concatCopyPreAllocate.go

concatCopyPreAllocate.go

func concatCopyPreAllocate(slices [][]byte) []byte {
    var totalLen int
    for _, s := range slices {
        totalLen += len(s)
    }
    tmp := make([]byte, totalLen)
    var i int
    for _, s := range slices {
        i += copy(tmp[i:], s)
    }
    return tmp
}