t4a-faer 0.27.1

use crate::assert;
use crate::internal_prelude::*;
use alloc::vec;
use dyn_stack::MemBuffer;
pub fn determinant<T: ComplexField>(
	mat: MatRef<'_, T>,
	mut par: Par<'_>,
) -> T::Canonical {
	assert!(mat.nrows() == mat.ncols());
	let par_shape = par.shape();
	let (m, n) = mat.shape();
	let mut row_perm_fwd = vec![0usize; m];
	let mut row_perm_bwd = vec![0usize; m];
	let mut factors = mat.to_owned();
	let count =
		linalg::lu::partial_pivoting::factor::lu_in_place(
			factors.as_mat_mut(),
			&mut row_perm_fwd,
			&mut row_perm_bwd,
			par.reborrow(),
			MemStack::new(&mut MemBuffer::new(
				linalg::lu::partial_pivoting::factor::lu_in_place_scratch::<
					usize,
					T,
				>(m, n, par_shape, default()),
			)),
			default(),
		)
		.0
		.transposition_count;
	let mut det = one::<T>();
	for i in 0..factors.nrows() {
		det *= &factors[(i, i)];
	}
	if count % 2 == 0 { det } else { -det }
}