[SR-1491] Implement support for SE-0080: Failable Numeric Conversion Initializers

[lattner]

Previous ID	SR-1491
Radar	rdar://problem/27382197
Original Reporter	@lattner
Type	Bug
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Standard Library
Labels	Bug, StarterBug
Assignee	ultramiraculous (JIRA)
Priority	Medium

md5: dbe7a5ce117acb5a606ae7c92abbdfc0

Issue Description:

The new initializers on primitive types as proposed in SE-0080 has been accepted:
https://github.com/apple/swift-evolution/blob/master/proposals/0080-failable-numeric-initializers.md

It would be great to get this implemented.

[swift-ci]

Comment by Chris Williams (JIRA)

Working on this here:

#2742

[lattner]

It looks like the integer part of this is done, but the FP components are still missing.

[benrimmington]

Chris Williams has implemented:

• SE-0067 (1/5) - Failable initializers for Fixed->Fixed #2963

• SE-0080 (2/5) - Failable initializers for Float->Float #2977

• SE-0080 (3/5) - Failable initializers for Float->Int #3356

• SE-0080 (4/4) - Failable initializers for Float->Int #4314

#4314 is open, the others are merged.

[jtbandes]

ultramiraculous (JIRA User), now that 4314 has been merged, is this done?

[swift-ci]

Comment by Chris Williams (JIRA)

Yeah I guess there was a question on the PR about if it should end up in Swift 3.1, but it's at least fixed for 4.0? Because of that I was also unsure of how I should do the changelog/Swift Evolution status updates.

[jtbandes]

Did your changes not already make it into 3.1 since master was merged today?

[swift-ci]

Comment by Chris Williams (JIRA)

Oh interesting. I thought 3.1 was branched off and there would need to be another PR to do a cherry-pick.