faer/mat/

matmut.rs

use super::{MatRef, *};
use crate::internal_prelude::*;
use crate::utils::bound::{Dim, Partition};
use crate::{Conj, ContiguousFwd, Idx, IdxInc};
use core::mem::MaybeUninit;

use equator::assert;
use faer_traits::ComplexField;
use generativity::Guard;
use linalg::zip::Last;
/// see [`super::MatMut`]
pub struct Mut<
	'a,
	T,
	Rows = usize,
	Cols = usize,
	RStride = isize,
	CStride = isize,
> {
	pub(super) imp: MatView<T, Rows, Cols, RStride, CStride>,
	pub(super) __marker: PhantomData<&'a mut T>,
}

/// write-only mutable matrix view over possibly uninitialized storage.
///
/// This type deliberately does not implement any operation that forms a
/// reference to `T`. It is used by overwrite-only kernels, which write through
/// the raw pointer and return an initialized view only after a full write.
pub struct UninitMut<
	'a,
	T,
	Rows = usize,
	Cols = usize,
	RStride = isize,
	CStride = isize,
> {
	pub(super) imp: MatView<MaybeUninit<T>, Rows, Cols, RStride, CStride>,
	pub(super) __marker: PhantomData<&'a mut MaybeUninit<T>>,
}

unsafe impl<T: Sync, Rows: Sync, Cols: Sync, RStride: Sync, CStride: Sync> Sync
	for UninitMut<'_, T, Rows, Cols, RStride, CStride>
{
}
unsafe impl<T: Send, Rows: Send, Cols: Send, RStride: Send, CStride: Send> Send
	for UninitMut<'_, T, Rows, Cols, RStride, CStride>
{
}

impl<'a, T, Rows: Shape, Cols: Shape, RStride: Stride, CStride: Stride>
	MatUninitMut<'a, T, Rows, Cols, RStride, CStride>
{
	/// creates a write-only matrix view from a raw pointer.
	///
	/// # safety
	/// the pointed-to memory must contain the complete matrix described by the
	/// dimensions and strides, be properly aligned for `MaybeUninit<T>`, and
	/// remain exclusively borrowed for `'a`. Matrix elements must not overlap
	/// each other. Unlike [`MatMut::from_raw_parts_mut`], the elements do not
	/// need to be initialized.
	#[inline]
	#[track_caller]
	pub const unsafe fn from_raw_parts_mut(
		ptr: *mut MaybeUninit<T>,
		nrows: Rows,
		ncols: Cols,
		row_stride: RStride,
		col_stride: CStride,
	) -> Self {
		generic::Mat(UninitMut {
			imp: MatView {
				ptr: NonNull::new_unchecked(ptr),
				nrows,
				ncols,
				row_stride,
				col_stride,
			},
			__marker: PhantomData,
		})
	}

	/// returns the raw pointer to the first matrix element.
	#[inline]
	pub fn as_ptr_mut(&self) -> *mut MaybeUninit<T> {
		self.imp.ptr.as_ptr()
	}

	/// returns the number of rows.
	#[inline]
	pub fn nrows(&self) -> Rows {
		self.imp.nrows
	}

	/// returns the number of columns.
	#[inline]
	pub fn ncols(&self) -> Cols {
		self.imp.ncols
	}

	/// returns the row stride in elements.
	#[inline]
	pub fn row_stride(&self) -> RStride {
		self.imp.row_stride
	}

	/// returns the column stride in elements.
	#[inline]
	pub fn col_stride(&self) -> CStride {
		self.imp.col_stride
	}

	/// converts this view to dynamic dimensions and strides.
	#[inline]
	pub fn as_dyn(self) -> MatUninitMut<'a, T, usize, usize, isize, isize> {
		let ptr = self.as_ptr_mut();
		let nrows = self.nrows().unbound();
		let ncols = self.ncols().unbound();
		let row_stride = self.row_stride().element_stride();
		let col_stride = self.col_stride().element_stride();
		unsafe {
			MatUninitMut::from_raw_parts_mut(
				ptr, nrows, ncols, row_stride, col_stride,
			)
		}
	}
}

impl<'a, T, Rows: Shape, Cols: Shape>
	MatUninitMut<'a, T, Rows, Cols, isize, isize>
{
	/// creates a column-major write-only view over a `MaybeUninit` slice.
	#[inline]
	#[track_caller]
	pub fn from_column_major_slice_mut(
		slice: &'a mut [MaybeUninit<T>],
		nrows: Rows,
		ncols: Cols,
	) -> Self {
		from_slice_assert(nrows.unbound(), ncols.unbound(), slice.len());
		unsafe {
			Self::from_raw_parts_mut(
				slice.as_mut_ptr(),
				nrows,
				ncols,
				1,
				nrows.unbound() as isize,
			)
		}
	}

	/// creates a row-major write-only view over a `MaybeUninit` slice.
	#[inline]
	#[track_caller]
	pub fn from_row_major_slice_mut(
		slice: &'a mut [MaybeUninit<T>],
		nrows: Rows,
		ncols: Cols,
	) -> Self {
		from_slice_assert(nrows.unbound(), ncols.unbound(), slice.len());
		unsafe {
			Self::from_raw_parts_mut(
				slice.as_mut_ptr(),
				nrows,
				ncols,
				ncols.unbound() as isize,
				1,
			)
		}
	}
}
#[repr(transparent)]
pub(crate) struct SyncCell<T>(T);
unsafe impl<T> Sync for SyncCell<T> {}
impl<'short, T, Rows: Copy, Cols: Copy, RStride: Copy, CStride: Copy>
	Reborrow<'short> for Mut<'_, T, Rows, Cols, RStride, CStride>
{
	type Target = Ref<'short, T, Rows, Cols, RStride, CStride>;

	#[inline]
	fn rb(&'short self) -> Self::Target {
		Ref {
			imp: self.imp,
			__marker: PhantomData,
		}
	}
}
impl<'short, T, Rows: Copy, Cols: Copy, RStride: Copy, CStride: Copy>
	ReborrowMut<'short> for Mut<'_, T, Rows, Cols, RStride, CStride>
{
	type Target = Mut<'short, T, Rows, Cols, RStride, CStride>;

	#[inline]
	fn rb_mut(&'short mut self) -> Self::Target {
		Mut {
			imp: self.imp,
			__marker: PhantomData,
		}
	}
}
impl<'a, T, Rows: Copy, Cols: Copy, RStride: Copy, CStride: Copy> IntoConst
	for Mut<'a, T, Rows, Cols, RStride, CStride>
{
	type Target = Ref<'a, T, Rows, Cols, RStride, CStride>;

	#[inline]
	fn into_const(self) -> Self::Target {
		Ref {
			imp: self.imp,
			__marker: PhantomData,
		}
	}
}
unsafe impl<T: Sync, Rows: Sync, Cols: Sync, RStride: Sync, CStride: Sync> Sync
	for Mut<'_, T, Rows, Cols, RStride, CStride>
{
}
unsafe impl<T: Send, Rows: Send, Cols: Send, RStride: Send, CStride: Send> Send
	for Mut<'_, T, Rows, Cols, RStride, CStride>
{
}
impl<'a, T> MatMut<'a, T> {
	/// equivalent to
	/// `MatMut::from_row_major_slice_mut(array.as_flattened_mut(), ROWS, COLS)`
	#[inline]
	pub fn from_row_major_array_mut<const ROWS: usize, const COLS: usize>(
		array: &'a mut [[T; COLS]; ROWS],
	) -> Self {
		unsafe {
			Self::from_raw_parts_mut(
				array as *mut _ as *mut T,
				ROWS,
				COLS,
				COLS as isize,
				1,
			)
		}
	}

