func (as *asciiSet) contains(c byte) bool {
	return (as[c/32] & (1 << (c % 32))) != 0
}

// containsRune is a simplified version of strings.ContainsRune
// to avoid importing the strings package.
// We avoid bytes.ContainsRune to avoid allocating a temporary copy of s.
func containsRune(s string, r rune) bool {
	for _, c := range s {
		if c == r {
			return true
		}
	}
	return false
}

	// true
	// false
	// false
}

func ExampleContainsRune() {
	fmt.Println(bytes.ContainsRune([]byte("I like seafood."), 'f'))
	fmt.Println(bytes.ContainsRune([]byte("I like seafood."), 'ö'))
	fmt.Println(bytes.ContainsRune([]byte("去是伟大的!"), '大'))
	fmt.Println(bytes.ContainsRune([]byte("去是伟大的!"), '!'))
	fmt.Println(bytes.ContainsRune([]byte(""), '@'))
	// Output:
	// true
	// false
	// true
	// true
	// false

	{[]byte("a☺b☻c☹d"), '☻', true},
	{[]byte("aRegExp*"), '*', true},
}

func TestContainsRune(t *testing.T) {
	for _, ct := range ContainsRuneTests {
		if ContainsRune(ct.b, ct.r) != ct.expected {
			t.Errorf("ContainsRune(%q, %q) = %v, want %v",
				ct.b, ct.r, !ct.expected, ct.expected)
		}
	}
}

func TestContainsFunc(t *testing.T) {
	for _, ct := range ContainsRuneTests {