> but I don't see ImmutableList, etc. Why .NET doesn't have an ImmutableList either (the ImmutableBag type is an unordered collection). This is because unlike

> but I don't see ImmutableList, etc. Why .NET doesn't have an ImmutableList either (the ImmutableBag type is an unordered collection). This is because unlike with hash-tables you always need to lock the entire structure when mutating a List/Vector (with hashtables you only need to lock the specific bin/bucket).