# Objective
- Make working with `bevy_time` more ergonomic in `no_std` environments.
Currently `bevy_time` expects the getter in environments where time
can't be obtained automatically via the instruction set or the standard
library to be of type `*mut fn() -> Duration`.
[`fn()`](https://doc.rust-lang.org/beta/std/primitive.fn.html) is
already a function pointer, so `*mut fn()` is a _pointer to a function
pointer_. This is harder to use and error prone since creating a pointer
out of something like `&mut fn() -> Duration` when the lifetime of the
reference isn't static will lead to an undefined behavior once the
reference is freed
## Solution
- Accept a `fn() -> Duration` instead
## Testing
- I made a whole game on the Playdate that relies on `bevy_time`
heavily, see:
[bevydate_time](1b4f02adcd/src/lib.rs (L510-L546))
for usage of the Instant's getter.
---
## Showcase
<details>
<summary>Click to view showcase</summary>
https://github.com/user-attachments/assets/f687847f-6b62-4322-95f3-c908ada3db30
</details>
## Migration Guide
This is a breaking change but it's not for people coming from Bevy v0.15
### Small thank you note
Thanks to my friend https://github.com/repnop for helping me understand
how to deal with function pointers in `unsafe` environments
Co-authored-by: Wesley Norris <repnop@repnop.dev>
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