Hessian should be symmetric

[dpsanders]

The Hessian of a function f is a symmetric matrix if f is smooth enough.
Is there a way of having this information made available? I guess not just by returning a SymmetricMatrix, due to type stability.

[FJRubio67]

I have the same problem. I have obtained non-symmetric hessian matrices when using ForwardDiff.hessian. This problem seems to appear when the dimension is higher than 3.

A hackish workaround I am currently using is replacing the lower diagonal by the upper diagonal, but this is a suboptimal strategy.