[SR-2522] Function attribute @escaping does not apply to function type aliases

[swift-ci]

Previous ID	SR-2522
Radar	None
Original Reporter	Andreas Grosam (JIRA User)
Type	Bug
Status	Resolved
Resolution	Duplicate

Additional Detail from JIRA

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

md5: b7d39839f9b0f82a87ae2c84cf3d9bbf

duplicates:

• SR-2316 typealias for block type not defaulting to @NoEscape

Issue Description:

A typealias name which declares a function type used as a parameter type in another function modified with attribute `@escaping` yields a compiler error, which IMHO is not correct.

The following code demonstrates the issue:

{code: code:title=Swift|linenumbers=true|firstline=000}
internal struct Foo<T> {
typealias ClosureType = (T) -> ()

func foo(f: ClosureType) {}
func foo2(f: @escaping ClosureType) {} // error: @escaping attribute only applies to function types
func foo3(f: @escaping (T)-> ()) {}
}