Add serialize feature to bevy_color

[pablo-lua]

What problem does this solve or what need does it fill?

Make serde optional for users. If they don't want, they not require it

What solution would you like?

Create the feature serialize for bevy_color and remove serde::Serialize and Deserialize bound from trait StandardColor (or recreate if feature is enabled)

What alternative(s) have you considered?

Leave it as it is

Additional context

Notice that bevy_render depends on bevy_color, and as bevy_render doesn't flag serde by now, bevy_color can't too (unless of course we add the feature by default in bevy_render importing of bevy_color).

[alice-i-cecile]

We should add a serde flag for both crates, but there's no need to block. We can add it to bevy_color first, and just enable it during import initially.

[mghildiy]

I may give it a try. Please let me know.

[pablo-lua]

I may give it a try. Please let me know.

Feel free to solve this :D

[mghildiy]

So to summarize my understaning:

• bevy_color is a crate for which I need to create a new feature 'serialize'
• remove serde::Serialize and Deserialize from StandardColor(a traint defined in bevy_color)
• then use this new feature 'serialize' for StandardColor if enabled by user

Actually I am java pogrammer by experience and have just started learning Rust, so want to ensure things are clear to me.
Please bear with me.

[alice-i-cecile]

Yep: you'll also want to make sure that the serialize feature flag in bevy_color is toggled on if the corresponding feature on bevy is enabled.

[pablo-lua]

You can, too, have a look on prior work with similar tasks if that help: #11188
About the thing with StandardColor, that can be strange in design decision: We can't have type bounds being configurable by feature AFAIK, so you'll have to literally recreate the struct if feature is on
something like:

#[cfg(feature = "serialize")]
struct StandardColor 
where // . . .
{
 // . . .
}

#[cfg(not(feature = "serialize"))]
struct StandardColor 
where // . . .
{
// . . .
}

Thats probably the gist of it.

[alice-i-cecile]

I think we should just remove the Serialize + Deserialize bounds from StandardColor: I don't think the complexity is worth it for an internal helper.

[mghildiy]

PR

[mghildiy]

Build is failing due to some IO error. Is it down to code changes?