Note for posterity: Other methods of method equality fall in the same problem, such as detailed in: https://stackoverflow.com/questions/9643205/how-do-i-compare-two-functions-for-pointer-equality-in-the-latest-go-weekly
Proof: https://go.dev/play/p/aeeRKfderY2 On Monday, November 7, 2022 at 10:09:26 AM UTC-8 John wrote: > Thanks Ian for being generous with your time in answering this. I'll see > if I can drum up another way to make that check work. > > Cheers and have a good rest of your day. > On Monday, November 7, 2022 at 10:02:28 AM UTC-8 Ian Lance Taylor wrote: > >> On Mon, Nov 7, 2022 at 9:24 AM John <johns...@gmail.com> wrote: >> > >> > Or maybe I'm just doing something wrong. >> > >> > I have a struct implementing generics where methods return the next >> method to execute. >> > >> > For tests, I wanted to make sure the returned method was the one >> expected, so I was using this: >> > >> > nextStageName := >> runtime.FuncForPC(reflect.ValueOf(nextStage).Pointer()).Name() >> > (where "nextStage" is the next method) >> > >> > Here is a simple non-generic version where I get what I expect: >> > https://go.dev/play/p/kimGRS7xiP2 >> > >> > result: main.(*AStruct).NextStage-fm): >> > >> > Here is probably a slightly convoluted generic version that does not: >> > https://go.dev/play/p/TUHUaZywki0 >> > >> > result: main.(*GenericStruct[...]).Stage.func1 >> > >> > In that version, it seem to give me the name of the method that >> returned the next method. >> > >> > Any idea what is (or what I'm doing) wrong? >> >> I'm not sure that runtime.FuncForPC is going to work here. What it is >> reporting is a function literal defined within the Stage method (that >> is what the "func1" means). What is happening is that the Stage >> method is returning a function literal that invokes the NextStage >> method. This is due to details of how generic functions are compiled, >> and may change from release to release. In general FuncForPC is a >> fairly low level operation that has no way to avoid these sorts of >> compilation details. I don't know if there is a way to do what you >> want to do. >> >> 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/bf7f9802-0dd6-4ef0-ad7c-fbc6ba00feb4n%40googlegroups.com.
