This is a great write-up! Going from explaining the terms to applying the terms to the actual problems.
I learned a lot. Thanks. On Sunday, February 23, 2020 at 5:37:56 PM UTC+8, Axel Wagner wrote: > > Hi, > > I've wrote about the theoretical side of that here: > https://blog.merovius.de/2018/06/03/why-doesnt-go-have-variance-in.html > The post uses slices, but the same arguments apply to maps as well. > Specifically, while it *may* seem like you should be able to use a > map[string]int as a map[string]interface{}, if you *could*, you would also > have to explain what happens when you write something to it that is not an > int. i.e. how would this code behave: > https://play.golang.org/p/StJrbhmjCHh > > There really is no good answer to this. So as long as the type allows both > reading and writing, making map variant really isn't possible. > > On Sun, Feb 23, 2020 at 10:24 AM Glen Huang <hey...@gmail.com > <javascript:>> wrote: > >> Another slightly related topic: >> >> switch v := i.(type) { >> case map[string]interface{}, map[string]int: >> fmt.Print(v) >> } >> >> Ideally v is of type map[string]interface{}, but it's interface{} >> instead. >> >> On Sunday, February 23, 2020 at 5:12:27 PM UTC+8, Glen Huang wrote: >>> >>> Hi, >>> >>> I have a function that accepts an argument of type >>> map[string]interface{}, and I also have a value of type map[string]int. >>> >>> Currently it seems I can't directly pass the value to the function. Is >>> there anyway I can directly coerce it or a new value of the exact matching >>> type must be created? >>> >>> I find it quite surprising that you can directly assign any variables to >>> interface{} but not when they are both "scoped inside" a map or a slice. Is >>> the asymmetry by design? >>> >>> Regards >>> >> -- >> 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 golan...@googlegroups.com <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/golang-nuts/3bd425dd-1ca4-4bb3-8385-07c3aece5912%40googlegroups.com >> >> <https://groups.google.com/d/msgid/golang-nuts/3bd425dd-1ca4-4bb3-8385-07c3aece5912%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- 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/564ecf0e-652a-4c23-9ce8-985afa7adb7c%40googlegroups.com.
