Macro with

macro_rules! with {
    ($token:expr, $category:expr, { $($body:tt)* }) => { ... };
}

Records a categorized measurement of the passed body, in category on token.

Example:

fn process(cogs: &Cogs, item: &Item) {
    let mut token = cogs.timed(ResourceId::Relay, AppFeature::Transactions);

    // The entire body is categorized as `processing`.
    relay_cogs::with!(token, "processing", {
        let success = do_something(&item);
    });

    // Not categorized.
    if success {
        do_something_else(&item);
    }
}