% Tuple Structs

Rust has another data type that's like a hybrid between a [tuple][tuple] and a
[struct][struct], called a ‘tuple struct’. Tuple structs have a name, but
their fields don’t:

```rust
struct Color(i32, i32, i32);
struct Point(i32, i32, i32);
```

[tuple]: primitive-types.html#tuples
[struct]: structs.html

These two will not be equal, even if they have the same values:

```rust
# struct Color(i32, i32, i32);
# struct Point(i32, i32, i32);
let black = Color(0, 0, 0);
let origin = Point(0, 0, 0);
```

It is almost always better to use a struct than a tuple struct. We would write
`Color` and `Point` like this instead:

```rust
struct Color {
    red: i32,
    blue: i32,
    green: i32,
}

struct Point {
    x: i32,
    y: i32,
    z: i32,
}
```

Now, we have actual names, rather than positions. Good names are important,
and with a struct, we have actual names.

There _is_ one case when a tuple struct is very useful, though, and that’s a
tuple struct with only one element. We call this the ‘newtype’ pattern, because
it allows you to create a new type, distinct from that of its contained value
and expressing its own semantic meaning:

```rust
struct Inches(i32);

let length = Inches(10);

let Inches(integer_length) = length;
println!("length is {} inches", integer_length);
```

As you can see here, you can extract the inner integer type through a
destructuring `let`, as we discussed previously in ‘tuples’. In this case, the
`let Inches(integer_length)` assigns `10` to `integer_length`.