wiki/dev/lang/rust/Struct.md

# Struct.

# Types.

## Classic.

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

```rust
let mut green = ColorClassicStruct {
  red:   0,
  green: 255,
  blue:  0,
}

green.red = green.blue;
```

## Tuple.

Have no field names.

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

let x = Point(0, 0, 0);
```

## Unit-like.

Have nothing. TODO: add use-cases.

```rust
struct AlwaysEqual;

let subject = AlwaysEqual;
```

# Shortcuts.

## Field-init.

Copy values with the same name.

```rust
fn create_color(red: i32, green: i32, blue: i32) -> ColorClassicStruct {
  ColorClassicStruct {
    red,
    green,
    blue,
  }
}
```

## Struct update.

Copy the rest of the struct.

```rust
let color2 = ColorClassicStruct {
  red: 255,
  ..color1
};
```

# Logic.

You can write logic in structs.

```rust
struct Package {
  sender_country:    String,
  recipient_country: String,
  fee: u32
}

impl Package {
  fn is_international(&self) -> bool {
    self.sender_country != self.recipient_country
  }
}
```