> On Feb 6, 2017, at 11:35 AM, Jordan Rose <[email protected]> wrote:
> 
>> 
>> On Feb 6, 2017, at 11:08, Daniel Duan <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 
>> 
>>> On Feb 6, 2017, at 10:58 AM, Jordan Rose <[email protected] 
>>> <mailto:[email protected]>> wrote:
>>> 
>>> I think I see Alex's point here. Optional chaining is still intended to be 
>>> a substitute for Objective-C's nil-swallowing, and therefore foo?.bar() 
>>> should not warn if 'bar' has a discardable result, even though there is 
>>> semantic information about whether the method was actually called. I think 
>>> that of the three things under consideration here:
>>> 
>>> 1. foo?.bar() should not warn
>>> 2. foo.map(baz) should warn
>>> 3. Ternaries should be consistent with non-ternaries
>>> 
>> 
>> I 100% agree with this analysis.
>> 
>>> #1 is the most important, at least to me. The Swift 3 change was to 
>>> sacrifice #2 in favor of #3, which I'm not sure I would have done, but I 
>>> wouldn't want to sacrifice #1 in favor of #2.
>>> 
>>> I wouldn't mind the model of the type being '@discardableResult 
>>> Optional<Void>' or whatever, but I think that's probably more work than 
>>> anyone wants to sign up for.
>> 
>> I’ll give this a go and report back. *crosses fingers*
> 
> I suspect this will entail making a new sugared type kind and then threading 
> it carefully through the constraint solver (hence why I said it's probably 
> more work than you want to take on).
> 

I was going to write a enhanced version of 
TypeBase::lookThroughAllAnyOptionalTypes(). Too hacky?

> Jordan

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