Christian Hughes f87b9fe20c Turn apply_deferred into a ZST System (#16642) ... # Objective - Required by #16622 due to differing implementations of `System` by `FunctionSystem` and `ExclusiveFunctionSystem`. - Optimize the memory usage of instances of `apply_deferred` in system schedules. ## Solution By changing `apply_deferred` from being an ordinary system that ends up as an `ExclusiveFunctionSystem`, and instead into a ZST struct that implements `System` manually, we save ~320 bytes per instance of `apply_deferred` in any schedule. ## Testing - All current tests pass. --- ## Migration Guide - If you were previously calling the special `apply_deferred` system via `apply_deferred(world)`, don't.		2024-12-05 18:14:05 +00:00
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executor	Turn apply_deferred into a ZST System (#16642)	2024-12-05 18:14:05 +00:00
graph	Turn apply_deferred into a ZST System (#16642)	2024-12-05 18:14:05 +00:00
condition.rs	Add core and alloc over std Lints (#15281)	2024-09-27 00:59:59 +00:00
config.rs	Turn apply_deferred into a ZST System (#16642)	2024-12-05 18:14:05 +00:00
mod.rs	Remove petgraph from bevy_ecs (#15519)	2024-12-03 20:01:55 +00:00
schedule.rs	Turn apply_deferred into a ZST System (#16642)	2024-12-05 18:14:05 +00:00
set.rs	Add core and alloc over std Lints (#15281)	2024-09-27 00:59:59 +00:00
stepping.rs	Remove thiserror from bevy_ecs (#15774)	2024-10-09 14:20:58 +00:00