On Wed, Jun 24, 2020 at 9:34 AM Robert Engels <reng...@ix.netcom.com> wrote:
> Generics will not solve this fully anyway - you’ll still need reflection. > Why not just return empty if the user doesn’t pass a struct? > > That sounds like a bug waiting to happen. I have a library with a similar reflection-related use-case involving reflection, which currently panics when it gets a non-struct-type. It *would* be nice to have compile-time type-checking, if possible. > On Jun 24, 2020, at 8:29 AM, Pee Jai <p...@pjebs.com.au> wrote: > > > Here is my use case: > https://godoc.org/github.com/rocketlaunchr/react#UnmarshalState > > That function has an argument that accepts only a struct. I use the > reflect package to iterate over the structs fields (and also to check if it > actually is a struct). The function has notapplicability for non-structs. > > Currently I have to notify the user via documentation that only a struct > is allowed since the type is officially an `interface{}`. This is very > crude. > > If there was a way to add a type constraint for only structs, then I don't > need to use documentation, notwithstanding the use of reflect package to > iterate over the struct fields. > > On Wednesday, June 24, 2020 at 10:34:40 AM UTC+10, Ian Lance Taylor wrote: >> >> On Mon, Jun 22, 2020 at 7:08 PM Pee Jai <p...@pjebs.com.au> wrote: >> > >> > I can't find a way to constrain for just structs. I don't want >> primitives. >> >> The design draft doesn't provide any mechanism for a type constraint >> to match any arbitrary struct type, and not any other kind of type. >> >> But it's not clear why that would be useful. The only things you can >> do with a value of an arbitrary struct type are things that you can do >> with a value of any arbitrary type. >> >> 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/e86e677b-784d-47c5-b8b9-aedc37977ba5o%40googlegroups.com > <https://groups.google.com/d/msgid/golang-nuts/e86e677b-784d-47c5-b8b9-aedc37977ba5o%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/8013EEB8-78E6-455D-B846-8A826682B879%40ix.netcom.com > <https://groups.google.com/d/msgid/golang-nuts/8013EEB8-78E6-455D-B846-8A826682B879%40ix.netcom.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/CANrC0BgyoPvEWJEOOrJwt-3qfLvSxc6CX9yLoYBPxYZV8GBZLg%40mail.gmail.com.
