import "crypto/sha256"

func main() {
    out := make([]byte, 64)
    h := sha256.New()
    hashed := h.Sum(out)

    hashed := sha256.New().Sum(out)
}

import "crypto/sha256"

func main() {
    arr := []int{1, 2, 3}
    out := make([]byte, 64)
    h := sha256.New()
    h.Write(arr)
    hashed := h.Sum(out)

    h2 := sha256.New()
    hashArr(h2, arr)
    hashed2 := h2.Sum(out)
}

func hashArr(h hash.Hash, b []byte) {
    h.Write(b)
}