Define copy! for Symmetric and Hermitian

Author: ararslan

base/linalg/symmetric.jl

@@ -133,6 +133,8 @@ convert{T}(::Type{AbstractMatrix{T}}, A::Hermitian) = Hermitian(convert(Abstract
 
 copy{T,S}(A::Symmetric{T,S}) = (B = copy(A.data); Symmetric{T,typeof(B)}(B,A.uplo))
 copy{T,S}(A::Hermitian{T,S}) = (B = copy(A.data); Hermitian{T,typeof(B)}(B,A.uplo))
+copy!(dest::Symmetric, src::Symmetric) = Symmetric(copy!(dest.data, src.data), Symbol(src.uplo))
+copy!(dest::Hermitian, src::Hermitian) = Hermitian(copy!(dest.data, src.data), Symbol(src.uplo))
 ishermitian(A::Hermitian) = true
 ishermitian{T<:Real,S}(A::Symmetric{T,S}) = true
 ishermitian{T<:Complex,S}(A::Symmetric{T,S}) = all(imag(A.data) .== 0)

base/linalg/uniformscaling.jl

@@ -56,6 +56,10 @@ ishermitian(J::UniformScaling) = isreal(J.λ)
 (-)(B::BitArray{2}, J::UniformScaling)      = Array(B) - J
 (-)(J::UniformScaling, B::BitArray{2})      = J - Array(B)
 
+for t in (:Symmetric, :Hermitian), op in (:+, :-)
+    @eval ($op)(X::$t, J::UniformScaling) = ($t)(($op)(X.data, J), Symbol(X.uplo))
+end
+
 for (t1, t2) in ((:UnitUpperTriangular, :UpperTriangular),
                  (:UnitLowerTriangular, :LowerTriangular))
     for op in (:+,:-)

test/linalg/symmetric.jl

@@ -250,3 +250,17 @@ let a = randn(2,2)
     cc = copy(c)
     @test conj!(c) == conj(Array(c))
 end
+
+# 19225
+let X = sparse([1 -1; -1 1])
+    for T in (Symmetric, Hermitian)
+        Y = T(X)
+        _Y = similar(Y)
+        copy!(_Y, Y)
+        @test _Y == Y
+        @test Y + I == T(sparse([2 -1; -1 2]))
+        @test Y - I == T(sparse([0 -1; -1 0]))
+    end
+    @test_throws ArgumentError Hermitian(X) + 2im*I
+    @test_throws ArgumentError Hermitian(X) - 2im*I
+end