	/// equivalent to
	/// `MatMut::from_column_major_slice_mut(array.as_flattened_mut(), ROWS,
	/// COLS)`
	#[inline]
	pub fn from_column_major_array_mut<const ROWS: usize, const COLS: usize>(
		array: &'a mut [[T; ROWS]; COLS],
	) -> Self {
		unsafe {
			Self::from_raw_parts_mut(
				array as *mut _ as *mut T,
				ROWS,
				COLS,
				1,
				ROWS as isize,
			)
		}
	}
}
impl<'a, T, Rows: Shape, Cols: Shape, RStride: Stride, CStride: Stride>
	MatMut<'a, T, Rows, Cols, RStride, CStride>
{
	/// creates a `MatMut` from a pointer to the matrix data, dimensions, and
	/// strides
	///
	/// the row (resp. column) stride is the offset from the memory address of a
	/// given matrix element at index `(row: i, col: j)`, to the memory address
	/// of the matrix element at index `(row: i + 1, col: 0)` (resp. `(row: 0,
	/// col: i + 1)`). this offset is specified in number of elements, not in
	/// bytes
	///
	/// # safety
	/// the behavior is undefined if any of the following conditions are
	/// violated:
	/// * for each matrix unit, the entire memory region addressed by the matrix
	///   must be contained
	/// within a single allocation, accessible in its entirety by the
	/// corresponding pointer in `ptr`
	/// * for each matrix unit, the corresponding pointer must be non null and
	///   properly aligned,
	/// even for a zero-sized matrix.
	/// * the values accessible by the matrix must be initialized at some point
	///   before they are read, or
	/// references to them are formed
	/// * no aliasing (including self aliasing) is allowed. in other words, none
	///   of the elements
	/// accessible by any matrix unit may be accessed for reads or writes by any
	/// other means for the duration of the lifetime `'a`. no two elements
	/// within a single matrix unit may point to the same address (such a thing
	/// can be achieved with a zero stride, for example), and no two
	/// matrix units may point to the same address
	///
	/// # example
	///
	/// ```
	/// use faer::{MatMut, mat};
	/// // row major matrix with 2 rows, 3 columns, with a column at the end that we want to skip.
	/// // the row stride is the pointer offset from the address of 1.0 to the address of 4.0,
	/// // which is 4
	/// // the column stride is the pointer offset from the address of 1.0 to the address of 2.0,
	/// // which is 1
	/// let mut data = [[1.0, 2.0, 3.0, f64::NAN], [4.0, 5.0, 6.0, f64::NAN]];
	/// let mut matrix =
	/// 	unsafe { MatMut::from_raw_parts_mut(data.as_mut_ptr() as *mut f64, 2, 3, 4, 1) };
	/// let expected = mat![[1.0, 2.0, 3.0], [4.0, 5.0, 6.0]];
	/// assert_eq!(expected.as_ref(), matrix);
	/// ```
	#[inline]
	#[track_caller]
	pub const unsafe fn from_raw_parts_mut(
		ptr: *mut T,
		nrows: Rows,
		ncols: Cols,
		row_stride: RStride,
		col_stride: CStride,
	) -> Self {
		MatMut {
			0: Mut {
				imp: MatView {
					ptr: NonNull::new_unchecked(ptr),
					nrows,
					ncols,
					row_stride,
					col_stride,
				},
				__marker: PhantomData,
			},
		}
	}

	/// returns a pointer to the matrix data
	#[inline]
	pub fn as_ptr(&self) -> *const T {
		self.imp.ptr.as_ptr()
	}

	/// returns the number of rows of the matrix
	#[inline]
	pub fn nrows(&self) -> Rows {
		self.imp.nrows
	}

	/// returns the number of columns of the matrix
	#[inline]
	pub fn ncols(&self) -> Cols {
		self.imp.ncols
	}

	/// returns the number of rows and columns of the matrix
	#[inline]
	pub fn shape(&self) -> (Rows, Cols) {
		(self.nrows(), self.ncols())
	}

	/// returns the row stride of the matrix, specified in number of elements,
	/// not in bytes
	#[inline]
	pub fn row_stride(&self) -> RStride {
		self.imp.row_stride
	}

	/// returns the column stride of the matrix, specified in number of
	/// elements, not in bytes
	#[inline]
	pub fn col_stride(&self) -> CStride {
		self.imp.col_stride
	}

	#[inline]
	pub fn map<U>(&self, f: impl Fn(&T) -> U) -> Mat<U, Rows, Cols> {
		self.rb().map(f)
	}

	#[inline]
	pub fn for_each(&self, f: impl Fn(&T)) {
		self.rb().for_each(f)
	}

	#[inline]
	pub fn map_mut<U>(
		&mut self,
		f: impl FnMut(&mut T) -> U,
	) -> Mat<U, Rows, Cols> {
		let mut f = f;
		zip!(self).map(|unzip!(x)| f(x))
	}

	#[inline]
	pub fn for_each_mut(&mut self, f: impl FnMut(&mut T)) {
		let mut f = f;
		zip!(self).for_each(|unzip!(x)| f(x))
	}

	/// returns a raw pointer to the element at the given index
	#[inline]
	pub fn ptr_at(&self, row: IdxInc<Rows>, col: IdxInc<Cols>) -> *const T {
		self.rb().ptr_at(row, col)
	}

	/// returns a raw pointer to the element at the given index, assuming the
	/// provided index is within the matrix bounds
	///
	/// # safety
	/// the behavior is undefined if any of the following conditions are
	/// violated:
	/// * `row < self.nrows()`
	/// * `col < self.ncols()`
	#[inline]
	#[track_caller]
	pub unsafe fn ptr_inbounds_at(
		&self,
		row: Idx<Rows>,
		col: Idx<Cols>,
	) -> *const T {
		self.rb().ptr_inbounds_at(row, col)
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::split_at`]
	pub fn split_at(
		self,
		row: IdxInc<Rows>,
		col: IdxInc<Cols>,
	) -> (
		MatRef<'a, T, usize, usize, RStride, CStride>,
		MatRef<'a, T, usize, usize, RStride, CStride>,
		MatRef<'a, T, usize, usize, RStride, CStride>,
		MatRef<'a, T, usize, usize, RStride, CStride>,
	) {
		self.into_const().split_at(row, col)
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::split_at_row`]
	pub fn split_at_row(
		self,
		row: IdxInc<Rows>,
	) -> (
		MatRef<'a, T, usize, Cols, RStride, CStride>,
		MatRef<'a, T, usize, Cols, RStride, CStride>,
	) {
		self.into_const().split_at_row(row)
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::split_at_col`]
	pub fn split_at_col(
		self,
		col: IdxInc<Cols>,
	) -> (
		MatRef<'a, T, Rows, usize, RStride, CStride>,
		MatRef<'a, T, Rows, usize, RStride, CStride>,
	) {
		self.into_const().split_at_col(col)
	}

	#[inline]
	/// see [`MatRef::transpose`]
	pub fn transpose(self) -> MatRef<'a, T, Cols, Rows, CStride, RStride> {
		MatRef {
			0: Ref {
				imp: MatView {
					ptr: self.imp.ptr,
					nrows: self.imp.ncols,
					ncols: self.imp.nrows,
					row_stride: self.imp.col_stride,
					col_stride: self.imp.row_stride,
				},
				__marker: PhantomData,
			},
		}
	}

	#[inline]
	/// see [`MatRef::conjugate`]
	pub fn conjugate(self) -> MatRef<'a, T::Conj, Rows, Cols, RStride, CStride>
	where
		T: Conjugate,
	{
		self.into_const().conjugate()
	}

	#[inline]
	/// see [`MatRef::canonical`]
	pub fn canonical(
		self,
	) -> MatRef<'a, T::Canonical, Rows, Cols, RStride, CStride>
	where
		T: Conjugate,
	{
		self.into_const().canonical()
	}

	#[inline]
	/// see [`MatRef::adjoint`]
	pub fn adjoint(self) -> MatRef<'a, T::Conj, Cols, Rows, CStride, RStride>
	where
		T: Conjugate,
	{
		self.into_const().adjoint()
	}

	#[inline]
	/// see [`MatRef::reverse_rows`]
	pub fn reverse_rows(
		self,
	) -> MatRef<'a, T, Rows, Cols, RStride::Rev, CStride> {
		self.into_const().reverse_rows()
	}

	#[inline]
	/// see [`MatRef::reverse_cols`]
	pub fn reverse_cols(
		self,
	) -> MatRef<'a, T, Rows, Cols, RStride, CStride::Rev> {
		self.into_const().reverse_cols()
	}

