Literally nothing wrong with the compiler here...

It compiles under c# 4 as well and still compiles if you assign the float literal 0.0f or the decimal literal 0.0m to the enum variable.

It doesn't even mind 0L, 0U or 0UL despite the fact that the underlying type of the enum is int.

Definitely contrary to the spec and quite shocking!

Thanks for pointing it out :)

This shouldn't compile, but it does under the MS compilers for both C# 2 and 3 (and probably 1 as well - I haven't checked). It shouldn't compile because only the literal 0 should be implicitly convertible to the default value of any enum. Here the decimal is 0.0. Just a little compiler bug. The result is to print Bar as that's the 0 value of the Foo.