knowledge base

Golang Slice Tricks

Filtering with allocating

This trick uses the fact that a slice shares the same backing array and capacity as the original, so the storage is reused for the filtered slice. Of course, the original contents are modified.

1
2
3
4
5
6

b := a[:0]
for _, x := range a {
	if f(x) {
		b = append(b, x)
	}
}