Revert some of 0.9.4 (#71)

* Relax to_vec(::Number)

* Reverts adjoint / transpose to_vec

* Bumps version

Author: willtebbutt

Project.toml

@@ -1,6 +1,6 @@
 name = "FiniteDifferences"
 uuid = "26cc04aa-876d-5657-8c51-4c34ba976000"
-version = "0.9.4"
+version = "0.9.5"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

src/to_vec.jl

@@ -6,7 +6,7 @@ transformation.
 """
 function to_vec(x::Number)
     function Number_from_vec(x_vec)
-        return oftype(x, first(x_vec))
+        return first(x_vec)
     end
     return [x], Number_from_vec
 end
@@ -61,25 +61,17 @@ function to_vec(X::Diagonal)
 end
 
 function to_vec(X::Transpose)
-
-    x_vec, x_from_vec = to_vec(X.parent)
-
     function Transpose_from_vec(x_vec)
-        return Transpose(x_from_vec(x_vec))
+        return Transpose(permutedims(reshape(x_vec, size(X))))
     end
-
-    return x_vec, Transpose_from_vec
+    return vec(Matrix(X)), Transpose_from_vec
 end
 
 function to_vec(X::Adjoint)
-
-    x_vec, x_from_vec = to_vec(X.parent)
-
     function Adjoint_from_vec(x_vec)
-        return Adjoint(x_from_vec(x_vec))
+        return Adjoint(conj!(permutedims(reshape(x_vec, size(X)))))
     end
-
-    return x_vec, Adjoint_from_vec
+    return vec(Matrix(X)), Adjoint_from_vec
 end
 
 # Non-array data structures

test/to_vec.jl

@@ -25,7 +25,6 @@ function test_to_vec(x::T) where {T}
     x_vec, back = to_vec(x)
     @test x_vec isa Vector
     @test x == back(x_vec)
-    @test back(x_vec) isa T
     return nothing
 end
 
@@ -56,6 +55,9 @@ end
             test_to_vec(Op(randn(T, 4, 4)))
             test_to_vec(Op(randn(T, 6)))
             test_to_vec(Op(randn(T, 2, 5)))
+
+            A = randn(T, 3, 3)
+            @test reshape(first(to_vec(Op(A))), 3, 3) == Op(A)
         end
 
         @testset "Tuples" begin