Go泛型学习笔记

Go泛型内容不多可类比C++这种编程语言，共编写了泛型函数，泛型类型、接口约束、处理不同类型的值、处理泛型切片的常见demo举例

1、泛型函数

交换两个值

func Swap[T int | int32 | int64](a, b T) (T, T) {
	return b, a
}

func main() {
	a, b := 1, 2
	a, b = Swap(a, b)
	fmt.Println(a, b)

	x, y := "hello", "world"
	x, y = Swap(x, y) //编译不通过,因为泛型没有加入
	fmt.Println(x, y)
}

2、泛型类型

package main

import "fmt"

//int | int32 | int64 | float32 | float64

type Stack[T int | int32] struct {
	elements []T
}

func (s *Stack[T]) Push(element T) {
	s.elements = append(s.elements, element)
}

func (s *Stack[T]) Pop() (T, bool) {
	if len(s.elements) == 0 {
		var zero T
		return zero, false
	}
	element := s.elements[len(s.elements)-1]
	s.elements = s.elements[:len(s.elements)-1]
	return element, true

}

func main() {
	intStack := &Stack[int]{}
	intStack.Push(123)
	intStack.Push(456)
	fmt.Println(intStack.Pop())
	fmt.Println(intStack.Pop())

}

3、接口约束

package main

import "fmt"

type Comparable[T comparable] interface {
	Compare(a, b T) int
}

type IntComparator struct{}

func (ic IntComparator) Compare(a, b int) int {
	if a < b {
		return -1
	} else if a > b {
		return 1
	}
	return 0
}

func main() {
	ic := IntComparator{}
	fmt.Println(ic.Compare(1, 2))
	fmt.Println(ic.Compare(3, 4))
	fmt.Println(ic.Compare(8, 6))

}

4、处理不同类型的值

package main

import "fmt"

func Add[T, U int | string | float32 | float64](a T, b U) string {
	return fmt.Sprintf("%v+%v", a, b)
}

func main() {
	fmt.Println(Add(10, 20))
	fmt.Println(Add("Hello", 5))
	fmt.Println(Add(3.13, 3.74))
}

5、处理泛型切片

package main

import "fmt"

func PrintSlice[T int | int32 | int64 | string](slice []T) {
	for _, v := range slice {
		fmt.Println(v)
	}

}

func main() {
	intSlice := []int{1, 2, 3, 4}
	stringSlice := []string{"Go", "Lang", "Generics"}
	PrintSlice(intSlice)
	PrintSlice(stringSlice)
}