package main

import (
	"fmt"
	"golang.org/x/exp/constraints"
	"reflect"
)

func main() {
	p := Point{2, 1, 3}
	fmt.Println("p 的类型是:", reflect.TypeOf(p)) // p 的类型是: main.Point
	ScaleAndPrint(p)
}

func Scale[E constraints.Integer](s []E, c E) []E {
	r := make([]E, len(s))
	for i, v := range s {
		r[i] = v * c
	}
	return r
}

type Point []int32

func (p Point) String() string {
	// Details not important.
	return ""
}

func ScaleAndPrint(p Point) {
	r := Scale(p, 2)
	//等价于
	//r := Scale[int32](p, 2)
	fmt.Println("r 的类型是:", reflect.TypeOf(r)) // r 的类型是: []int32
}