On Wed, Sep 2, 2020 at 3:45 AM targe...@gmail.com <target....@gmail.com> wrote: > > > Other people have said this too, but I want to emphasize that there > are not 4 potential states of an interface value. There are 2 > potential states: 1) interface does not hold any value, and is == nil; > 2) interface holds a value, and is != nil. > > Indeed, there are 2 states of interface observable from outside. Although one > of these observable states gets expressed through 2 states invisible to outer > world. Which isn't a problem on its own. > > > When you start talking about an interface as a fat pointer you are > talking about how those 2 states are implemented. There are other > possible implementations > > Yes. And that's not an issue on its own. The issue is, such implementation > detail kind of "leaks" sometimes and bites you when you don't expect. And it > does so because the way it gets constructed omits one specific detail of > conversion from pointer to interface.
I don't think that is correct. The implementation detail never leaks. An interface always either holds a valid value (is != nil) or does not hold a valid value (is == nil). I believe the confusion is due to the overloading of "nil". It means both an invalid interface and an invalid pointer, but you are permitted to store an invalid pointer in a valid interface. Ian -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAOyqgcVG%2BY8d9gtnR7%3DGmdN5eiPQ1ZGP3XoWYCjW2b%3Dbkj1z6w%40mail.gmail.com.
