Generically take any duration?

[korken89]

Hi, I have issues with getting the following code to compile as I am unable to get the correct traits needed. Could you assist here @PTaylor-us ?

pub fn spawn_after<D: embedded_time::duration::Duration>(duration: D) -> Result<(), ()> {
    let instant = <MyClock as rtic::Monotonic>::now(); // Return an Instant<MyClock>

    // This addition seems to be the issue
    spawn_at(instant + duration, #(,#untupled)*)
}

[korken89]

We found the correct traits that were needed eventually. Would there be any way to make this simpler?

Solution:

pub fn spawn_after<D>(duration: D) -> Result<(), ()>
    where D: embedded_time::duration::Duration + embedded_time::fixed_point::FixedPoint,
       D::T: Into<<MyClock as embedded_time::Clock>::T>,
{
    let instant = <MyClock as rtic::Monotonic>::now();

    spawn_at(instant + duration, #(,#untupled)*)
}

[wbuck]

I did have a some what similar request. Would it be possible to export the TimeInt trait?

It would be beneficial when trying to create a custom type, i.e Rpm.

[PTaylor-us]

I want to allow easy generic usage of any Duration/Rate (including Generic) with only a embedded_time::Duration where clause. I'm assuming this is not possible because the Add implementation for Instant requires that the Duration impl FixedPoint. This will probably take me some time to figure out unless anyone can help me out. I feel like there's a trait pattern that is missing.

[PTaylor-us]

Proposed Solution

• move associated const SCALING_FACTOR out of FixedPoint
• move FixedPoint into Duration

This should allow this (eliminate the need to bind FixedPoint:

pub fn spawn_after<D>(duration: D) -> Result<(), ()>
    where D: embedded_time::duration::Duration,
       D::T: Into<<MyClock as embedded_time::Clock>::T>,
{
    let instant = <MyClock as rtic::Monotonic>::now();

    spawn_at(instant + duration, #(,#untupled)*)
}

@korken89 I'm not seeing a good way to eliminate the need for the Into binding, though.

[PTaylor-us]

This may not work fully. I wanted to move the const SCALING_FACTOR out of FixedPoint so Generic could also implement FixedPoint, but obviously, the scaling factor of the FixedPoint number must be accessible by the FixedPoint concrete type.

[PTaylor-us]

Current plan is to bind FixedPoint to Duration and Rate. Then I will remove the Duration and Rate implementations for the Generic versions.

[korken89]

Sounds interesting, I'll be lurking. :)

[PTaylor-us]

Completed for v0.13.0 release PR