>>
>> then it would just work. So why is it declared immutable(char)[] when 
>> that isn't actually necessary?
>>
>> The answer is to encourage the use of immutable strings. I believe the 
>> future of programming will tend towards ever more use of immutable 
>> data, as immutable data:
>>
>> 1. is implicitly sharable between threads
> 
> In fact const data is also implicitly sharable between threads.

No. You have to declare it "shared const" to make it sharable between 
threads.