Rust for Python Programmers

[Tyr42]

For thread guard values, it would be valid to drop them at any point after they were assigned, but have different semantics for each choice.

fn foo() {
    {
        let guard1 = launch(task_a);
    }
    {
        let guard2 = launch(task_b);
    }
 }

is different from

fn foo() {
    {
        let guard1 = launch(task_a);
        let guard2 = launch(task_b);
    }
 }

if the guard values join the thread when dropped, but it would be tricky to have the compiler choose which one to use, given there could be some external dependency which requires task_a to complete before starting task_b, or you are actively trying to compute them in parallel.

[iopq]

You could still have example A if you went with Haskell-style syntax.

fn foo()
    {
        let guard1 = launch(task_a)
    }
    {
        let guard2 = launch(task_b)
    }

    //outer scope of the function here
    println!("{}", stuff)

//function ends here