Why does spawn_blocking use + 'static instead of + 'a?

[OneOfOne]

I ran a little experiment and changed all 'static to 'a, and all the tests seemed to pass, also miri didn't complain.

For example:

  pub fn spawn_blocking<'a, F, R>(&self, func: F) -> JoinHandle<R>
    where
        F: FnOnce() -> R + Send + 'a,
        R: Send + 'a,
    {
        self.inner.blocking_spawner().spawn_blocking(self, func)
    }

[Darksonn]

That does not change behavior of any code that compiles today, but it makes it possible to write new code that is wrong but compiles.

Please see:
https://without.boats/blog/the-scoped-task-trilemma/