Function sprs_ldl::ldl_symbolic

pub fn ldl_symbolic<N, I, PStorage>(
    mat: CsMatViewI<'_, N, I>, 
    perm: &Permutation<I, PStorage>, 
    l_colptr: &mut [I], 
    parents: ParentsViewMut<'_>, 
    l_nz: &mut [I], 
    flag_workspace: &mut [I], 
    check_symmetry: SymmetryCheck
) where
    N: Clone + Copy + PartialEq,
    I: SpIndex,
    PStorage: Deref<Target = [I]>, 

Perform a symbolic LDLT decomposition of a symmetric sparse matrix