	#[inline]
	/// see [`MatRef::reverse_rows_and_cols`]
	pub fn reverse_rows_and_cols(
		self,
	) -> MatRef<'a, T, Rows, Cols, RStride::Rev, CStride::Rev> {
		self.into_const().reverse_rows_and_cols()
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::submatrix`]
	pub fn submatrix<V: Shape, H: Shape>(
		self,
		row_start: IdxInc<Rows>,
		col_start: IdxInc<Cols>,
		nrows: V,
		ncols: H,
	) -> MatRef<'a, T, V, H, RStride, CStride> {
		self.into_const()
			.submatrix(row_start, col_start, nrows, ncols)
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::subrows`]
	pub fn subrows<V: Shape>(
		self,
		row_start: IdxInc<Rows>,
		nrows: V,
	) -> MatRef<'a, T, V, Cols, RStride, CStride> {
		self.into_const().subrows(row_start, nrows)
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::subcols`]
	pub fn subcols<H: Shape>(
		self,
		col_start: IdxInc<Cols>,
		ncols: H,
	) -> MatRef<'a, T, Rows, H, RStride, CStride> {
		self.into_const().subcols(col_start, ncols)
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::as_shape`]
	pub fn as_shape<V: Shape, H: Shape>(
		self,
		nrows: V,
		ncols: H,
	) -> MatRef<'a, T, V, H, RStride, CStride> {
		self.into_const().as_shape(nrows, ncols)
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::as_row_shape`]
	pub fn as_row_shape<V: Shape>(
		self,
		nrows: V,
	) -> MatRef<'a, T, V, Cols, RStride, CStride> {
		self.into_const().as_row_shape(nrows)
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::as_col_shape`]
	pub fn as_col_shape<H: Shape>(
		self,
		ncols: H,
	) -> MatRef<'a, T, Rows, H, RStride, CStride> {
		self.into_const().as_col_shape(ncols)
	}

	#[inline]
	/// see [`MatRef::as_dyn_stride`]
	pub fn as_dyn_stride(self) -> MatRef<'a, T, Rows, Cols, isize, isize> {
		self.into_const().as_dyn_stride()
	}

	#[inline]
	/// see [`MatRef::as_dyn`]
	pub fn as_dyn(self) -> MatRef<'a, T, usize, usize, RStride, CStride> {
		self.into_const().as_dyn()
	}

	#[inline]
	/// see [`MatRef::as_dyn_rows`]
	pub fn as_dyn_rows(self) -> MatRef<'a, T, usize, Cols, RStride, CStride> {
		self.into_const().as_dyn_rows()
	}

	#[inline]
	/// see [`MatRef::as_dyn_cols`]
	pub fn as_dyn_cols(self) -> MatRef<'a, T, Rows, usize, RStride, CStride> {
		self.into_const().as_dyn_cols()
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::row`]
	pub fn row(self, i: Idx<Rows>) -> RowRef<'a, T, Cols, CStride> {
		self.into_const().row(i)
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::col`]
	pub fn col(self, j: Idx<Cols>) -> ColRef<'a, T, Rows, RStride> {
		self.into_const().col(j)
	}

	#[inline]
	/// see [`MatRef::col_iter`]
	pub fn col_iter(
		self,
	) -> impl 'a
	+ ExactSizeIterator
	+ DoubleEndedIterator<Item = ColRef<'a, T, Rows, RStride>>
	where
		Rows: 'a,
		Cols: 'a,
	{
		self.into_const().col_iter()
	}

	#[inline]
	/// see [`MatRef::row_iter`]
	pub fn row_iter(
		self,
	) -> impl 'a
	+ ExactSizeIterator
	+ DoubleEndedIterator<Item = RowRef<'a, T, Cols, CStride>>
	where
		Rows: 'a,
		Cols: 'a,
	{
		self.into_const().row_iter()
	}

	#[inline]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_col_iter`]
	pub fn par_col_iter(
		self,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = ColRef<'a, T, Rows, RStride>,
	>
	where
		T: Sync,
		Rows: 'a,
		Cols: 'a,
	{
		self.into_const().par_col_iter()
	}

	#[inline]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_row_iter`]
	pub fn par_row_iter(
		self,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = RowRef<'a, T, Cols, CStride>,
	>
	where
		T: Sync,
		Rows: 'a,
		Cols: 'a,
	{
		self.into_const().par_row_iter()
	}

	#[inline]
	#[track_caller]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_col_chunks`]
	pub fn par_col_chunks(
		self,
		chunk_size: usize,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = MatRef<'a, T, Rows, usize, RStride, CStride>,
	>
	where
		T: Sync,
		Rows: 'a,
		Cols: 'a,
	{
		self.into_const().par_col_chunks(chunk_size)
	}

	#[inline]
	#[track_caller]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_col_partition`]
	pub fn par_col_partition(
		self,
		count: usize,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = MatRef<'a, T, Rows, usize, RStride, CStride>,
	>
	where
		T: Sync,
		Rows: 'a,
		Cols: 'a,
	{
		self.into_const().par_col_partition(count)
	}

	#[inline]
	#[track_caller]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_row_chunks`]
	pub fn par_row_chunks(
		self,
		chunk_size: usize,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = MatRef<'a, T, usize, Cols, RStride, CStride>,
	>
	where
		T: Sync,
		Rows: 'a,
		Cols: 'a,
	{
		self.into_const().par_row_chunks(chunk_size)
	}

	#[inline]
	#[track_caller]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_row_partition`]
	pub fn par_row_partition(
		self,
		count: usize,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = MatRef<'a, T, usize, Cols, RStride, CStride>,
	>
	where
		T: Sync,
		Rows: 'a,
		Cols: 'a,
	{
		self.into_const().par_row_partition(count)
	}

	#[inline]
	/// see [`MatRef::try_as_col_major`]
	pub fn try_as_col_major(
		self,
	) -> Option<MatRef<'a, T, Rows, Cols, ContiguousFwd, CStride>> {
		self.into_const().try_as_col_major()
	}

	#[inline]
	/// see [`MatRef::try_as_row_major`]
	pub fn try_as_row_major(
		self,
	) -> Option<MatRef<'a, T, Rows, Cols, RStride, ContiguousFwd>> {
		self.into_const().try_as_row_major()
	}

	#[doc(hidden)]
	#[inline]
	pub unsafe fn const_cast(
		self,
	) -> MatMut<'a, T, Rows, Cols, RStride, CStride> {
		self
	}

	/// see [`MatRef::)]`]	#[doc(hidden)]
	#[inline]
	pub fn bind<'M, 'N>(
		self,
		row: Guard<'M>,
		col: Guard<'N>,
	) -> MatMut<'a, T, Dim<'M>, Dim<'N>, RStride, CStride> {
		unsafe {
			MatMut::from_raw_parts_mut(
				self.as_ptr_mut(),
				self.nrows().bind(row),
				self.ncols().bind(col),
				self.row_stride(),
				self.col_stride(),
			)
		}
	}

	#[doc(hidden)]
	#[inline]
	pub fn bind_r<'M>(
		self,
		row: Guard<'M>,
	) -> MatMut<'a, T, Dim<'M>, Cols, RStride, CStride> {
		unsafe {
			MatMut::from_raw_parts_mut(
				self.as_ptr_mut(),
				self.nrows().bind(row),
				self.ncols(),
				self.row_stride(),
				self.col_stride(),
			)
		}
	}

	#[doc(hidden)]
	#[inline]
	pub fn bind_c<'N>(
		self,
		col: Guard<'N>,
	) -> MatMut<'a, T, Rows, Dim<'N>, RStride, CStride> {
		unsafe {
			MatMut::from_raw_parts_mut(
				self.as_ptr_mut(),
				self.nrows(),
				self.ncols().bind(col),
				self.row_stride(),
				self.col_stride(),
			)
		}
	}

