[MichaelGG]

It wouldn't be fine. It'd call the wrong method. The bytecode invokes the foo(object) one, but a naive decompiling would invoke foo(string). A cast would be required to get it to resolve correctly. Or am I misunderstanding?

[tokenizerrr]

I'm talking about decompiled code, which would turn out looking something like http://ideone.com/HCOLU4 which compiles and runs just fine. Maybe I am misunderstanding what you mean?