I've lived with this warning for a long time because I didn't really understand
it.
```
warning: `chessfriend_core` (lib) generated 1 warning (run `cargo fix --lib -p chessfriend_core` to apply 1 suggestion)
warning: creating a shared reference to mutable static is discouraged
--> bitboard/src/library.rs:66:9
```
I was able to fix this by creating a new type with a single OnceLock attribute.
The OnceLock acts as a cell, making it mutable, even if self is not. So, you can
declare the MoveLibraryWrapper non-mutable static, but still initialize the
library inside the Cell.
- Add chessfriend_core::Color::NUM
- All the library getters can be const.
- Use the constants from the core library to define the length of the slices in
the Library struct.
- Add allow(dead_code) to LIGHT_SQUARES and DARK_SQUARES. These aren't used yet
but I have a feeling they'll come in handy.
- Add some separators to long numeric literals.
- Lightly reformat BitBoard -> Bitboard in the module documentation
- Implement BitBoard::is_populated(), the opposite of ::is_empty()
- Write a bit of documentation for the BitBoard Library and for some methods on BitBoard
- Mark a few methods as const
Use u64::MIN and u64::MAX to define the empty and full bitboards
Write From<Square> as `1u64 << sq as u32`
Write a doc test for BitBoard::is_single_square()
Make library::RANKS and library::FILES pub(crate) instead of pub(super)
This trait declares ray_to_square() which should return a BitBoard representing
a ray from a Square to another Square. The ray should include the target Square.
PlacedPiece implements this trait.
Add two small BitBoard slices that represent kingside and queenside squares per
color.
Add doc comments to DARK_SQUARES and LIGHT_SQUARES.
Add getters on BitBoard for getting a boardside bitboard.
Clean up imports. Import the whole library module and refer to library things in
BitBoard by path.
This enables a bunch of clean up! Remove the MoveGenerationParameters and MoveList
types from move_generator::pawn.
Implement BitBoard::pawn_pushes to look up pawn pushes by square and color.
