C# Language Design: explicit interface implementation of an event

Question

Small question about C# language design :))

If I had an interface like this:

interface IFoo {   int Value { get; set; } } 

It's possible to explicitly implement such interface using C# 3.0 auto-implemented properties:

sealed class Foo : IFoo {   int IFoo.Value { get; set; } } 

But if I had an event in the interface:

interface IFoo {   event EventHandler Event; } 

And trying to explicitly implement it using field-like event:

sealed class Foo : IFoo {   event EventHandler IFoo.Event; } 

I will get the following compiler error:

error CS0071: An explicit interface implementation of an event must use event accessor syntax

I think that field-like events is the some kind of dualism for auto-implemented properties.

So my question is: what is the design reason for such restriction done?

Answer 1

Interesting question. I did some poking around the language notes archive and I discovered that this decision was made on the 13th of October, 1999, but the notes do not give a justification for the decision.

Off the top of my head I don't see any theoretical or practical reason why we could not have field-like explicitly implemented events. Nor do I see any reason why we particularly need to. This may have to remain one of the mysteries of the unknown.