Initial commit.

Can build the final binary.

tools/ddw3-bytes/src/array_split.rs

@@ -0,0 +1,111 @@
+//! Array splitting
+
+// TODO: Add back a `PhantomData` field for when splitting nothing once
+//       rust-analyzer doesn't crap itself with it
+
+/// Splits a byte array reference into several smaller byte arrays references,
+/// or even single byte references.
+pub macro array_split
+	(
+		$arr:expr,
+		$(
+			$name:ident :
+
+			$( [$arr_size:expr]    )?
+			$(  $val_size:literal  )?
+
+		),* $(,)?
+	) {{
+		// Struct holding all fields
+		#[derive(Clone, Copy, Debug)]
+		struct Fields<'a, T> {
+			$(
+				pub $name:
+
+				$( &'a [T; $arr_size], )?
+				$( &'a T, #[cfg(invalid)] __field: [u8; $val_size], )?
+			)*
+		}
+
+		// Get everything from `array_refs`
+		#[allow(
+			clippy::used_underscore_binding,
+			clippy::ptr_offset_with_cast,
+			clippy::indexing_slicing,
+		)]
+		let (
+			$(
+				$name
+			),*
+		) = $crate::arrayref::array_refs!(
+			$arr,
+			$(
+				$( $arr_size )?
+				$( $val_size )?
+			),*
+		);
+
+		// And return the fields
+		Fields {
+			$(
+				$name
+				$( : &( $name[$val_size - $val_size] ) )?
+				,
+			)*
+		}
+	}}
+
+/// Splits a byte array mutable reference into several smaller byte arrays references,
+/// or even single byte references.
+#[allow(clippy::module_name_repetitions)] // `_mut` version should be in the same module
+pub macro array_split_mut(
+		$arr:expr,
+		$(
+			$name:ident :
+
+			$( [$arr_size:expr]    )?
+			$(  $val_size:literal  )?
+
+		),* $(,)?
+	) {{
+		// Struct holding all fields
+		#[derive(Debug)]
+		struct Fields<'a, T> {
+			$(
+				pub $name:
+
+				$( &'a mut [T; $arr_size], )?
+				// Note: This `cfg` is simply done so that `__field` never appears.
+				//       The `__field` serves to identify when this part should be written.
+				$( &'a mut T, #[cfg(invalid)] __field: [u8; $val_size], )?
+			)*
+		}
+
+		// Get everything from `mut_array_refs`
+		#[allow(
+			clippy::used_underscore_binding,
+			clippy::ptr_offset_with_cast,
+			clippy::indexing_slicing,
+		)]
+		let (
+			$(
+				$name
+			),*
+		) = $crate::arrayref::mut_array_refs!(
+			$arr,
+			$(
+				$( $arr_size )?
+				$( $val_size )?
+			),*
+		);
+
+		// And return the fields
+		Fields {
+			$(
+				$name
+				// Note: This serves to turn a `&mut [u8; 1]` into a `&mut u8`.
+				$( : &mut ( $name[$val_size - $val_size] ) )?
+				,
+			)*
+		}
+	}}