[swift-users] Looping through all values between UInt8.min and UInt8.max

[Erica Sadun]

> On Apr 8, 2016, at 3:48 AM, tuuranton--- via swift-users <swift-users at swift.org> wrote:
> 
> print(UInt8.min) //0
> 
> print(UInt8.max) //255
> 
> 
> 
> //Is there an easy way to loop between all values
> 
> //between (and including both) UInt8.min and UInt8.max?
> 
> 
> 
> //This doesn't work.
> 
> //Runtime crash because UInt8.max has no successor.
> 
> for i in UInt8.min...UInt8.max {
> 
>     print(i)
> 
> }
> 
> 

Easy? No. 

// Range Index has no valid successor
for i in UInt8.min ... UInt8.max {
    print(i)
}

// '...' cannot be applied to two 'UInt8' operands
for i in UInt8.min ... UInt8.max as ClosedInterval {
    print(i)
}

// Stops at 254
for i in UInt8.min ..< UInt8.max {
    print(i)
}


This works, but ugh:

for i : Int in numericCast(UInt8.min)...numericCast(UInt8.max) {
    guard let j: UInt8 = UInt8(i) else { fatalError("Nope") }
    print(j)
}

cc'ing in a few people to the white courtesy range phone.

-- E


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