if s[i] < ' ' || s[i] > '~' {
			return false
		}
	}
	return true
}

// asciiToLower returns the lowercase version of s if s is ASCII and printable,
// and whether or not it was.
func http2asciiToLower(s string) (lower string, ok bool) {
	if !http2isASCIIPrint(s) {
		return "", false
	}
	return strings.ToLower(s), true
}

// A list of the possible cipher suite ids. Taken from