Specialize setindex! with BandIndex for adj/trans

Author: jishnub

src/adjtrans.jl

@@ -357,6 +357,11 @@ IndexStyle(::Type{<:AdjOrTransAbsVec}) = IndexLinear()
     require_one_based_indexing(A)
     wrapperop(A)(A.parent[BandIndex(-b.band, b.index)])::T
 end
+@propagate_inbounds function setindex!(A::AdjOrTransAbsMat, x, b::BandIndex)
+    require_one_based_indexing(A)
+    setindex!(A.parent, _wrapperop(A)(x), BandIndex(-b.band, b.index))
+    return A
+end
 
 # conversion of underlying storage
 convert(::Type{Adjoint{T,S}}, A::Adjoint) where {T,S} = Adjoint{T,S}(convert(S, A.parent))::Adjoint{T,S}

test/adjtrans.jl

@@ -751,13 +751,17 @@ end
 
 @testset "band indexing" begin
     n = 3
-    A = UnitUpperTriangular(reshape(1:n^2, n, n))
+    A = UnitUpperTriangular(Matrix(reshape(1:n^2, n, n)))
     @testset "every index" begin
-        Aadj = A'
+        Aadj = Adjoint(A)
         for k in -(n-1):n-1
             di = diagind(Aadj, k, IndexStyle(Aadj))
             for (i,d) in enumerate(di)
                 @test Aadj[LinearAlgebra.BandIndex(k,i)] == Aadj[d]
+                if k < 0 # the adjoint is a unit lower triangular
+                    Aadj[LinearAlgebra.BandIndex(k,i)] = n^2 + i
+                    @test Aadj[d] == n^2 + i
+                end
             end
         end
     end