[SR-15854] Compiler thinks function closure parameter default value "throws" when it's not

[mattyoung]

Previous ID	SR-15854
Radar	None
Original Reporter	@mattyoung
Type	Bug
Status	Resolved
Resolution	Duplicate

Environment

Xcode Version 13.3 beta 2 (13E5095k)

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug
Assignee	None
Priority	Medium

md5: 4c20bc25d194caaf0caaa25c7402115b

duplicates:

• SR-1534 Error: Call is to rethrows function, but a defaulted argument function can throw

Issue Description:

func f<Target: Comparable>(_ a: Target, _ b: Target, areInIncreasingOrder: (Target, Target) throws -> Bool = (<)) rethrows -> Bool {
    try areInIncreasingOrder(a, b)
}

#warning("Compiler bug: compiler think this is throws but it's not")
f(1, 2)    // !! Call can throw but is not marked with 'try'

see: https://forums.swift.org/t/how-to-give-the-last-parameter-its-default-to-operator-func-f-target-comparable-a-target-b-target-areinincreasingorder-target-target-throws-bool-target-rethrows/44967/2