Interfaces

Interfaces declare method signatures that types (or modules) can conform to via impl ... as ... (or module ... as ...). This is the basis for protocol-like surfaces such as iterators and Drop.

Full reference: interfaces.

Notes#

• Full reference: interfaces
• Dynamic dispatch (trait objects/vtables): not implemented yet

Syntax#

interface Len {
  fn len() -> i64;
}

struct Counter {
  n: i64,
}

impl Counter as Len {
  fn len (self: &Counter) -> i64 { return self.n; }
}

Examples#

Example: conformance + direct method call#

interface Len {
  fn len() -> i64;
}

struct Counter {
  n: i64,
}

impl Counter as Len {
  fn len (self: &Counter) -> i64 { return self.n; }
}

fn main () -> int {
  let c: Counter = Counter{ n: 3 };
  return c.len() as int;
}

See also#

• Full reference: interfaces
• Std protocols: interfaces