E3009

Record pattern cannot contain only .., use wildcard pattern _ instead.

Erroneous example

struct Point {
  x: Int
  y: Int
}

fn process_point(p: Point) -> Unit {
  match p {
    { .. } => println("Got a point")
  //^~~~~~
  // Error: Record pattern cannot contain only `..`, use wildcard pattern `_` instead.
  }
}

Suggestion

Use the wildcard pattern _ instead of { .. }:

struct Point {
  x: Int
  y: Int
}

fn process_point(p: Point) -> Unit {
  match p {
    _ => println("Got a point")
  }
}

You can also use { .. } along with other fields if you want to match specific fields:

fn process_point(p: Point) -> Unit {
  match p {
    { x: 0, .. } => println("Point on y-axis")
    _ => println("Other point")
  }
}