This IMHO isn't a bug as the behavior is not completely defined. Joanna
mentioned that Args is not generic, but it actually is, once you address it
from global namespace - as it inherits the T type (while not used anywhere):
NSStringFromClass(Event<NSString>.Args.self)
NSStringFromClass(Event<NSDate>.Args.self)
-->
_TtGCC14__lldb_expr_375Event4ArgsCSo8NSString__
_TtGCC14__lldb_expr_375Event4ArgsCSo6NSDate__
Which is the root of the problem - you are currently not actually using the
same class under different event types. It then makes a static property an
issue as you are not able to distinguish these two scenarios with current
language:
- is the stored property the same for all variations of the Args class?
- or does each type has its own stored property?
I can think of cases for both. And this is (from what I understood is the core
of the problem).
@Joanna - in this particular case, I don't see the benefit of Args.empty over
Args() as you currently create a new instance all the time. If the arguments
are not intended to be generic, much better solution is to do something like:
class EventArgs {
public static let empty = Args()
}
class Event<T> {
typealias Args = EventArgs
}
> On Sep 17, 2017, at 11:59 PM, Félix Cloutier via swift-evolution
> <[email protected]> wrote:
>
> I always thought that this was a bug, but I can't find it on bugs.swift.org,
> so I'd love to know if it's meant to stay this way or not.
>
>> Le 16 sept. 2017 à 06:32, Joanna Carter via swift-evolution
>> <[email protected]> a écrit :
>>
>> Greetings
>>
>> Old chestnut, sort of partially solved but still problems.
>>
>> Now we can nest types in generic types, what I want is :
>>
>> class Event<typeT>
>> {
>> class Args
>> {
>> public static let empty = Args() // error : Static stored properties not
>> supported in generic types
>> }
>> }
>>
>> But the static let is not directly in the generic class.
>>
>> So, I end up doing another convoluted workaround in the shape of :
>>
>> class Event<typeT>
>> {
>> class Args
>> {
>> public static var empty: Args
>> {
>> return Args()
>> }
>> }
>> }
>>
>> The main difference is that I have to create a new instance on every call to
>> Args.empty instead of returning the same one.
>>
>> Is this an oversight or as intended, with the hope of fixing it in a future
>> version
>>
>> Joanna
>>
>> --
>> Joanna Carter
>> Carter Consulting
>>
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>> [email protected]
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>
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