Currently watching Bart De Smet's explanation of IQueryable and he mentioned Existential Types (which I've been curious about for some time). After reading the answers to this question I'm just wondering if this is a way to construct it in C#:
public abstract class SomeExistentialType
{
private SomeExistentialType() { }
public abstract int Foo();
public ExistentialType Create()
{
return new ConcreteType1();
}
private class ConcreteType1: SomeExistentialType
{
public override int Foo()
{
//some implementation...
}
}
private class ConcreteType1: SomeExistentialType
{
public override int Foo()
{
//some implementation...
}
}
private class ConcreteType1: SomeExistentialType
{
public override int Foo()
{
//some implementation...
}
}
}
The idea is that if all of the concrete classes are defined as private nested classes (or maybe just internal classes) then you are forced to only use the interface.
