Macro let_else 

let_else!() { /* proc-macro */ }

A procedural macro that extends let-else with explicit else bindings.

Syntax

let_else!(PAT = EXPR else as REST { /* else block */ });
let_else!(PAT = EXPR else match { /* match arms */ });

REST can be a pattern (including |-separated patterns) or a single identifier. When match is used, provide full match arms for the else branch.

Examples

Simple else binding:

fn foo(value: Result<i32, String>) {
  let_else!(Ok(value) = value else as Err(err) {
    eprintln!("Error: {}", err);
    return;
  });
}

Complete else match:

fn bar(value: Result<i32, String>) {
  let_else!(Ok(value) = value else match {
    Err(err) => {
      eprintln!("Error: {}", err);
      return;
    }
  });
}

Notes

• The expression is evaluated once and reused in the else branch.
• The macro generates an unreachable arm for the success pattern.