var convertibleTypes = []reflect.Type{reflect.TypeOf(time.Time{}), reflect.TypeOf(false), reflect.TypeOf([]byte{})}

// RegEx matches only numeric values
var numericPlaceholderRe = regexp.MustCompile(`\$\d+\$`)

func isNumeric(k reflect.Kind) bool {
	switch k {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return true
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		return true

	if funcName != aggFnCount {
		// All aggregation functions, except COUNT require a
		// numeric argument.

		// Here, we diverge from Amazon S3 behavior by
		// inferring untyped values are numbers.
		if !argVal.isNumeric() {
			if i, ok := argVal.bytesToInt(); ok {
				argVal.setInt(i)
			} else if f, ok := argVal.bytesToFloat(); ok {
				argVal.setFloat(f)
			} else {
				return errNonNumericArg(funcName)
			}
		}