More generally, this is https://github.com/golang/go/issues/10989.
Such ineffectual assignments can be detected using https://github.com/gordonklaus/ineffassign. An analysis showed that only a small fraction of such were bugs, making the backwards-incompatible language change not worthwhile. @ianlancetaylor: It's interesting that gccgo gives an error for the case given in this thread. Does it also flag other "assigned and not used", like func main() { x := 0 _ = x x = 1 } ? On Sunday, June 26, 2016 at 9:55:13 PM UTC+2, Ian Lance Taylor wrote: > > On Sat, Jun 25, 2016 at 12:34 PM, Val <dele...@gmail.com <javascript:>> > wrote: > > Hello > > It seems that this code doesn't compile : > > > > func main() { > > var err error > > err = f() > > } > > > > prog.go:8: err declared and not used > > > > > > but this one does : > > > > func main() { > > var err error > > g := func() { > > err = f() > > } > > g() > > } > > > > Is the function binding regarded as a "use"? Or does escape analysis > decide > > to not check too deep about never-read variables? > > > > Whether expected or not, I supposed this compiler behavior won't change, > > because of the Go1 compatibility promise. > > While the rest of this thread gives something of an explanation, I > think this is a bug, and I think it could be fixed in a future > release. This is https://golang.org/issue/3059. > > The gccgo compiler does give an error for this code. > > 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. For more options, visit https://groups.google.com/d/optout.
