sync_writes isn't working correctly when different values for function parameters are used about cached HOT 5 OPEN

Ah no problem at all! P.S. I love this crate, it's an absolute joy to use. I do think I would find the sync_value_writes = true feature very useful. For my use case I don't think having two locks would meaningfully impact performance.

from cached.

This is currently working as intended, but I understand the desire to only synchronize on a per key basis. Support for this could be added (preferably behind another macro arg like sync_value_writes = true) by updating the macro to wrap the individual cached values in another mutex. That would come with the caveat of requiring two locks for every read

from cached.

If you go here the docs say this:

use cached::proc_macro::cached;

/// Cache an optional function. Only `Some` results are cached.
/// When called concurrently, duplicate argument-calls will be
/// synchronized so as to only run once - the remaining concurrent
/// calls return a cached value.
#[cached(size=1, option = true, sync_writes = true)]
fn keyed(a: String) -> Option<usize> {
    if a == "a" {
        Some(a.len())
    } else {
        None
    }
}

Which would indicate that it should function as I am describing no? But yes I see your point about requiring two locks...

from cached.

Yes, sorry the docs are incorrect!

from cached.

The effect of that option is here: when true, the lock is just held for the function execution instead of being released for others to read

from cached.