Effiziente Slice-Filterung ohne Allokation von neuem Speicher

package main
 
import "fmt"
 
func filterEven(numbers []int) []int {
	n := 0
	for _, x := range numbers {
		if x%2 == 0 {
			numbers[n] = x
			n++
		}
	}
	return numbers[:n]
}
 
func main() {
	nums := []int{1, 2, 3, 4, 5, 6}
	filtered := filterEven(nums)
	fmt.Println("Filtered:", filtered)
	fmt.Println("Original backing array modified:", nums)
}