函数选项模式

 使用通过返回函数的方式(闭包和变长参数)来对值进行初始化，扩展性较强，也可以让代码更加优雅。

package main

import "fmt"

type User struct {
	Name   string
	Age    int
	Height int
	Weight int
}

type Option func(*User)

func (u *User) WithOption(opts ...Option) {
	for _, opt := range opts {
		opt(u)
	}
}

func WithName(name string) Option {
	return func(u *User) {
		u.Name = name
	}
}

func WithAge(age int) Option {
	return func(u *User) {
		u.Age = age
	}
}

func WithHeight(h int) Option {
	return func(u *User) {
		u.Height = h
	}
}

func WithWeight(w int) Option {
	return func(u *User) {
		u.Weight = w
	}
}

func main() {
	var u = User{
		Name: "Jimmy",
		Age:  10,
	}
	u.WithOption(WithHeight(123), WithWeight(70))
	fmt.Println(u)
}