error spawn-outside-scope

spawn допустим только внутри scope { }.

What it means#

spawn is allowed lexically only inside scope { ... }, or as s.spawn(...) with s: &Scope (§8.5). Structured concurrency guarantees that child tasks finish before the scope exits. Background work belongs in node.background.

Example#

fn work() { }

fn main() {
  let h = spawn work()      // <- spawn-outside-scope
}

spawn-outside-scope

How to fix#

fn work() { }

fn main() io, time {
  scope {
    let h = spawn work()
    h.join()!
  }
}

Wrap the spawn in a scope block, or use node.background.spawn(...) for work that must outlive the caller.

See also#

• task-reuse
• send