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interface

The interface keyword declares an interface: a named contract consisting of method signatures (and optionally associated types/values) that conforming types must satisfy.

Syntax & Example​

interface Comparable {
    fn compare(other: &Self): i32;
}

struct Order(value: i64): Comparable {
    pub fn compare(other: &Order): i32 {
        if self.value < other.value { return -1; }
        if self.value > other.value { return 1; }
        return 0;
    }
}

Use Cases​

  • Defining shared behavior that multiple unrelated types can implement.
  • Decoupling callers from concrete types via the interface type.
  • Supporting polymorphic dispatch over a set of implementors.