Go 只读/只写channel

Go中channel能够是只读、只写、同时可读写的。

//定义只读的channel

read_only := make (<-chan int)

 

//定义只写的channel

write_only := make (chan<- int)

 

//可同时读写

read_write := make (chan int)

 

定义只读和只写的channel意义不大，通常用于在参数传递中，见代码：

package main

import (
    "fmt"
    "time"
)

func main() {
    c := make(chan int)
    go send(c)
    go recv(c)
    time.Sleep(3 * time.Second)
}
//只能向chan里写数据
func send(c chan<- int) {
    for i := 0; i < 10; i++ {
        c <- i
    }
}
//只能取channel中的数据
func recv(c <-chan int) {
    for i := range c {
        fmt.Println(i)
    }
}

 

若是将上面send方法和recv方法中的参数对调：

func send(c <-chanint) {

func recv(c chan<- int) {

编译就会报错：

./channel.go:18: invalid operation: c <- i (send to receive-only type <-chan int)

./channel.go:24: invalid operation: range c (receive from send-only type chan<- int)