I did some more thinking about the whole trait/boundary stuff and reallized that we don't need the GUI to handle the generic-ness of a trait object since only 1 platform will ever be used in a binary. What do you think of the following:
1. Define a platform trait
2. Each platform defines a zero-sized struct implementing the trait (ex `WebPlatform`).
3. Create an ifdef'd type alias on those structs:
```
// gui/src/platform/mod.rs
#[cfg(feature = "web")]
pub type CurrentPlatform = web::WebPlatform;
#[cfg(feature = "desktop")]
pub type CurrentPlatform = desktop::DesktopPlatform;
#[cfg(feature = "mobile")]
pub type CurrentPlatform = mobile::MobilePlatform;
```
4. Add a compile time assertion that `CurrentPlatform` implements `Platform`.
Pros:
- We don't end up working around async trait objects
- We define what functions are needed for a platform
- We save a little on binary size by avoiding a fully generic solution.
Cons:
- The trait does not really do much other than being a collection of functions.
- In some ways it seems like what we're currently doing but with extra steps.
liamwarfield
sam