From 37ac53eb13644bbd0d68a977262b30a25240e92d Mon Sep 17 00:00:00 2001
From: Kristoffer <kcarlsson89@gmail.com>
Date: Mon, 6 May 2024 12:08:05 +0200
Subject: [PATCH] Revert "Add `_unsetindex!` methods for `SubArray`s and
 `CartesianIndex`es (#53383)"

This reverts commit 1a9040908b9bb89927b2d318da3f9fe1e457abea.

(cherry picked from commit f8a74967188d26abd2916d0f21365f14fdfc2bba)
---
 base/abstractarray.jl    | 15 +-------------
 base/array.jl            |  7 +------
 base/multidimensional.jl |  6 ------
 base/subarray.jl         | 19 -----------------
 test/subarray.jl         | 44 ----------------------------------------
 5 files changed, 2 insertions(+), 89 deletions(-)

diff --git a/base/abstractarray.jl b/base/abstractarray.jl
index 4bcc763d66a199..56390de1eb5d3f 100644
--- a/base/abstractarray.jl
+++ b/base/abstractarray.jl
@@ -1452,20 +1452,7 @@ function _setindex!(::IndexCartesian, A::AbstractArray, v, I::Vararg{Int,M}) whe
     r
 end
 
-function _unsetindex!(A::AbstractArray, i::Integer...)
-    @_propagate_inbounds_meta
-    _unsetindex!(A, map(to_index, i)...)
-end
-
-function _unsetindex!(A::AbstractArray{T}, i::Int...) where T
-    # this provides a fallback method which is a no-op if the element is already unassigned
-    # such that copying into an uninitialized object generally always will work,
-    # even if the specific custom array type has not implemented `_unsetindex!`
-    @inline
-    @boundscheck checkbounds(A, i...)
-    allocatedinline(T) || @inbounds(!isassigned(A, i...)) || throw(MethodError(_unsetindex!, (A, i...)))
-    return A
-end
+_unsetindex!(A::AbstractArray, i::Integer) = _unsetindex!(A, to_index(i))
 
 """
     parent(A)
diff --git a/base/array.jl b/base/array.jl
index 83ca35714c2449..19d79479bef39a 100644
--- a/base/array.jl
+++ b/base/array.jl
@@ -219,12 +219,7 @@ function _unsetindex!(A::Array, i::Int)
     @inbounds _unsetindex!(GenericMemoryRef(A.ref, i))
     return A
 end
-function _unsetindex!(A::Array, i::Int...)
-    @inline
-    @boundscheck checkbounds(A, i...)
-    @inbounds _unsetindex!(A, _to_linear_index(A, i...))
-    return A
-end
+
 
 # TODO: deprecate this (aligned_sizeof and/or elsize and/or sizeof(Some{T}) are more correct)
 elsize(::Type{A}) where {T,A<:Array{T}} = aligned_sizeof(T)
diff --git a/base/multidimensional.jl b/base/multidimensional.jl
index fe29e5c1d8e5f7..146f8c160e8e9d 100644
--- a/base/multidimensional.jl
+++ b/base/multidimensional.jl
@@ -1610,12 +1610,6 @@ end
     end
 end
 
-# _unsetindex
-@propagate_inbounds function Base._unsetindex!(A::AbstractArray, i::CartesianIndex)
-    Base._unsetindex!(A, to_indices(A, (i,))...)
-    return A
-end
-
 ## permutedims
 
 ## Permute array dims ##
diff --git a/base/subarray.jl b/base/subarray.jl
index 759b564aade17d..b67b917a478b3c 100644
--- a/base/subarray.jl
+++ b/base/subarray.jl
@@ -413,25 +413,6 @@ function isassigned(V::FastSubArray{<:Any, 1}, i::Int)
     r
 end
 
-function _unsetindex!(V::FastSubArray, i::Int)
-    @inline
-    @boundscheck checkbounds(V, i)
-    @inbounds _unsetindex!(V.parent, _reindexlinear(V, i))
-    return V
-end
-function _unsetindex!(V::FastSubArray{<:Any,1}, i::Int)
-    @inline
-    @boundscheck checkbounds(V, i)
-    @inbounds _unsetindex!(V.parent, _reindexlinear(V, i))
-    return V
-end
-function _unsetindex!(V::SubArray{T,N}, i::Vararg{Int,N}) where {T,N}
-    @inline
-    @boundscheck checkbounds(V, i...)
-    @inbounds _unsetindex!(V.parent, reindex(V.indices, i)...)
-    return V
-end
-
 IndexStyle(::Type{<:FastSubArray}) = IndexLinear()
 IndexStyle(::Type{<:SubArray}) = IndexCartesian()
 
diff --git a/test/subarray.jl b/test/subarray.jl
index 337e666da918c8..9fd59ef5a41562 100644
--- a/test/subarray.jl
+++ b/test/subarray.jl
@@ -1074,48 +1074,4 @@ end
         @test !isassigned(v, 1, 2) # inbounds but not assigned
         @test !isassigned(v, 3, 3) # out-of-bounds
     end
-
-    @testset "_unsetindex!" begin
-        function test_unsetindex(A, B)
-            copyto!(A, B)
-            for i in eachindex(A)
-                @test !isassigned(A, i)
-            end
-            inds = eachindex(A)
-            @test_throws BoundsError Base._unsetindex!(A, last(inds) + oneunit(eltype(inds)))
-        end
-        @testset "dest IndexLinear, src IndexLinear" begin
-            for p in (fill(BigInt(2)), BigInt[1, 2], BigInt[1 2; 3 4])
-                A = view(copy(p), ntuple(_->:, ndims(p))...)
-                B = view(similar(A), ntuple(_->:, ndims(p))...)
-                test_unsetindex(A, B)
-                test_unsetindex(p, B)
-            end
-        end
-
-        @testset "dest IndexLinear, src IndexCartesian" begin
-            for p in (fill(BigInt(2)), BigInt[1, 2], BigInt[1 2; 3 4])
-                A = view(copy(p), ntuple(_->:, ndims(p))...)
-                B = view(similar(A), axes(A)...)
-                test_unsetindex(A, B)
-                test_unsetindex(p, B)
-            end
-        end
-
-        @testset "dest IndexCartesian, src IndexLinear" begin
-            for p in (fill(BigInt(2)), BigInt[1, 2], BigInt[1 2; 3 4])
-                A = view(p, axes(p)...)
-                B = similar(A)
-                test_unsetindex(A, B)
-            end
-        end
-
-        @testset "dest IndexCartesian, src IndexCartesian" begin
-            for p in (fill(BigInt(2)), BigInt[1, 2], BigInt[1 2; 3 4])
-                A = view(p, axes(p)...)
-                B = view(similar(A), axes(A)...)
-                test_unsetindex(A, B)
-            end
-        end
-    end
 end