# Objective
- Fixes#6370
- Closes#6581
## Solution
- Added the following lints to the workspace:
- `std_instead_of_core`
- `std_instead_of_alloc`
- `alloc_instead_of_core`
- Used `cargo +nightly fmt` with [item level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Item%5C%3A)
to split all `use` statements into single items.
- Used `cargo clippy --workspace --all-targets --all-features --fix
--allow-dirty` to _attempt_ to resolve the new linting issues, and
intervened where the lint was unable to resolve the issue automatically
(usually due to needing an `extern crate alloc;` statement in a crate
root).
- Manually removed certain uses of `std` where negative feature gating
prevented `--all-features` from finding the offending uses.
- Used `cargo +nightly fmt` with [crate level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Crate%5C%3A)
to re-merge all `use` statements matching Bevy's previous styling.
- Manually fixed cases where the `fmt` tool could not re-merge `use`
statements due to conditional compilation attributes.
## Testing
- Ran CI locally
## Migration Guide
The MSRV is now 1.81. Please update to this version or higher.
## Notes
- This is a _massive_ change to try and push through, which is why I've
outlined the semi-automatic steps I used to create this PR, in case this
fails and someone else tries again in the future.
- Making this change has no impact on user code, but does mean Bevy
contributors will be warned to use `core` and `alloc` instead of `std`
where possible.
- This lint is a critical first step towards investigating `no_std`
options for Bevy.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
- Fixes#14974
## Solution
- Replace all* instances of `NonZero*` with `NonZero<*>`
## Testing
- CI passed locally.
---
## Notes
Within the `bevy_reflect` implementations for `std` types,
`impl_reflect_value!()` will continue to use the type aliases instead,
as it inappropriately parses the concrete type parameter as a generic
argument. If the `ZeroablePrimitive` trait was stable, or the macro
could be modified to accept a finite list of types, then we could fully
migrate.
# Objective
The purpose of this PR is to begin putting together a unified identifier
structure that can be used by entities and later components (as
entities) as well as relationship pairs for relations, to enable all of
these to be able to use the same storages. For the moment, to keep
things small and focused, only `Entity` is being changed to make use of
the new `Identifier` type, keeping `Entity`'s API and
serialization/deserialization the same. Further changes are for
follow-up PRs.
## Solution
`Identifier` is a wrapper around `u64` split into two `u32` segments
with the idea of being generalised to not impose restrictions on
variants. That is for `Entity` to do. Instead, it is a general API for
taking bits to then merge and map into a `u64` integer. It exposes
low/high methods to return the two value portions as `u32` integers,
with then the MSB masked for usage as a type flag, enabling entity kind
discrimination and future activation/deactivation semantics.
The layout in this PR for `Identifier` is described as below, going from
MSB -> LSB.
```
|F| High value | Low value |
|_|_______________________________|________________________________|
|1| 31 | 32 |
F = Bit Flags
```
The high component in this implementation has only 31 bits, but that
still leaves 2^31 or 2,147,483,648 values that can be stored still, more
than enough for any generation/relation kinds/etc usage. The low part is
a full 32-bit index. The flags allow for 1 bit to be used for
entity/pair discrimination, as these have different usages for the
low/high portions of the `Identifier`. More bits can be reserved for
more variants or activation/deactivation purposes, but this currently
has no use in bevy.
More bits could be reserved for future features at the cost of bits for
the high component, so how much to reserve is up for discussion. Also,
naming of the struct and methods are also subject to further
bikeshedding and feedback.
Also, because IDs can have different variants, I wonder if
`Entity::from_bits` needs to return a `Result` instead of potentially
panicking on receiving an invalid ID.
PR is provided as an early WIP to obtain feedback and notes on whether
this approach is viable.
---
## Changelog
### Added
New `Identifier` struct for unifying IDs.
### Changed
`Entity` changed to use new `Identifier`/`IdentifierMask` as the
underlying ID logic.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: vero <email@atlasdostal.com>
