On Wednesday, 5 February 2014 at 15:56:44 UTC, Dicebot wrote:
On Wednesday, 5 February 2014 at 00:47:27 UTC, Walter Bright
wrote:
On 2/4/2014 2:39 PM, Dicebot wrote:
Also non-nullable types should be implicitly cast to nullable
parameters so you
don't always need to support all cases distinctively.
The difficulty comes when needing to transfer the nullability
of the argument to the nullability of the return type.
Implicit conversions don't help with that.
See inout.
Why can't inout be used for that as well? Same for pure & co.
In my opinion "inout" should be simply generic placeholder
saying "allow only code that works for all possible qualifiers
and preserve those in return type".
But nature of nullable is such that you rarely want to transfer
it. Is can be useful as return type sometimes but when you pass
it around and process it you almost always want it to be
non-nullable. There is no practical benefit in trying to
provide all-allowing API's.
If null becomes an invalid value for object references and
pointers, then we can use it to unambiguously mean "item does not
exist", and it becomes Just Another Value, so it is useful to
transfer in various circumstances.
