I'm new to Go and I would like to understand why the code snippet below does not compile. What is the Go way of accepting a function as a function argument that may have any return type?
package main
func main() {
test(a) // Error: cannot use a (type func() string) as type func() interface {} in argument to test
test(b) // Error: cannot use b (type func() int) as type func() interface {} in argument to test
}
func a() string {
return "hello"
}
func b() int {
return 1
}
func test(x func() interface{}) {
// some code...
v := x()
// some more code....
}
Play: https://play.golang.org/p/CqbuEZGy12
My solution based on Volker's answer:
package main
import (
"fmt"
)
func main() {
// Wrap function a and b with an anonymous function
// that has an empty interface return type. With this
// anonymous function, the call signature of test
// can be satisfied without needing to modify the return
// type of function a and b.
test(func() interface{} {
return a()
})
test(func() interface{} {
return b()
})
}
func a() string {
return "hello"
}
func b() int {
return 1
}
func test(x func() interface{}) {
v := x()
fmt.Println(v)
}