Attribute Macro queryable

#[queryable]

When added to a trait declaration, generates the impls required to use that trait in queries.

Poor use cases

You should avoid using trait queries for very simple cases that can be solved with more direct solutions.

One naive use would be querying for a trait that looks something like:

trait Person {
    fn name(&self) -> &str;
}

A far better way of expressing this would be to store the name in a separate component and query for that directly, making Person a simple marker component.

Trait queries are often the most obvious solution to a problem, but not always the best one. For examples of strong real-world use-cases, check out the RFC for trait queries in bevy: https://github.com/bevyengine/rfcs/pull/39.

Note

This will add the trait bound 'static to the trait and all of its type parameters.

You may opt out of this by using the form #[queryable(no_bounds)], but you will have to add the bounds yourself to make it compile.