[eigen] Tensor reduction with .all() or .any()

[Alberto Luaces]

Hello, I'm having problems trying to find if some condition is failing for any 
of the elements of a tensor:

Eigen::Tensor<double, 5> errors(21, 21, 21, 21, 21);

...

// This does not work
bool allTestsPassed = (errors < tolerance).all();

I have tried 

Eigen::Tensor<bool, 0> allTestsPassed;

 and 

Eigen::Tensor<bool, 1> allTestsPassed(1);

but I cannot get the result, either because there are compilation errors or 
either I have runtime size mismatches when assigning the value of 
allTestsPassed variable.

Thanks.

-- 
  Alberto