	#[track_caller]
	#[inline]
	/// see [`MatRef::get`]
	pub fn get<RowRange, ColRange>(
		self,
		row: RowRange,
		col: ColRange,
	) -> <MatRef<'a, T, Rows, Cols, RStride, CStride> as MatIndex<
		RowRange,
		ColRange,
	>>::Target
	where
		MatRef<'a, T, Rows, Cols, RStride, CStride>:
			MatIndex<RowRange, ColRange>,
	{
		<MatRef<'a, T, Rows, Cols, RStride, CStride> as MatIndex<
			RowRange,
			ColRange,
		>>::get(self.into_const(), row, col)
	}

	#[track_caller]
	#[inline]
	/// see [`MatRef::get_unchecked`]
	///
	/// # safety
	/// same as [`MatRef::get_unchecked`]
	pub unsafe fn get_unchecked<RowRange, ColRange>(
		self,
		row: RowRange,
		col: ColRange,
	) -> <MatRef<'a, T, Rows, Cols, RStride, CStride> as MatIndex<
		RowRange,
		ColRange,
	>>::Target
	where
		MatRef<'a, T, Rows, Cols, RStride, CStride>:
			MatIndex<RowRange, ColRange>,
	{
		unsafe {
			<MatRef<'a, T, Rows, Cols, RStride, CStride> as MatIndex<
				RowRange,
				ColRange,
			>>::get_unchecked(self.into_const(), row, col)
		}
	}

	/// see [`MatRef::get`]
	#[track_caller]
	#[inline]
	pub fn get_mut<RowRange, ColRange>(
		self,
		row: RowRange,
		col: ColRange,
	) -> <MatMut<'a, T, Rows, Cols, RStride, CStride> as MatIndex<
		RowRange,
		ColRange,
	>>::Target
	where
		MatMut<'a, T, Rows, Cols, RStride, CStride>:
			MatIndex<RowRange, ColRange>,
	{
		<MatMut<'a, T, Rows, Cols, RStride, CStride> as MatIndex<
			RowRange,
			ColRange,
		>>::get(self, row, col)
	}

	/// see [`MatRef::get_unchecked`]
	///
	/// # safety
	/// same as [`MatRef::get_unchecked`]
	#[track_caller]
	#[inline]
	pub unsafe fn get_mut_unchecked<RowRange, ColRange>(
		self,
		row: RowRange,
		col: ColRange,
	) -> <MatMut<'a, T, Rows, Cols, RStride, CStride> as MatIndex<
		RowRange,
		ColRange,
	>>::Target
	where
		MatMut<'a, T, Rows, Cols, RStride, CStride>:
			MatIndex<RowRange, ColRange>,
	{
		unsafe {
			<MatMut<'a, T, Rows, Cols, RStride, CStride> as MatIndex<
				RowRange,
				ColRange,
			>>::get_unchecked(self, row, col)
		}
	}
}
impl<
	T,
	Rows: Shape,
	Cols: Shape,
	RStride: Stride,
	CStride: Stride,
	Inner: for<'short> ReborrowMut<
			'short,
			Target = Mut<'short, T, Rows, Cols, RStride, CStride>,
		>,
> generic::Mat<Inner>
{
	/// returns a view over `self`
	#[inline]
	pub fn as_mut(&mut self) -> MatMut<'_, T, Rows, Cols, RStride, CStride> {
		self.rb_mut()
	}

	/// copies the lower triangular half of `other`, including the diagonal,
	/// into `self`
	#[inline]
	#[track_caller]
	pub fn copy_from_triangular_lower<RhsT: Conjugate<Canonical = T>>(
		&mut self,
		other: impl AsMatRef<T = RhsT, Rows = Rows, Cols = Cols>,
	) where
		T: ComplexField,
	{
		let other = other.as_mat_ref();
		let mut this = self.rb_mut();
		assert!(all(
			this.nrows() == other.nrows(),
			this.ncols() == other.ncols(),
		));
		let (m, n) = this.shape();
		make_guard!(M);
		make_guard!(N);
		let M = m.bind(M);
		let N = n.bind(N);
		let this = this.rb_mut().as_shape_mut(M, N).as_dyn_stride_mut();
		let other = other.as_shape(M, N);
		imp(this, other.canonical(), Conj::get::<RhsT>());
		pub fn imp<'M, 'N, T: ComplexField>(
			this: MatMut<'_, T, Dim<'M>, Dim<'N>>,
			other: MatRef<'_, T, Dim<'M>, Dim<'N>>,
			conj_: Conj,
		) {
			match conj_ {
				Conj::No => {
					zip!(this, other).for_each_triangular_lower(
						crate::linalg::zip::Diag::Include,
						|unzip!(dst, src)| *dst = src.copy(),
					);
				},
				Conj::Yes => {
					zip!(this, other).for_each_triangular_lower(
						crate::linalg::zip::Diag::Include,
						|unzip!(dst, src)| *dst = src.conj(),
					);
				},
			}
		}
	}

	/// copies the upper triangular half of `other`, including the diagonal,
	/// into `self`
	#[inline]
	#[track_caller]
	pub fn copy_from_triangular_upper<RhsT: Conjugate<Canonical = T>>(
		&mut self,
		other: impl AsMatRef<T = RhsT, Rows = Rows, Cols = Cols>,
	) where
		T: ComplexField,
	{
		(*self)
			.rb_mut()
			.transpose_mut()
			.copy_from_triangular_lower(other.as_mat_ref().transpose())
	}

	/// copies `other` into `self`
	#[inline]
	#[track_caller]
	pub fn copy_from<RhsT: Conjugate<Canonical = T>>(
		&mut self,
		other: impl AsMatRef<T = RhsT, Rows = Rows, Cols = Cols>,
	) where
		T: ComplexField,
	{
		let other = other.as_mat_ref();
		let mut this = self.rb_mut();
		assert!(all(
			this.nrows() == other.nrows(),
			this.ncols() == other.ncols(),
		));
		let (m, n) = this.shape();
		make_guard!(M);
		make_guard!(N);
		let M = m.bind(M);
		let N = n.bind(N);
		let this = this.rb_mut().as_shape_mut(M, N).as_dyn_stride_mut();
		let other = other.as_shape(M, N);
		imp(this, other.canonical(), Conj::get::<RhsT>());
		pub fn imp<'M, 'N, T: ComplexField>(
			this: MatMut<'_, T, Dim<'M>, Dim<'N>>,
			other: MatRef<'_, T, Dim<'M>, Dim<'N>>,
			conj_: Conj,
		) {
			match conj_ {
				Conj::No => {
					zip!(this, other)
						.for_each(|unzip!(dst, src)| *dst = src.copy());
				},
				Conj::Yes => {
					zip!(this, other)
						.for_each(|unzip!(dst, src)| *dst = src.conj());
				},
			}
		}
	}

	/// copies the lower triangular half of `other`, excluding the diagonal,
	/// into `self`
	#[inline]
	#[track_caller]
	pub fn copy_from_strict_triangular_lower<RhsT: Conjugate<Canonical = T>>(
		&mut self,
		other: impl AsMatRef<T = RhsT, Rows = Rows, Cols = Cols>,
	) where
		T: ComplexField,
	{
		let other = other.as_mat_ref();
		let mut this = self.rb_mut();
		assert!(all(
			this.nrows() == other.nrows(),
			this.ncols() == other.ncols(),
		));
		let (m, n) = this.shape();
		make_guard!(M);
		make_guard!(N);
		let M = m.bind(M);
		let N = n.bind(N);
		let this = this.rb_mut().as_shape_mut(M, N).as_dyn_stride_mut();
		let other = other.as_shape(M, N);
		imp(this, other.canonical(), Conj::get::<RhsT>());
		pub fn imp<'M, 'N, T: ComplexField>(
			this: MatMut<'_, T, Dim<'M>, Dim<'N>>,
			other: MatRef<'_, T, Dim<'M>, Dim<'N>>,
			conj_: Conj,
		) {
			match conj_ {
				Conj::No => {
					zip!(this, other).for_each_triangular_lower(
						crate::linalg::zip::Diag::Skip,
						|unzip!(dst, src)| *dst = src.copy(),
					);
				},
				Conj::Yes => {
					zip!(this, other).for_each_triangular_lower(
						crate::linalg::zip::Diag::Skip,
						|unzip!(dst, src)| *dst = src.conj(),
					);
				},
			}
		}
	}

