fn test_runes() {
    // Test basic ASCII + emoji
    r1 := 'hello🎅'.runes()
    assert r1.len == 6
    assert r1[0] == `h`
    assert r1[1] == `e`
    assert r1[2] == `l`
    assert r1[3] == `l`
    assert r1[4] == `o`
    assert r1[5] == `🎅`

    // Test empty string
    r2 := ''.runes()
    assert r2.len == 0

    // Test single character
    r3 := 'A'.runes()
    assert r3.len == 1
    assert r3[0] == `A`

    // Test Unicode characters
    r4 := 'café'.runes()
    assert r4.len == 4
    assert r4[0] == `c`
    assert r4[1] == `a`
    assert r4[2] == `f`
    assert r4[3] == `é`

    // Test multiple emojis
    r5 := '🎅🎄🎁'.runes()
    assert r5.len == 3
    assert r5[0] == `🎅`
    assert r5[1] == `🎄`
    assert r5[2] == `🎁`

    // Test mixed ASCII, Unicode and emojis
    r6 := 'hello世界🌍'.runes()
    assert r6.len == 8
    assert r6[0] == `h`
    assert r6[1] == `e`
    assert r6[2] == `l`
    assert r6[3] == `l`
    assert r6[4] == `o`
    assert r6[5] == `世`
    assert r6[6] == `界`
    assert r6[7] == `🌍`

    // Test special characters
    r7 := '\n\t'.runes()
    assert r7.len == 2
    assert r7[0] == `\n`
    assert r7[1] == `\t`

    // Test mathematical symbols
    r8 := 'α+β=γ'.runes()
    assert r8.len == 5
    assert r8[0] == `α`
    assert r8[1] == `+`
    assert r8[2] == `β`
    assert r8[3] == `=`
    assert r8[4] == `γ`
}

fn main() {
    test_runes()
}