How to use function as map's key

dictionary, function, go, key

Solution

You can use `reflect`.

    import (
       "reflect"
       "math"
    )


    func foo () {
       table := make(map[uintptr] string)
       table[reflect.ValueOf(math.Sin)] = "Sin"
       table[reflect.ValueOf(math.Cos)] = "Cos"
       println(table[reflect.ValueOf(math.Cos)])
    }

Problem

How to use function as map's key? for example: ``` type Action func(int) func test(a int) { } func test2(a int) { } func main() { x := map[Action]bool{} x[test] = true x[test2] = false } ``` those code would show an error: `invalid map key type Action`

Original source