元組是不同類型的值的集合。 元組使用括號構造 (), 每個元組本身是類型簽名值 (T1, T2, ...), 這裡 T1, T2 是其成員的類型。 函數可以使用元組返回多個值，元組可以包含任意數量的值。

// Tuples can be used as function arguments and as return values
fn reverse(pair: (i32, bool)) -> (bool, i32) {
    // `let` can be used to bind the members of a tuple to variables
    let (integer, boolean) = pair;

    (boolean, integer)
}

fn main() {
    // A tuple with a bunch of different types
    let long_tuple = (1u8, 2u16, 3u32, 4u64,
                      -1i8, -2i16, -3i32, -4i64,
                      0.1f32, 0.2f64,
                      'a', true);

    // Values can be extracted from the tuple using tuple indexing
    println!("long tuple first value: {}", long_tuple.0);
    println!("long tuple second value: {}", long_tuple.1);

    // Tuples can be tuple members
    let tuple_of_tuples = ((1u8, 2u16, 2u32), (4u64, -1i8), -2i16);

    // Tuples are printable
    println!("tuple of tuples: {:?}", tuple_of_tuples);

    let pair = (1, true);
    println!("pair is {:?}", pair);

    println!("the reversed pair is {:?}", reverse(pair));

    // To create one element tuples, the comma is required to tell them apart
    // from a literal surrounded by parentheses
    println!("one element tuple: {:?}", (5u32,));
    println!("just an integer: {:?}", (5u32));
}