	/// copies the upper triangular half of `other`, excluding the diagonal,
	/// into `self`
	#[inline]
	#[track_caller]
	pub fn copy_from_strict_triangular_upper<RhsT: Conjugate<Canonical = T>>(
		&mut self,
		other: impl AsMatRef<T = RhsT, Rows = Rows, Cols = Cols>,
	) where
		T: ComplexField,
	{
		(*self)
			.rb_mut()
			.transpose_mut()
			.copy_from_strict_triangular_lower(other.as_mat_ref().transpose())
	}

	/// fills all the elements of `self` with `value`
	#[inline]
	pub fn fill(&mut self, value: T)
	where
		T: Clone,
	{
		fn cloner<T: Clone>(value: T) -> impl for<'a> FnMut(Last<&'a mut T>) {
			#[inline]
			move |x| *x.0 = value.clone()
		}
		z!(self.rb_mut().as_dyn_mut()).for_each(cloner::<T>(value));
	}
}
impl<'a, T, Rows: Shape, Cols: Shape, RStride: Stride, CStride: Stride>
	MatMut<'a, T, Rows, Cols, RStride, CStride>
{
	#[inline]
	/// see [`MatRef::as_ptr`]
	pub fn as_ptr_mut(&self) -> *mut T {
		self.imp.ptr.as_ptr()
	}

	#[inline]
	/// see [`MatRef::ptr_at`]
	pub fn ptr_at_mut(&self, row: IdxInc<Rows>, col: IdxInc<Cols>) -> *mut T {
		self.rb().ptr_at(row, col) as *mut T
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::ptr_inbounds_at`]
	pub unsafe fn ptr_inbounds_at_mut(
		&self,
		row: Idx<Rows>,
		col: Idx<Cols>,
	) -> *mut T {
		self.rb().ptr_inbounds_at(row, col) as *mut T
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::split_at`]
	pub fn split_at_mut(
		self,
		row: IdxInc<Rows>,
		col: IdxInc<Cols>,
	) -> (
		MatMut<'a, T, usize, usize, RStride, CStride>,
		MatMut<'a, T, usize, usize, RStride, CStride>,
		MatMut<'a, T, usize, usize, RStride, CStride>,
		MatMut<'a, T, usize, usize, RStride, CStride>,
	) {
		let (a, b, c, d) = self.into_const().split_at(row, col);
		unsafe {
			(
				a.const_cast(),
				b.const_cast(),
				c.const_cast(),
				d.const_cast(),
			)
		}
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::split_at_row`]
	pub fn split_at_row_mut(
		self,
		row: IdxInc<Rows>,
	) -> (
		MatMut<'a, T, usize, Cols, RStride, CStride>,
		MatMut<'a, T, usize, Cols, RStride, CStride>,
	) {
		let (a, b) = self.into_const().split_at_row(row);
		unsafe { (a.const_cast(), b.const_cast()) }
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::split_at_col`]
	pub fn split_at_col_mut(
		self,
		col: IdxInc<Cols>,
	) -> (
		MatMut<'a, T, Rows, usize, RStride, CStride>,
		MatMut<'a, T, Rows, usize, RStride, CStride>,
	) {
		let (a, b) = self.into_const().split_at_col(col);
		unsafe { (a.const_cast(), b.const_cast()) }
	}

	#[inline]
	/// see [`MatRef::transpose`]
	pub fn transpose_mut(self) -> MatMut<'a, T, Cols, Rows, CStride, RStride> {
		MatMut {
			0: Mut {
				imp: MatView {
					ptr: self.imp.ptr,
					nrows: self.imp.ncols,
					ncols: self.imp.nrows,
					row_stride: self.imp.col_stride,
					col_stride: self.imp.row_stride,
				},
				__marker: PhantomData,
			},
		}
	}

	#[inline]
	/// see [`MatRef::conjugate`]
	pub fn conjugate_mut(
		self,
	) -> MatMut<'a, T::Conj, Rows, Cols, RStride, CStride>
	where
		T: Conjugate,
	{
		unsafe { self.into_const().conjugate().const_cast() }
	}

	#[inline]
	/// see [`MatRef::canonical`]
	pub fn canonical_mut(
		self,
	) -> MatMut<'a, T::Canonical, Rows, Cols, RStride, CStride>
	where
		T: Conjugate,
	{
		unsafe { self.into_const().canonical().const_cast() }
	}

	#[inline]
	/// see [`MatRef::adjoint`]
	pub fn adjoint_mut(
		self,
	) -> MatMut<'a, T::Conj, Cols, Rows, CStride, RStride>
	where
		T: Conjugate,
	{
		unsafe { self.into_const().adjoint().const_cast() }
	}

	#[inline]
	#[track_caller]
	pub(crate) fn at_mut(self, row: Idx<Rows>, col: Idx<Cols>) -> &'a mut T {
		assert!(all(row < self.nrows(), col < self.ncols()));
		unsafe { self.at_mut_unchecked(row, col) }
	}

	#[inline]
	#[track_caller]
	pub(crate) unsafe fn at_mut_unchecked(
		self,
		row: Idx<Rows>,
		col: Idx<Cols>,
	) -> &'a mut T {
		&mut *self.ptr_inbounds_at_mut(row, col)
	}

	#[inline]
	/// see [`MatRef::reverse_rows`]
	pub fn reverse_rows_mut(
		self,
	) -> MatMut<'a, T, Rows, Cols, RStride::Rev, CStride> {
		unsafe { self.into_const().reverse_rows().const_cast() }
	}

	#[inline]
	/// see [`MatRef::reverse_cols`]
	pub fn reverse_cols_mut(
		self,
	) -> MatMut<'a, T, Rows, Cols, RStride, CStride::Rev> {
		unsafe { self.into_const().reverse_cols().const_cast() }
	}

	#[inline]
	/// see [`MatRef::reverse_rows_and_cols`]
	pub fn reverse_rows_and_cols_mut(
		self,
	) -> MatMut<'a, T, Rows, Cols, RStride::Rev, CStride::Rev> {
		unsafe { self.into_const().reverse_rows_and_cols().const_cast() }
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::submatrix`]
	pub fn submatrix_mut<V: Shape, H: Shape>(
		self,
		row_start: IdxInc<Rows>,
		col_start: IdxInc<Cols>,
		nrows: V,
		ncols: H,
	) -> MatMut<'a, T, V, H, RStride, CStride> {
		unsafe {
			self.into_const()
				.submatrix(row_start, col_start, nrows, ncols)
				.const_cast()
		}
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::subrows`]
	pub fn subrows_mut<V: Shape>(
		self,
		row_start: IdxInc<Rows>,
		nrows: V,
	) -> MatMut<'a, T, V, Cols, RStride, CStride> {
		unsafe { self.into_const().subrows(row_start, nrows).const_cast() }
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::subcols`]
	pub fn subcols_mut<H: Shape>(
		self,
		col_start: IdxInc<Cols>,
		ncols: H,
	) -> MatMut<'a, T, Rows, H, RStride, CStride> {
		unsafe { self.into_const().subcols(col_start, ncols).const_cast() }
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::as_shape`]
	pub fn as_shape_mut<V: Shape, H: Shape>(
		self,
		nrows: V,
		ncols: H,
	) -> MatMut<'a, T, V, H, RStride, CStride> {
		unsafe { self.into_const().as_shape(nrows, ncols).const_cast() }
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::as_row_shape`]
	pub fn as_row_shape_mut<V: Shape>(
		self,
		nrows: V,
	) -> MatMut<'a, T, V, Cols, RStride, CStride> {
		unsafe { self.into_const().as_row_shape(nrows).const_cast() }
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::as_col_shape`]
	pub fn as_col_shape_mut<H: Shape>(
		self,
		ncols: H,
	) -> MatMut<'a, T, Rows, H, RStride, CStride> {
		unsafe { self.into_const().as_col_shape(ncols).const_cast() }
	}

	#[inline]
	/// see [`MatRef::as_dyn_stride`]
	pub fn as_dyn_stride_mut(self) -> MatMut<'a, T, Rows, Cols, isize, isize> {
		unsafe { self.into_const().as_dyn_stride().const_cast() }
	}

