Swift 1.2b2: Parameters which are of function type cannot have their parameters marked as @noescape

Originator:rix.rob
Number:rdar://19997680 Date Originated:28-Feb-2015 07:11 PM
Status:Open Resolved:
Product:Developer Tools Product Version:Xcode-beta (6D532l)
Classification:Other Bug Reproducible:Always
 
Summary:
Trying to work around rdar://19997577 I figured I’d write a function which applies one operand to another operand. That doesn’t fly because @noescape can’t be applied to parameters of parameters.


Steps to Reproduce:
1. Write this:
func apply<T, U>(@noescape f: T -> U, @noescape g: (T -> U) -> U) -> U {
	return g(f)
}

2. Oops, g’s parameter would need to be @noescape too!
3. Write this:
func apply<T, U>(@noescape f: T -> U, @noescape g: (@noescape T -> U) -> U) -> U {
	return g(f)
}

4. Hm, that’s not valid.
5. Write this:
func apply<T, U>(@noescape f: T -> U, @noescape g: (@noescape f: T -> U) -> U) -> U {
	return g(f)
}


Expected Results:
I expected something in this chain to work.


Actual Results:
None of it worked.


Regression:
N/A


Notes:
This is Damien’s fault. https://twitter.com/launchz/status/571822195120340992

Comments


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