Go Python样式生成器实现为通道：过早读取

我try 使用this之后的通道来实现Python风格的生成器:

package main

import (
    "fmt"
)

type ContainerIterable[T any] struct {
    content []T
}

func NewContainerIterable[T any]() *ContainerIterable[T] {
    return &ContainerIterable[T]{content: make([]T, 0)}
}

func (c *ContainerIterable[T]) Iterate() chan T {
    ch := make(chan T)
    go func() {
        for _, v := range c.content {
            ch <- v
        }
        close(ch)
    }()
    return ch
}

func (c *ContainerIterable[T]) Add(e T) {
    c.content = append(c.content, e)
}

func main() {
    c := NewContainerIterable[int]()

    for i := 0; i < 5; i++ {
        c.Add(i)
    }

    r := make([]int, 0)
    for v := range c.Iterate() {
        r = append(r, v)
    }

    for i := 0; i < 5; i++ {
        fmt.Println(i, r[i], i == r[i])
    }
}

它工作得很好，输出是

0 0 true
1 1 true
2 2 true
3 3 true
4 4 true

然而，当我改变时

r := make([]int, 0)

至

r := make([]int, 5)

结果是不同的:

0 0 true
1 0 false
2 0 false
3 0 false
4 0 false

我理解在第二种情况下，c.Iterate()在之前开始从频道读取

    go func() {
        for _, v := range c.content {
            ch <- v
        }

has a chance 至 send anything 至 channel. This does not apply 至 the first case since main() goroutine takes some time 至 reallocate space for r slice when append() is invoked.

Please advise how 至 adjust my code 至 make Iterate() work properly?