OK thank you, that confirms what I was thinking. Indeed it's not a common need. I wanted to know if it was possible to rewrite https://pkg.go.dev/github.com/stretchr/testify/assert#Nil with a "nillable" constraint instead of "interface{}".
Le jeudi 22 décembre 2022 à 14:43:51 UTC+1, axel.wa...@googlemail.com a écrit : > On Thu, Dec 22, 2022 at 2:24 PM Pierre Durand <pierre...@gmail.com> wrote: > >> Same question for `len()`: is there a way to declare a constraint that >> matches types that support `len()` ? > > > For this, the workaround you posted works, at least. It's not convenient, > but it also does not seem like a common need - again I'd be kind of curious > what you want it for. > > >> >> Le jeudi 22 décembre 2022 à 14:23:22 UTC+1, Pierre Durand a écrit : >> >>> Is there a way to declare a "nillable" constraint that matches all types >>> that can be nil (pointer, slice, map, etc.) ? >>> >>> I would like to write a function, that receives a parameter (with a >>> generic type), and check if this parameter is nil. >>> I found a very ugly way to write it: https://go.dev/play/p/0g0SoTlBEgs >>> The problem: the map type needs more than 1 type, so I need to provide >>> the 3 types when I call the `IsNil()` function/ >>> Is there a better way ? >>> >>> Yes I know I could use `any`, and check with reflect if the value inside >>> the interface is nil. >>> But I want to know if it's possible to do it with generics. >>> >>> Thank you. >>> >> -- >> > 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...@googlegroups.com. >> > To view this discussion on the web visit >> https://groups.google.com/d/msgid/golang-nuts/5101cdb3-601a-4eec-b278-5be07a891590n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/golang-nuts/5101cdb3-601a-4eec-b278-5be07a891590n%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/da2eea56-65b6-4534-af8b-1b58b95d6d56n%40googlegroups.com.
