allow any dims object in reorder

src/utils.jl

@@ -12,6 +12,8 @@ If no axis reversal is required the same objects will be returned, without alloc
 """
 function reorder end
 
+reorder(x, A) = reorder(x, dims(A))
+reorder(x, ::Nothing) = throw(ArgumentError("object has no dimensions"))
 reorder(x, p::Pair, ps::Vararg{Pair}) = reorder(x, (p, ps...))
 reorder(x, ps::Tuple{Vararg{Pair}}) = reorder(x, Dimensions.pairdims(ps...))
 # Reorder specific dims.

test/utils.jl

@@ -78,10 +78,11 @@ end
 
     # reorder with dimension lookups
     rev = reverse(da, dims=Y)
-    reo = reorder(rev, dims(da))
+    reo = reorder(rev, da)
     @test rev != da
     @test reo == da
     @test dims(reo) == dims(da)
+    @test_throws ArgumentError reorder(rev, :test)
 end
 
 @testset "modify" begin