Hi,

The Set<'a> was usable with any type in the previous version (unless I'm wrong). However, the following

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type foo() = class end
let a = foo()
let b = foo ()
let xs = Set.of_list [a ; b]

now raises the following exception :

System.ArgumentException: Failure during generic comparison: the type FSI_0138+foo does not implement the System.IComparable interface. This error may be arise from the use of a function such as 'compare', 'max' or 'min' or a data structure such as 'Set' or 'Map' whose keys contain instances of this type
à Microsoft.FSharp.Core.LanguagePrimitives.HashCompare.FailGenericComparison[T](Object obj)
à Microsoft.FSharp.Collections.SetTreeModule.add[A](FastFunc2`3 comparer, A k, SetTree`1 t)
à Microsoft.FSharp.Collections.SetTreeModule.mkFromEnumerator[T](FastFunc2`3 comparer, SetTree`1 acc, IEnumerator`1 e)
à Microsoft.FSharp.Collections.Set`1..ctor(IEnumerable`1 elements)
à <StartupCode$FSI_0138>.$FSI_0138._main() dans C:\Prog\FS\Lib\Script.fsx:ligne 17
stopped due to error

Was there any change in the F# compare function ? It seems it now requires IComparable<'a> to be implemented...

Julien.