#[reflect(Trait)] on a generic struct can't conditionally reflect depending on generic parameters

[aristaeus]

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

Typically a derive macro such as PartialEq is clever enough to only work when a struct's generic parameters implement PartialEq, by adding trait bounds to the impl. It would be nice to do something similar with Reflect:

#[derive(Reflect, PartialEq)]
#[reflect(PartialEq)] // error
struct Foo<T> {
    foo: T,
}

Looking at the proc macro it's not immediately obvious to me how do this.

What solution would you like?

Some way of telling the Reflect macro to only reflect traits when the generic type implements them.

Additional context

This came up in #13348 (comment) When resolved, open a trivial PR to add the PartialEq reflection.