Chris Russell 9e2bd8ac18 Generic SystemParam impls for Option and Result (#18766) ... # Objective Provide a generic `impl SystemParam for Option<P>` that uses system parameter validation. This immediately gives useful impls for params like `EventReader` and `GizmosState` that are defined in terms of `Res`. It also allows third-party system parameters to be usable with `Option`, which was previously impossible due to orphan rules. Note that this is a behavior change for `Option<Single>`. It currently fails validation if there are multiple matching entities, but with this change it will pass validation and produce `None`. Also provide an impl for `Result<P, SystemParamValidationError>`. This allows systems to inspect the error if necessary, either for bubbling it up or for checking the `skipped` flag. Fixes #12634 Fixes #14949 Related to #18516 ## Solution Add generic `SystemParam` impls for `Option` and `Result`, and remove the impls for specific types. Update documentation and `fallible_params` example with the new semantics for `Option<Single>`.		2025-05-07 18:20:08 +00:00
..
change_detection.rs	Rename track_change_detection flag to track_location (#17075)	2025-01-01 18:43:47 +00:00
component_hooks.rs	Preserve spawned RelationshipTarget order and other improvements (#17858)	2025-03-05 22:18:57 +00:00
custom_query_param.rs	Prefer Display over Debug (#16112)	2024-12-27 00:40:06 +00:00
custom_schedule.rs	Simpler lint fixes: makes ci lints work but disables a lint for now (#15376)	2024-09-24 11:42:59 +00:00
dynamic.rs	Remove deprecated component_reads_and_writes (#16348)	2025-03-04 08:22:29 +00:00
ecs_guide.rs	Adopt consistent FooSystems naming convention for system sets (#18900)	2025-05-06 15:18:03 +00:00
entity_disabling.rs	Make Query::single (and friends) return a Result (#18082)	2025-03-02 19:51:56 +00:00
error_handling.rs	Use Display instead of Debug in the default error handler (#18629)	2025-03-31 18:28:19 +00:00
event.rs	Renamed EventWriter::send methods to write. (#17977)	2025-02-23 21:18:52 +00:00
fallible_params.rs	Generic SystemParam impls for Option and Result (#18766)	2025-05-07 18:20:08 +00:00
fixed_timestep.rs	aligning public apis of Time,Timer and Stopwatch (#15962)	2024-10-16 21:09:32 +00:00
generic_system.rs	Relationships (non-fragmenting, one-to-many) (#17398)	2025-01-18 22:20:30 +00:00
hierarchy.rs	Add an example teaching users about custom relationships (#17443)	2025-01-20 23:17:38 +00:00
immutable_components.rs	Rename bevy_platform_support to bevy_platform (#18813)	2025-04-11 23:13:28 +00:00
iter_combinations.rs	aligning public apis of Time,Timer and Stopwatch (#15962)	2024-10-16 21:09:32 +00:00
nondeterministic_system_order.rs
observer_propagation.rs	Improve derive(Event) and simplify macro code (#18083)	2025-03-07 02:01:23 +00:00
observers.rs	Rename bevy_platform_support to bevy_platform (#18813)	2025-04-11 23:13:28 +00:00
one_shot_systems.rs	Merge Style properties into Node. Use ComputedNode for computed properties. (#15975)	2024-10-18 22:25:33 +00:00
parallel_query.rs	Make Query::single (and friends) return a Result (#18082)	2025-03-02 19:51:56 +00:00
relationships.rs	Change with_related to work with a Bundle and added with_relationships method (#18699)	2025-04-09 02:34:49 +00:00
removal_detection.rs	Rename trigger.entity() to trigger.target() (#16716)	2024-12-08 21:55:09 +00:00
run_conditions.rs	aligning public apis of Time,Timer and Stopwatch (#15962)	2024-10-16 21:09:32 +00:00
send_and_receive_events.rs	Renamed EventWriter::send methods to write. (#17977)	2025-02-23 21:18:52 +00:00
startup_system.rs
state_scoped.rs	Rename StateScoped to DespawnOnExitState and add DespawnOnEnterState (#18818)	2025-05-06 00:37:04 +00:00
system_closure.rs	Prefer Display over Debug (#16112)	2024-12-27 00:40:06 +00:00
system_param.rs
system_piping.rs	Fix a few typos (#17292)	2025-01-10 22:48:30 +00:00
system_stepping.rs	Remove stepping from default features (#12847)	2024-04-03 19:16:02 +00:00