Discussion: class member functions should be const by default

[marzojr]

I know that class are still not supported on cppfront; but this makes the discussion even more relevant.

One of the things that lambda functions (arguably) get right is making their operator() const by default and requiring mutable if you want to change data from the lambda.

This should be done also for cpp2 classes. This has the advantages of (1) making lambdas less of a special case, and (2) making const-correct code the default.

This is kind of related to issue #25 .

[hsutter]

That's the intent, and it just falls out of making in parameters the default. Classes will use explicit this which, like all parameters, defaults to in and therefore const.

I've added this to the Design note: const objects by default. Thanks!