	#[inline]
	/// see [`MatRef::as_dyn`]
	pub fn as_dyn_mut(self) -> MatMut<'a, T, usize, usize, RStride, CStride> {
		unsafe { self.into_const().as_dyn().const_cast() }
	}

	#[inline]
	/// see [`MatRef::as_dyn_rows`]
	pub fn as_dyn_rows_mut(
		self,
	) -> MatMut<'a, T, usize, Cols, RStride, CStride> {
		unsafe { self.into_const().as_dyn_rows().const_cast() }
	}

	#[inline]
	/// see [`MatRef::as_dyn_cols`]
	pub fn as_dyn_cols_mut(
		self,
	) -> MatMut<'a, T, Rows, usize, RStride, CStride> {
		unsafe { self.into_const().as_dyn_cols().const_cast() }
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::row`]
	pub fn row_mut(self, i: Idx<Rows>) -> RowMut<'a, T, Cols, CStride> {
		unsafe { self.into_const().row(i).const_cast() }
	}

	#[inline]
	#[track_caller]
	/// see [`MatRef::col`]
	pub fn col_mut(self, j: Idx<Cols>) -> ColMut<'a, T, Rows, RStride> {
		unsafe { self.into_const().col(j).const_cast() }
	}

	#[inline]
	/// see [`MatRef::col_iter`]
	pub fn col_iter_mut(
		self,
	) -> impl 'a
	+ ExactSizeIterator
	+ DoubleEndedIterator<Item = ColMut<'a, T, Rows, RStride>>
	where
		Rows: 'a,
		Cols: 'a,
	{
		self.into_const()
			.col_iter()
			.map(|x| unsafe { x.const_cast() })
	}

	#[inline]
	/// see [`MatRef::row_iter`]
	pub fn row_iter_mut(
		self,
	) -> impl 'a
	+ ExactSizeIterator
	+ DoubleEndedIterator<Item = RowMut<'a, T, Cols, CStride>>
	where
		Rows: 'a,
		Cols: 'a,
	{
		self.into_const()
			.row_iter()
			.map(|x| unsafe { x.const_cast() })
	}

	#[inline]
	pub(crate) unsafe fn as_type<U>(
		self,
	) -> MatMut<'a, U, Rows, Cols, RStride, CStride> {
		MatMut::from_raw_parts_mut(
			self.as_ptr_mut() as *mut U,
			self.nrows(),
			self.ncols(),
			self.row_stride(),
			self.col_stride(),
		)
	}

	#[inline]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_col_iter`]
	pub fn par_col_iter_mut(
		self,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = ColMut<'a, T, Rows, RStride>,
	>
	where
		T: Send,
		Rows: 'a,
		Cols: 'a,
	{
		use rayon::prelude::*;
		unsafe {
			self.as_type::<SyncCell<T>>()
				.into_const()
				.par_col_iter()
				.map(|x| x.const_cast())
				.map(|x| x.as_type())
		}
	}

	#[inline]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_row_iter`]
	pub fn par_row_iter_mut(
		self,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = RowMut<'a, T, Cols, CStride>,
	>
	where
		T: Send,
		Rows: 'a,
		Cols: 'a,
	{
		use rayon::prelude::*;
		unsafe {
			self.as_type::<SyncCell<T>>()
				.into_const()
				.par_row_iter()
				.map(|x| x.const_cast())
				.map(|x| x.as_type())
		}
	}

	#[inline]
	#[track_caller]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_col_chunks`]
	pub fn par_col_chunks_mut(
		self,
		chunk_size: usize,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = MatMut<'a, T, Rows, usize, RStride, CStride>,
	>
	where
		T: Send,
		Rows: 'a,
		Cols: 'a,
	{
		use rayon::prelude::*;
		unsafe {
			self.as_type::<SyncCell<T>>()
				.into_const()
				.par_col_chunks(chunk_size)
				.map(|x| x.const_cast())
				.map(|x| x.as_type())
		}
	}

	#[inline]
	#[track_caller]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_col_partition`]
	pub fn par_col_partition_mut(
		self,
		count: usize,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = MatMut<'a, T, Rows, usize, RStride, CStride>,
	>
	where
		T: Send,
		Rows: 'a,
		Cols: 'a,
	{
		use rayon::prelude::*;
		unsafe {
			self.as_type::<SyncCell<T>>()
				.into_const()
				.par_col_partition(count)
				.map(|x| x.const_cast())
				.map(|x| x.as_type())
		}
	}

	#[inline]
	#[track_caller]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_row_chunks`]
	pub fn par_row_chunks_mut(
		self,
		chunk_size: usize,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = MatMut<'a, T, usize, Cols, RStride, CStride>,
	>
	where
		T: Send,
		Rows: 'a,
		Cols: 'a,
	{
		use rayon::prelude::*;
		unsafe {
			self.as_type::<SyncCell<T>>()
				.into_const()
				.par_row_chunks(chunk_size)
				.map(|x| x.const_cast())
				.map(|x| x.as_type())
		}
	}

	#[inline]
	#[track_caller]
	#[cfg(feature = "rayon")]
	/// see [`MatRef::par_row_partition`]
	pub fn par_row_partition_mut(
		self,
		count: usize,
	) -> impl 'a
	+ rayon::iter::IndexedParallelIterator<
		Item = MatMut<'a, T, usize, Cols, RStride, CStride>,
	>
	where
		T: Send,
		Rows: 'a,
		Cols: 'a,
	{
		use rayon::prelude::*;
		unsafe {
			self.as_type::<SyncCell<T>>()
				.into_const()
				.par_row_partition(count)
				.map(|x| x.const_cast())
				.map(|x| x.as_type())
		}
	}

	#[inline]
	/// see [`MatRef::split_first_row`]
	pub fn split_first_row_mut(
		self,
	) -> Option<(
		RowMut<'a, T, Cols, CStride>,
		MatMut<'a, T, usize, Cols, RStride, CStride>,
	)> {
		if let Some(i0) = self.nrows().idx_inc(1) {
			let (head, tail) = self.split_at_row_mut(i0);
			Some((head.row_mut(0), tail))
		} else {
			None
		}
	}

	#[inline]
	/// see [`MatRef::split_first_col`]
	pub fn split_first_col_mut(
		self,
	) -> Option<(
		ColMut<'a, T, Rows, RStride>,
		MatMut<'a, T, Rows, usize, RStride, CStride>,
	)> {
		if let Some(i0) = self.ncols().idx_inc(1) {
			let (head, tail) = self.split_at_col_mut(i0);
			Some((head.col_mut(0), tail))
		} else {
			None
		}
	}

	#[inline]
	/// see [`MatRef::split_last_row`]
	pub fn split_last_row_mut(
		self,
	) -> Option<(
		RowMut<'a, T, Cols, CStride>,
		MatMut<'a, T, usize, Cols, RStride, CStride>,
	)> {
		if self.nrows().unbound() > 0 {
			let i0 = self.nrows().checked_idx_inc(self.nrows().unbound() - 1);
			let (head, tail) = self.split_at_row_mut(i0);
			Some((tail.row_mut(0), head))
		} else {
			None
		}
	}

	#[inline]
	/// see [`MatRef::split_last_col`]
	pub fn split_last_col_mut(
		self,
	) -> Option<(
		ColMut<'a, T, Rows, RStride>,
		MatMut<'a, T, Rows, usize, RStride, CStride>,
	)> {
		if self.ncols().unbound() > 0 {
			let i0 = self.ncols().checked_idx_inc(self.ncols().unbound() - 1);
			let (head, tail) = self.split_at_col_mut(i0);
			Some((tail.col_mut(0), head))
		} else {
			None
		}
	}

	#[inline]
	/// see [`MatRef::split_first_row`]
	pub fn split_first_row(
		self,
	) -> Option<(
		RowRef<'a, T, Cols, CStride>,
		MatRef<'a, T, usize, Cols, RStride, CStride>,
	)> {
		self.into_const().split_first_row()
	}

	#[inline]
	/// see [`MatRef::split_first_col`]
	pub fn split_first_col(
		self,
	) -> Option<(
		ColRef<'a, T, Rows, RStride>,
		MatRef<'a, T, Rows, usize, RStride, CStride>,
	)> {
		self.into_const().split_first_col()
	}

