Identifying temporary object creation in Eigen

As the documentation in Eigen C++ library points out at many places, to get the maximum performance in terms of the computation time, we need to avoid temporary objects as far as possible. In my application, I deals with Dynamic size matrices. I would like to know the creation of temporary matrices in my calculations. Is there any general method to identify the creation of the temporary matrices?

For example,

Eigen::MatrixXf B, C, D;
....some initialization for B, C, D
Eigen::MatrixXf A = B*C+D;

How to check how many temporary matrices are created while realising this operation?