Macro async_instant

macro_rules! async_instant {
    ($id:expr, $category:expr, $name:expr $(, $key:expr => $val:expr)*) => { ... };
}

Convenience macro for the async_instant function, which can be used to emit an async instant event.

Example:

{
    let id = Id::new();
    async_instant!(id, c"foo", c"bar", "x" => 5, "y" => 10);
}

is equivalent to

{
    let id = Id::new();
    async_instant(
        id, c"foo", c"bar",
        &[ArgValue::of(c"x", 5), ArgValue::of("y", 10)]
    );
}