From 3355e946e817e24464ba7d0d1619507bd08e09e1 Mon Sep 17 00:00:00 2001
From: Daniel Karrasch <Daniel.Karrasch@posteo.de>
Date: Wed, 6 Sep 2023 17:41:01 +0200
Subject: [PATCH 1/2] Introduce cholesky and qr hooks for wrapped sparse
 matrices

---
 stdlib/LinearAlgebra/src/cholesky.jl | 10 ++++++----
 stdlib/LinearAlgebra/src/qr.jl       |  5 ++++-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/stdlib/LinearAlgebra/src/cholesky.jl b/stdlib/LinearAlgebra/src/cholesky.jl
index 82f138db7d7b9..04ef0ebc9f67f 100644
--- a/stdlib/LinearAlgebra/src/cholesky.jl
+++ b/stdlib/LinearAlgebra/src/cholesky.jl
@@ -399,14 +399,16 @@ true
 ```
 """
 cholesky(A::AbstractMatrix, ::NoPivot=NoPivot(); check::Bool = true) =
-    cholesky!(cholcopy(A); check)
+    _cholesky(cholcopy(A); check)
 @deprecate cholesky(A::Union{StridedMatrix,RealHermSymComplexHerm{<:Real,<:StridedMatrix}}, ::Val{false}; check::Bool = true) cholesky(A, NoPivot(); check) false
 
 function cholesky(A::AbstractMatrix{Float16}, ::NoPivot=NoPivot(); check::Bool = true)
-    X = cholesky!(cholcopy(A); check = check)
+    X = _cholesky(cholcopy(A); check = check)
     return Cholesky{Float16}(X)
 end
 @deprecate cholesky(A::Union{StridedMatrix{Float16},RealHermSymComplexHerm{Float16,<:StridedMatrix}}, ::Val{false}; check::Bool = true) cholesky(A, NoPivot(); check) false
+# allow packages like SparseArrays.jl to hook into here and redirect to out-of-place `cholesky`
+_cholesky(A::AbstractMatrix, args...; kwargs) = cholesky!(A, args...; kwargs...)
 
 ## With pivoting
 """
@@ -465,11 +467,11 @@ true
 ```
 """
 cholesky(A::AbstractMatrix, ::RowMaximum; tol = 0.0, check::Bool = true) =
-    cholesky!(cholcopy(A), RowMaximum(); tol, check)
+    _cholesky(cholcopy(A), RowMaximum(); tol, check)
 @deprecate cholesky(A::Union{StridedMatrix,RealHermSymComplexHerm{<:Real,<:StridedMatrix}}, ::Val{true}; tol = 0.0, check::Bool = true) cholesky(A, RowMaximum(); tol, check) false
 
 function cholesky(A::AbstractMatrix{Float16}, ::RowMaximum; tol = 0.0, check::Bool = true)
-    X = cholesky!(cholcopy(A), RowMaximum(); tol, check)
+    X = _cholesky(cholcopy(A), RowMaximum(); tol, check)
     return CholeskyPivoted{Float16}(X)
 end
 
diff --git a/stdlib/LinearAlgebra/src/qr.jl b/stdlib/LinearAlgebra/src/qr.jl
index fe40fec78e801..563fa7c049c65 100644
--- a/stdlib/LinearAlgebra/src/qr.jl
+++ b/stdlib/LinearAlgebra/src/qr.jl
@@ -417,12 +417,15 @@ true
 function qr(A::AbstractMatrix{T}, arg...; kwargs...) where T
     require_one_based_indexing(A)
     AA = copy_similar(A, _qreltype(T))
-    return qr!(AA, arg...; kwargs...)
+    return _qr(AA, arg...; kwargs...)
 end
 # TODO: remove in Julia v2.0
 @deprecate qr(A::AbstractMatrix, ::Val{false}; kwargs...) qr(A, NoPivot(); kwargs...)
 @deprecate qr(A::AbstractMatrix, ::Val{true}; kwargs...)  qr(A, ColumnNorm(); kwargs...)
 
+# allow packages like SparseArrays.jl to hook into here and redirect to out-of-place `qr`
+_qr(A::AbstractMatrix, args...; kwargs...) = qr!(A, args...; kwargs...)
+
 qr(x::Number) = qr(fill(x,1,1))
 function qr(v::AbstractVector)
     require_one_based_indexing(v)

From 4b55c4af8e9ef97fc09bee41e60827789c7ce419 Mon Sep 17 00:00:00 2001
From: Daniel Karrasch <Daniel.Karrasch@posteo.de>
Date: Thu, 7 Sep 2023 13:24:01 +0200
Subject: [PATCH 2/2] fix signature typo

---
 stdlib/LinearAlgebra/src/cholesky.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/stdlib/LinearAlgebra/src/cholesky.jl b/stdlib/LinearAlgebra/src/cholesky.jl
index 04ef0ebc9f67f..528eca5c3d8a3 100644
--- a/stdlib/LinearAlgebra/src/cholesky.jl
+++ b/stdlib/LinearAlgebra/src/cholesky.jl
@@ -408,7 +408,7 @@ function cholesky(A::AbstractMatrix{Float16}, ::NoPivot=NoPivot(); check::Bool =
 end
 @deprecate cholesky(A::Union{StridedMatrix{Float16},RealHermSymComplexHerm{Float16,<:StridedMatrix}}, ::Val{false}; check::Bool = true) cholesky(A, NoPivot(); check) false
 # allow packages like SparseArrays.jl to hook into here and redirect to out-of-place `cholesky`
-_cholesky(A::AbstractMatrix, args...; kwargs) = cholesky!(A, args...; kwargs...)
+_cholesky(A::AbstractMatrix, args...; kwargs...) = cholesky!(A, args...; kwargs...)
 
 ## With pivoting
 """