On Thursday, January 6, 2022 at 9:44:05 PM UTC+8 tapi...@gmail.com wrote:
> On Thursday, January 6, 2022 at 9:40:49 PM UTC+8 Brian Candler wrote: > >> So to be more specific, I think you're asking why this code works: >> https://gotipplay.golang.org/p/kuYzzx4EJY1 >> >> Sorry, I made a mistake in interpreting the spec. It also says: >> >> "The type set of the empty interface is the set of all types." >> >> Therefore, the type set of the intersection { int; any } is int - and >> hence f[int] is allowed. >> >> But the set of specific types >> <https://tip.golang.org/ref/spec#Structure_of_interfaces> is empty: >> >> "An interface specification which contains type elements >> <https://tip.golang.org/ref/spec#Interface_types> defines a (possibly >> empty) set of *specific types*. Loosely speaking, these are the >> types T that appear in the interface definition in terms of the form T, ~T, >> or in unions of such terms." >> >> The type set and the set of specific types can be different. Examples are >> given where one is empty and the other is non-empty: >> >> interface{ int; m() } // *[specific type]* int (but type set is empty >> because int has no method m) >> interface{ int; any } // no specific types (intersection is empty) *[even >> though the type set is not empty]* >> >> *Items in [italics/brackets] are my additions* >> > > > The type set and the set of specific types can be different > > This is true. > > > interface{ int; any } // no specific types (intersection is empty) *[even > though the type set is not empty]* > > I don't think this is true. In my opinion, the method set of specific > types of interface{ int; any } are both {int}. > sorry a typo: it should be the method set and specific types of interface{ int; any } are both {int}. -- 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/24b410b6-879e-4f0b-9156-e6279f3bcb61n%40googlegroups.com.
