'Migrating to the latest FSharp.Core generates warnings
I've just migrated my project to use FSharp.Core 6.0.3 instead of 6.0.1.
I noticed that now in my code there are warnings every time I refer to uint32 with a unit of measure. More specificaly:
LanguagePrimitives.UInt32WithMeasurefunctionuint32<cm>as a parameter type
I guess it's safe to set a compile flag to ignore this warning, but I'd like to understand what has happened and why this is now considered a problem.
The exact warning message is: FS0057: Experimental library feature, requires '--langversion:preview'. This warning can be disabled using '--nowarn:57' or '#nowarn "57"'.
Solution 1:[1]
Older versions of F# only supported units of measure for signed integer values (and floating point).
According to this comment on an F# language issue, units of measure are now supported experimentally for unsigned integers as well.
In playing around with an example, I noticed that you can avoid the warning by using uint<cm> instead of uint32<cm>, but I'm not sure if this is intentional.
Solution 2:[2]
My $0.02 to this: I've reviewed the fsharp GH repo and found the declaration of LanguagePrimitives.UInt32WithMeasure.
[<Experimental("Experimental library feature, requires '--langversion:preview'")>]
val inline UInt32WithMeasure: input: uint -> uint<'Measure>
However, the Experimental attribute was added in this commit, so I guess that FSharp.Core 6.0.1 must have been created before that and therefore it doesn't report the warning.
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | Brian Berns |
| Solution 2 | Alojzy Leszcz |