reflection - Golang: Function to determine the arity of functions? -

is possible write function determine arity of arbitrary functions, such that:

1.

func mult_by_2(x int) int {       return 2 * x } fmt.println(arity(mult_by_2)) //prints 1 

2.

func add(x int, y int) int {       return x + y } fmt.println(arity(add)) //prints 2 

3.

func add_3_ints(a, b, c int) int {       return b + + c } fmt.println(arity(add_3_ints)) //prints 3 

you can write such function using reflect package:

import (     "reflect" )  func arity(value interface{}) int {     ref := reflect.valueof(value)     tpye := ref.type()     if tpye.kind() != reflect.func {         // define own logic here         panic("value not function")     }     return tpye.numin() }