Duration from `checked_duration_since` cannot be added with `Instant`?

[korken89]

Hi,

I am working on moving RTIC to embedded time, however the following trivial code gives a weird trait bound error that I need help with.
What is causing this as is there a recommended fix?

Code:

let now = M::now();

match instant.checked_duration_since(&now) {
    None => {
        // ...
    }
    Some(dur) => {
        let new_instant = now + dur; // <-- error

        // ...
    }
}

Error:

error[E0277]: the trait bound `rtic_core::monotonic::Generic<<M as rtic_core::monotonic::Clock>::T>: FixedPoint` is not satisfied
  --> src/tq.rs:71:47
   |
71 |                         let new_instant = now + dur;
   |                                               ^ the trait `FixedPoint` is not implemented for `rtic_core::monotonic::Generic<<M as rtic_core::monotonic::Clock>::T>`
   |
   = note: required because of the requirements on the impl of `Add<rtic_core::monotonic::Generic<<M as rtic_core::monotonic::Clock>::T>>` for `Instant<M>`

[PTaylor-us]

Completed v0.13.0 release PR