https://play.golang.org/p/VWPb_AcgUrl
On Mon, 2018-12-10 at 20:14 -0600, Mark Volkmann wrote: > Here is some code that shows a part of what I'm trying to do. > https://goplay.space/#8piYtjsqveZ > > package main > > import ( > "fmt" > "reflect" > ) > > type Shape interface { > Area() float64 > Rotate(angle float64) > Translate(x, y float64) > } > > func ReportInterface(intfPtr interface{}) { > fmt.Println("type is", reflect.TypeOf(intfPtr)) // *main.Shape > value := reflect.ValueOf(intfPtr) > fmt.Println("value is", value) // <nil> > fmt.Println("method count is", value.NumMethod()) // 0, Why not 3? > } > > func main() { > var ptr *Shape > ReportInterface(ptr) > } > > On Mon, Dec 10, 2018 at 3:28 PM Dan Kortschak <d...@kortschak.io> > wrote: > > > > > No, it is possible, but you need to pass the pointer to the > > interface. > > You can then use reflect to interrogate the interface value. > > > > The bigger question, and one that would help here would be what is > > it > > that you are actually trying to achieve. > > > > On Mon, 2018-12-10 at 08:53 -0600, Mark Volkmann wrote: > > > > > > Yes, this is what I'm trying to do! > > > Perhaps this is not possible. > > > > > > On Sun, Dec 9, 2018 at 10:34 PM Robert Engels <rengels@ix.netcom. > > > com> > > > wrote: > > > > > > > > > > > > > > > I think what the OP wants is: > > > > > > > > type A interface{} > > > > type B interface{} > > > > > > > > ... > > > > PrintInterface(A) > > > > > > > > Meaning they want to pass the interface definition to some > > > > method. > > > > > > > > At least that’s what I am guessing. > > > > > > > > On Dec 9, 2018, at 9:22 PM, Space A. <reexist...@gmail.com> > > > > wrote: > > > > > > > > reflect/* is a bit tricky. Use pointer to get interface itself. > > > > > > > > package main > > > > > > > > import ( > > > > "fmt" > > > > "reflect" > > > > ) > > > > > > > > func main() { > > > > test := interface{}("test") > > > > printInterfaceValue(test) > > > > } > > > > > > > > func printInterfaceValue(i interface{}) { > > > > switch testing := i.(type) { > > > > case interface{}: > > > > fmt.Println("is interface, with value:", testing) > > > > case string: > > > > fmt.Println("is not interface") > > > > } > > > > > > > > fmt.Println("reflect.Type is", reflect.TypeOf(&i).Elem()) > > > > } > > > > > > > > Output: > > > > > > > > is interface, with value: test > > > > reflect.Type is interface {} > > > > > > > > > > > > > > > > > > > > > > > > > > > > понедельник, 10 декабря 2018 г., 5:05:12 UTC+3 пользователь > > > > Robert > > > > Engels > > > > написал: > > > > > > > > > > > > > > > > > > > > I mean reflect.Type not a type that is an interface. > > > > > > > > > > On Dec 9, 2018, at 6:53 PM, Space A. <reexi...@gmail.com> > > > > > wrote: > > > > > > > > > > Of course. When you "pass a value whose type implements the > > > > > interface" as > > > > > an interface argument to a function, you in fact pass an > > > > > *interface*. > > > > > > > > > > > > > > > воскресенье, 9 декабря 2018 г., 23:23:41 UTC+3 пользователь > > > > > Mark > > > > > Volkmann > > > > > написал: > > > > > > > > > > > > > > > > > > > > > > > > Is it possible to pass an interface to a function in Go? I > > > > > > don’t want to > > > > > > pass a value whose type implements the interface, I want to > > > > > > pass the > > > > > > interface. > > > > > > > > > > > > -- > > > > > > R. Mark Volkmann > > > > > > Object Computing, Inc. > > > > > > > > > > > -- > > > > > 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...@googlegroups.com. > > > > > For more options, visit https://groups.google.com/d/optout. > > > > > > > > > > -- > > > > 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. > > > > > > > > -- > > > > 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. > > > > > > > -- > > > R. Mark Volkmann > > > Object Computing, Inc. > > > > -- 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.
