On 7/13/18 5:49 PM, rikki cattermole wrote:
On 14/07/2018 9:28 AM, Manu wrote:
I've already contributed other points to this DIP in the way you
describe.
This one however is very strange, and I'm surprised you can find the
hand-wavy introduction of a new attribute without any sense of where
it's going to be okay. Or maybe, I'm surprised I'm the only one that
finds problem with that.
You are very much not alone.
I didn't articulate it very clearly, but I am super not happy with such
a new attribute.
It's a very simple process - @implicit is not invented as much as a given.
We need to distinguish a constructor from other constructors.
The constructor supports attributes.
Attributes are a mechanism for distinguishing declarations from other
declarations.
Ergo, an attribute is the mechanism of choice.
Done deal.
=====
If we don't like the use of an attribute, it means we somehow failed in
defining attributes in the first place. (I don't think we did;
attributes as defined in D are brilliant and currently underused.) It's
poor language design to define a mechanism for doing a category of Xs
and then explicitly avoiding it exactly when the opportunity of doing X
arises.
From that vantage point, the choice of an attribute to identify
implicit copy construction is unassailably obvious, and elucubrated
syntax inventions such as "@this", "this(ref this x)" are chucklesomely
profligate and ridiculously baroque.
Andrei
