> > Are you sure that's the only edge-case? Because this thread is kinda long > and there might even be things we are not thinking about.
In the original discussion above I see one opinion toward comparing headers and four toward by element values (like strings). I didn't see any additional edge cases listed. The usecase you mentioned above seems - to me - to be served by a > map[string]*T just fine. Did I misunderstand it? Each path represented as a slice of coordinates could be easily encoded to a string and compared that way. As far as resource expenses go, we'd need benchmarks to say much. I understand looking at expensive cases too, but that doesn't mean that there aren't smaller regular use cases. Goroutines can be overused too. Matt On Wednesday, January 31, 2018 at 10:24:30 AM UTC-6, rog wrote: > > On 30 January 2018 at 23:19, <matthe...@gmail.com <javascript:>> wrote: > >> - When slices can be compared, they can be used as map keys. What > happens > >> if the contents of a slice are changed after it has been added to a > map? > > > > > > I’m not too familiar with Go map internals, but my thought is the key > hash > > would depend on the backing array values. Go maps also allow reading the > > keys back using iteration so the slice backing array (up to length) > would > > have to be copied. If the slice contents are changed then that would be > a > > different key and the original key would be intact. > > Note that copying the slice contents to make a map key implies > that using a slice as a map key might imply copying a whole tree, > which seems rather expensive to me (especially as it might end up > using more memory than the original if some elements are duplicated, > unless an alias-aware copy algorithm is used which would be > more expensive still) > > BTW you can already do something like this: > https://play.golang.org/p/q4bz8-AckN3 > > You can even do it without reflect, which I'll leave as an exercise > for the reader :) > -- 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.
