call/cc in golang

callCC.go

package main

func callCC[A, B, R any](f func(func(A) B) B, res *R) {
	defer func() {
		if err := recover(); err != nil {
			*res = err.(R)
		}
	}()
	f(func(a A) B {
		panic(a)
	})
}

func main() {
	var r = new(int)
	f := func(escape func(int) int) int {
		return 2 + escape(3)
	}
	println(f(func(x int) int {
		return x
	}))
	callCC[int, int, int](f, r)
	println(*r)
}