	#[inline]
	/// see [`MatRef::split_last_row`]
	pub fn split_last_row(
		self,
	) -> Option<(
		RowRef<'a, T, Cols, CStride>,
		MatRef<'a, T, usize, Cols, RStride, CStride>,
	)> {
		self.into_const().split_last_row()
	}

	#[inline]
	/// see [`MatRef::split_last_col`]
	pub fn split_last_col(
		self,
	) -> Option<(
		ColRef<'a, T, Rows, RStride>,
		MatRef<'a, T, Rows, usize, RStride, CStride>,
	)> {
		self.into_const().split_last_col()
	}

	#[inline]
	/// see [`MatRef::try_as_col_major`]
	pub fn try_as_col_major_mut(
		self,
	) -> Option<MatMut<'a, T, Rows, Cols, ContiguousFwd, CStride>> {
		self.into_const()
			.try_as_col_major()
			.map(|x| unsafe { x.const_cast() })
	}

	#[inline]
	/// see [`MatRef::try_as_row_major`]
	pub fn try_as_row_major_mut(
		self,
	) -> Option<MatMut<'a, T, Rows, Cols, RStride, ContiguousFwd>> {
		self.into_const()
			.try_as_row_major()
			.map(|x| unsafe { x.const_cast() })
	}

	/// returns two views over the given columns
	///
	/// # panics
	/// panics if `i0 == i1`
	#[inline]
	#[track_caller]
	pub fn two_cols_mut(
		self,
		i0: Idx<Cols>,
		i1: Idx<Cols>,
	) -> (ColMut<'a, T, Rows, RStride>, ColMut<'a, T, Rows, RStride>) {
		assert!(i0 != i1);
		let this = self.into_const();
		unsafe { (this.col(i0).const_cast(), this.col(i1).const_cast()) }
	}

	/// returns two views over the given rows
	///
	/// # panics
	/// panics if `i0 == i1`
	#[inline]
	#[track_caller]
	pub fn two_rows_mut(
		self,
		i0: Idx<Rows>,
		i1: Idx<Rows>,
	) -> (RowMut<'a, T, Cols, CStride>, RowMut<'a, T, Cols, CStride>) {
		assert!(i0 != i1);
		let this = self.into_const();
		unsafe { (this.row(i0).const_cast(), this.row(i1).const_cast()) }
	}

	#[inline]
	pub(crate) fn __at_mut(self, (i, j): (Idx<Rows>, Idx<Cols>)) -> &'a mut T {
		self.at_mut(i, j)
	}
}
impl<'a, T, Rows: Shape, Cols: Shape> MatMut<'a, T, Rows, Cols> {
	/// creates a `MatMut` from slice views over the matrix data, and the matrix
	/// dimensions. the data is interpreted in a column-major format, so that
	/// the first chunk of `nrows` values from the slices goes in the first
	/// column of the matrix, the second chunk of `nrows` values goes in the
	/// second column, and so on
	///
	/// # panics
	/// the function panics if any of the following conditions are violated:
	/// * `nrows * ncols == slice.len()`
	///
	/// # example
	/// ```
	/// use faer::{MatMut, mat};
	/// let mut slice = [1.0, 2.0, 3.0, 4.0, 5.0, 6.0_f64];
	/// let view = MatMut::from_column_major_slice_mut(&mut slice, 3, 2);
	/// let expected = mat![[1.0, 4.0], [2.0, 5.0], [3.0, 6.0]];
	/// assert_eq!(expected, view);
	/// ```
	#[inline]
	#[track_caller]
	pub fn from_column_major_slice_mut(
		slice: &'a mut [T],
		nrows: Rows,
		ncols: Cols,
	) -> Self
	where
		T: Sized,
	{
		from_slice_assert(nrows.unbound(), ncols.unbound(), slice.len());
		unsafe {
			Self::from_raw_parts_mut(
				slice.as_mut_ptr(),
				nrows,
				ncols,
				1,
				nrows.unbound() as isize,
			)
		}
	}

	/// creates a `MatMut` from slice views over the matrix data, and the matrix
	/// dimensions. the data is interpreted in a column-major format, where the
	/// beginnings of two consecutive columns are separated by `col_stride`
	/// elements.
	#[inline]
	#[track_caller]
	pub fn from_column_major_slice_with_stride_mut(
		slice: &'a mut [T],
		nrows: Rows,
		ncols: Cols,
		col_stride: usize,
	) -> Self
	where
		T: Sized,
	{
		from_strided_column_major_slice_mut_assert(
			nrows.unbound(),
			ncols.unbound(),
			col_stride,
			slice.len(),
		);
		unsafe {
			Self::from_raw_parts_mut(
				slice.as_mut_ptr(),
				nrows,
				ncols,
				1,
				col_stride as isize,
			)
		}
	}

	/// creates a `MatMut` from slice views over the matrix data, and the matrix
	/// dimensions. the data is interpreted in a row-major format, so that the
	/// first chunk of `ncols` values from the slices goes in the first column
	/// of the matrix, the second chunk of `ncols` values goes in the second
	/// column, and so on
	///
	/// # panics
	/// the function panics if any of the following conditions are violated:
	/// * `nrows * ncols == slice.len()`
	///
	/// # example
	/// ```
	/// use faer::{MatMut, mat};
	/// let mut slice = [1.0, 2.0, 3.0, 4.0, 5.0, 6.0_f64];
	/// let view = MatMut::from_row_major_slice_mut(&mut slice, 3, 2);
	/// let expected = mat![[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]];
	/// assert_eq!(expected, view);
	/// ```
	#[inline]
	#[track_caller]
	pub fn from_row_major_slice_mut(
		slice: &'a mut [T],
		nrows: Rows,
		ncols: Cols,
	) -> Self
	where
		T: Sized,
	{
		MatMut::from_column_major_slice_mut(slice, ncols, nrows).transpose_mut()
	}

