That is not true. The generic version can have significant performance implications for low-level/tight-loop functions as it will avoid the indirection required for interface method dispatching (at the expensive of code explosion for common calls with lots of types).
> On Dec 27, 2020, at 11:31 AM, K. Alex Mills <k.alex.mi...@gmail.com> wrote: > > Since in this case the use of generics doesn't let you do anything new, I > would argue that the KISS principle applies and the non-generic version > should be preferred. > > I think a linter can be added to go vet to warn about instances like this one > (where the type parameter can be replaced by the type bound) to encourage > simplicity. > > But as Ian pointed out, in the version that takes a slice argument, using > generics does allow you to do something you couldn't do otherwise (without > reallocating the contents of the slice to effect a "cast" to []Stringer). In > this case using generics actually makes the caller's job simpler and improves > performance by avoiding the need for reallocation. > > On Sun, Dec 27, 2020 at 4:23 AM Arnaud Delobelle <arno...@gmail.com > <mailto:arno...@gmail.com>> wrote: > In my opinion, the issue is that there are two ways to express (almost) the > same thing and that in itself creates friction in the language. > > There may be a valid reason to choose one version over the other, but every > time it will be necessary to review the pros and cons of each alternative. > > If we could have "generics" without having to make this choice it would > unblock the whole thing as far as I am concerned. > > Cheers > > On Sun, 27 Dec 2020, 05:25 K. Alex Mills, <k.alex.mi...@gmail.com > <mailto:k.alex.mi...@gmail.com>> wrote: > While it depends on the final generics implementation, my understanding of > how things stand now is that Print would compile down to a separate chunk of > binary for each type T that is used. For instance, if you used Print[A] and > Print[B] in your code, they would each refer to separate binary > implementations in which T is replaced by A and B, respectively. > > Printi does not do this, so you should see a smaller binary. > > IIRC, Printi also has to do a bit of work to lookup the Stringer method on > the type inhabiting the interface. I don't think that creates a significant > performance hit, but I might be understating the overhead of interface > dispatch. A benchmark would help here (alas, I am on my phone). > > With respect for the concerns mentioned above, I don't see an argument for > preferring Print over Printi. However, there may other concerns which I am > unaware of. > > On Sat, Dec 26, 2020, 9:58 PM Elliot <z11i...@gmail.com > <mailto:z11i...@gmail.com>> wrote: > If we remove slice from OP's example: > > https://go2goplay.golang.org/p/KSJpRw1Lrmm > <https://go2goplay.golang.org/p/KSJpRw1Lrmm> > > func Print[T Stringer](s T) { > fmt.Print(s.String()) > } > > func Printi(s Stringer) { > fmt.Print(s.String()) > } > > Are these two equivalent? When should one be chosen over the other? > > On Thursday, 24 December 2020 at 04:41:16 UTC+8 Henrik Johansson wrote: > Why will interfaces be more idiomatic once generics lands? It remains to be > seen I guess but I could very well see the other way become the idiom. > > On Wed, 23 Dec 2020, 21:20 wilk, <w...@flibuste.net > <mailto:w...@flibuste.net>> wrote: > On 23-12-2020, Ian Lance Taylor wrote: > > On Wed, Dec 23, 2020 at 9:54 AM wilk <w...@flibuste.net > > <mailto:w...@flibuste.net>> wrote: > >> > >> https://go2goplay.golang.org/p/fTW3hJYNgfU > >> <https://go2goplay.golang.org/p/fTW3hJYNgfU> > >> > >> type Stringer interface { > >> String() string > >> } > >> > >> Print[T Stringer](s []T) > >> > >> Print(s []Stringer) > >> > >> Both forms works. > >> How to prevent double way to do the same things that can be confusing ? > > > > Both forms work but they mean two different things. > > > > Print(s []Stringer) takes a slice of the type Stringer. > > > > Print[T Stringer](s []T) takes a slice of some type T, where T > > implements Stringer. > > > > For example, if MyInt implements Stringer, and I have a []MyInt, then > > I can call Print[T Stringer](s []T) but I can't call Print(s > > []Stringer), because a []Stringer is not a []MyInt. > > I understand the differences. But i'm affraid someone who never used > Go before will use type parameters instead of interface which is more > idiomatic i think. > I mean it will be difficult to say, you could use type parameters but > you should use interface, or something like that... > I'm speaking about ease of learn Go2. > > -- > wilk > > -- > 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 > <mailto:golang-nuts%2bunsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/rs08pp%24p8m%241%40ciao.gmane.io > > <https://groups.google.com/d/msgid/golang-nuts/rs08pp%24p8m%241%40ciao.gmane.io>. > > -- > 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 > <mailto:golang-nuts+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/d044ae30-7254-4a86-9cba-1bc18eeb7fefn%40googlegroups.com > > <https://groups.google.com/d/msgid/golang-nuts/d044ae30-7254-4a86-9cba-1bc18eeb7fefn%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 > <mailto:golang-nuts+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/CALJzkY-asEOYK1_zgVzNJ4B37u17QX0hZr5vZGADe-vEJgTtQA%40mail.gmail.com > > <https://groups.google.com/d/msgid/golang-nuts/CALJzkY-asEOYK1_zgVzNJ4B37u17QX0hZr5vZGADe-vEJgTtQA%40mail.gmail.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 > <mailto:golang-nuts+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/CALJzkY9y%3DRyJ_C4Hm1tvHABcex%2B8o89ydBxL_NXrt2ubtLauLw%40mail.gmail.com > > <https://groups.google.com/d/msgid/golang-nuts/CALJzkY9y%3DRyJ_C4Hm1tvHABcex%2B8o89ydBxL_NXrt2ubtLauLw%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. 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