Values inside 'as' patterns are disposed multiple times

[auduchinok]

let mutable isDisposed = false

let d = { new System.IDisposable with
            member x.Dispose() =
                printfn $"{isDisposed}"
                isDisposed <- true }

do
    use a as b = d
    ()

yields

False
True
val mutable isDisposed : bool = true
val d : System.IDisposable
val it : unit = ()

[albert-du]

So today I learned there is no limit on the number of “as” patterns used on a value

let mutable isDisposed = false

let d = { new System.IDisposable with
            member x.Dispose() =
                printfn $"{isDisposed}"
                isDisposed <- true }

do
    use a as b as c as d as e as f as g = d
    ()
// False
// True
// True
// True
// True
// True
// True

SharpLab
“d” gets disposed 7 times