	/// creates a `MatMut` from slice views over the matrix data, and the matrix
	/// dimensions. the data is interpreted in a row-major format, where the
	/// beginnings of two consecutive rows are separated by `row_stride`
	/// elements.
	#[inline]
	#[track_caller]
	pub fn from_row_major_slice_with_stride_mut(
		slice: &'a mut [T],
		nrows: Rows,
		ncols: Cols,
		row_stride: usize,
	) -> Self
	where
		T: Sized,
	{
		from_strided_row_major_slice_mut_assert(
			nrows.unbound(),
			ncols.unbound(),
			row_stride,
			slice.len(),
		);
		unsafe {
			Self::from_raw_parts_mut(
				slice.as_mut_ptr(),
				nrows,
				ncols,
				row_stride as isize,
				1,
			)
		}
	}
}
impl<'ROWS, 'COLS, 'a, T, RStride: Stride, CStride: Stride>
	MatMut<'a, T, Dim<'ROWS>, Dim<'COLS>, RStride, CStride>
{
	#[doc(hidden)]
	#[inline]
	pub fn split_with_mut<'TOP, 'BOT, 'LEFT, 'RIGHT>(
		self,
		row: Partition<'TOP, 'BOT, 'ROWS>,
		col: Partition<'LEFT, 'RIGHT, 'COLS>,
	) -> (
		MatMut<'a, T, Dim<'TOP>, Dim<'LEFT>, RStride, CStride>,
		MatMut<'a, T, Dim<'TOP>, Dim<'RIGHT>, RStride, CStride>,
		MatMut<'a, T, Dim<'BOT>, Dim<'LEFT>, RStride, CStride>,
		MatMut<'a, T, Dim<'BOT>, Dim<'RIGHT>, RStride, CStride>,
	) {
		let (a, b, c, d) = self.split_at_mut(row.midpoint(), col.midpoint());
		(
			a.as_shape_mut(row.head, col.head),
			b.as_shape_mut(row.head, col.tail),
			c.as_shape_mut(row.tail, col.head),
			d.as_shape_mut(row.tail, col.tail),
		)
	}
}
impl<'ROWS, 'a, T, Cols: Shape, RStride: Stride, CStride: Stride>
	MatMut<'a, T, Dim<'ROWS>, Cols, RStride, CStride>
{
	#[doc(hidden)]
	#[inline]
	pub fn split_rows_with_mut<'TOP, 'BOT>(
		self,
		row: Partition<'TOP, 'BOT, 'ROWS>,
	) -> (
		MatMut<'a, T, Dim<'TOP>, Cols, RStride, CStride>,
		MatMut<'a, T, Dim<'BOT>, Cols, RStride, CStride>,
	) {
		let (a, b) = self.split_at_row_mut(row.midpoint());
		(a.as_row_shape_mut(row.head), b.as_row_shape_mut(row.tail))
	}
}
impl<'COLS, 'a, T, Rows: Shape, RStride: Stride, CStride: Stride>
	MatMut<'a, T, Rows, Dim<'COLS>, RStride, CStride>
{
	#[doc(hidden)]
	#[inline]
	pub fn split_cols_with_mut<'LEFT, 'RIGHT>(
		self,
		col: Partition<'LEFT, 'RIGHT, 'COLS>,
	) -> (
		MatMut<'a, T, Rows, Dim<'LEFT>, RStride, CStride>,
		MatMut<'a, T, Rows, Dim<'RIGHT>, RStride, CStride>,
	) {
		let (a, b) = self.split_at_col_mut(col.midpoint());
		(a.as_col_shape_mut(col.head), b.as_col_shape_mut(col.tail))
	}
}
impl<'ROWS, 'COLS, 'a, T, RStride: Stride, CStride: Stride>
	MatMut<'a, T, Dim<'ROWS>, Dim<'COLS>, RStride, CStride>
{
	#[doc(hidden)]
	#[inline]
	pub fn split_with<'TOP, 'BOT, 'LEFT, 'RIGHT>(
		self,
		row: Partition<'TOP, 'BOT, 'ROWS>,
		col: Partition<'LEFT, 'RIGHT, 'COLS>,
	) -> (
		MatRef<'a, T, Dim<'TOP>, Dim<'LEFT>, RStride, CStride>,
		MatRef<'a, T, Dim<'TOP>, Dim<'RIGHT>, RStride, CStride>,
		MatRef<'a, T, Dim<'BOT>, Dim<'LEFT>, RStride, CStride>,
		MatRef<'a, T, Dim<'BOT>, Dim<'RIGHT>, RStride, CStride>,
	) {
		let (a, b, c, d) = self.split_at(row.midpoint(), col.midpoint());
		(
			a.as_shape(row.head, col.head),
			b.as_shape(row.head, col.tail),
			c.as_shape(row.tail, col.head),
			d.as_shape(row.tail, col.tail),
		)
	}
}
impl<'ROWS, 'a, T, Cols: Shape, RStride: Stride, CStride: Stride>
	MatMut<'a, T, Dim<'ROWS>, Cols, RStride, CStride>
{
	#[doc(hidden)]
	#[inline]
	pub fn split_rows_with<'TOP, 'BOT>(
		self,
		row: Partition<'TOP, 'BOT, 'ROWS>,
	) -> (
		MatRef<'a, T, Dim<'TOP>, Cols, RStride, CStride>,
		MatRef<'a, T, Dim<'BOT>, Cols, RStride, CStride>,
	) {
		let (a, b) = self.split_at_row(row.midpoint());
		(a.as_row_shape(row.head), b.as_row_shape(row.tail))
	}
}
impl<'COLS, 'a, T, Rows: Shape, RStride: Stride, CStride: Stride>
	MatMut<'a, T, Rows, Dim<'COLS>, RStride, CStride>
{
	#[doc(hidden)]
	#[inline]
	pub fn split_cols_with<'LEFT, 'RIGHT>(
		self,
		col: Partition<'LEFT, 'RIGHT, 'COLS>,
	) -> (
		MatRef<'a, T, Rows, Dim<'LEFT>, RStride, CStride>,
		MatRef<'a, T, Rows, Dim<'RIGHT>, RStride, CStride>,
	) {
		let (a, b) = self.split_at_col(col.midpoint());
		(a.as_col_shape(col.head), b.as_col_shape(col.tail))
	}
}
impl<'a, T, Dim: Shape, RStride: Stride, CStride: Stride>
	MatMut<'a, T, Dim, Dim, RStride, CStride>
{
	/// see [`MatRef::diagonal`]
	#[inline]
	pub fn diagonal(self) -> DiagRef<'a, T, Dim, isize> {
		self.into_const().diagonal()
	}
}
impl<'a, T, Dim: Shape, RStride: Stride, CStride: Stride>
	MatMut<'a, T, Dim, Dim, RStride, CStride>
{
	/// see [`MatRef::diagonal`]
	#[inline]
	pub fn diagonal_mut(self) -> DiagMut<'a, T, Dim, isize> {
		unsafe {
			self.into_const()
				.diagonal()
				.column_vector()
				.const_cast()
				.as_diagonal_mut()
		}
	}
}
impl<
	'a,
	T: core::fmt::Debug,
	Rows: Shape,
	Cols: Shape,
	RStride: Stride,
	CStride: Stride,
> core::fmt::Debug for Mut<'a, T, Rows, Cols, RStride, CStride>
{
	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
		self.rb().fmt(f)
	}
}
impl<'a, T, Rows: Shape, Cols: Shape> MatMut<'a, T, Rows, Cols>
where
	T: RealField,
{
	/// see [MatRef::min]
	pub fn min(self) -> Option<T> {
		MatRef::internal_min(self.rb().as_dyn())
	}

	/// see [MatRef::min]
	pub fn max(self) -> Option<T> {
		MatRef::internal_max(self.rb().as_dyn())
	}
}
#[track_caller]
#[inline]
fn from_strided_column_major_slice_mut_assert(
	nrows: usize,
	ncols: usize,
	col_stride: usize,
	len: usize,
) {
	if nrows > 0 && ncols > 0 {
		let last = usize::checked_mul(col_stride, ncols - 1)
			.and_then(|last_col| last_col.checked_add(nrows - 1));
		let Some(last) = last else {
			panic!("address computation of the last matrix element overflowed");
		};
		assert!(all(col_stride >= nrows, last < len));
	}
}
#[track_caller]
#[inline]
fn from_strided_row_major_slice_mut_assert(
	nrows: usize,
	ncols: usize,
	row_stride: usize,
	len: usize,
) {
	if nrows > 0 && ncols > 0 {
		let last = usize::checked_mul(row_stride, nrows - 1)
			.and_then(|last_row| last_row.checked_add(ncols - 1));
		let Some(last) = last else {
			panic!("address computation of the last matrix element overflowed");
		};
		assert!(all(row_stride >= ncols, last < len));
	}
}
#[cfg(test)]
mod tests {
	use super::*;
	#[test]
	fn test_min() {
		let mut m = mat![[1.0, 5.0, 3.0], [4.0, 2.0, 9.0], [7.0, 8.0, 6.0],];
		assert_eq!(m.as_mut().min(), Some(1.0));
		let mut empty: Mat<f64> = Mat::new();
		assert_eq!(empty.as_mut().min(), None);
	}
	#[test]
	fn test_max() {
		let mut m = mat![[1.0, 5.0, 3.0], [4.0, 2.0, 9.0], [7.0, 8.0, 6.0],];
		assert_eq!(m.as_mut().max(), Some(9.0));
		let mut empty: Mat<f64> = Mat::new();
		assert_eq!(empty.as_mut().max(), None);
	}
	#[test]
	fn codeberg_305() {
		const PAD: f64 = -42.0;
		let mut slice = [0.0, 1.0, 2.0, PAD, 3.0, 4.0, 5.0, PAD, PAD, PAD];
		{
			let mut mat_view = MatMut::from_row_major_slice_with_stride_mut(
				&mut slice, 2, 3, 4,
			);
			assert_eq!(mat![[0.0, 1.0, 2.0], [3.0, 4.0, 5.0]], mat_view);
			mat_view[(1, 2)] = 99.0;
		}
		assert_eq!(slice, [0.0, 1.0, 2.0, PAD, 3.0, 4.0, 99.0, PAD, PAD, PAD]);
	}
}