Object expression for abstract class without abstract members

Question

Given an interface without members

type IFoo = interface end

it's possible to create an instance using an object expression

let foo = { new IFoo }

However, it doesn't seem possible to do the same with an abstract class having no abstract members.

[<AbstractClass>]
type Foo() = class end

let foo = { new Foo() }

gives the error: Invalid object expression. Objects without overrides or interfaces should use the expression form 'new Type(args)' without braces. Well, we know that won't work either.

Here's a hacky workaround

let foo = { new Foo() with member __.ToString() = base.ToString() }

Is there a better way to create an object expression for an abstract type without abstract members?

Answer 1

I don't think there's a better way.

I also don't know why you'd want to do this (abstract class with no members), but I'll just assume you have your reasons and leave it at that :)