https://docs.google.com/presentation/d/1TqCv_ECXBVGw1XOQ-v6rVRyiYGczl4yhDCJIhNLpzaQ/edit#slide=id.gc7f218b544_1_409

go_practice_generics.go

package main

import "fmt"

func main() {
	ptr := Ptr[bool](false)
	fmt.Println(ptr)

	var sum int
	Apply[int]([]int{10, 20}, func(i, v int) {
		sum += v
	})
	fmt.Println(sum) // 30

	ns := []int{1, 2, 3, 4}
	ms := Filter[int](ns, func(i, v int) bool {
		return v%2 == 0
	})
	fmt.Println(ms) // [2 4]
}

func Ptr[T any](v T) *T {
	return &v
}

func Apply[T any](values []T, applyer func(int, T)) {
	for i, v := range values {
		applyer(i, v)
	}
}

func Filter[T any](values []T, filter func(int, T) bool) []T {
	var result []T
	for i, v := range values {
		if filter(i, v) {
			result = append(result, v)
		}
	}
	return result
}