[boost] [numeric][ublas] no serialize methods for triangular_matrix and symmetric_matrix?

Hi, I noticed that both vector and matrix in boost::numeric::ublas have a serialize methods, but triangular_matrix and symmetric_matrix do not. Is there a reason for that, or is it an oversight? I think it would be great if more boost classes came with serialize methods out of the box. Best regards, Hans -- Hans Dembinski https://github.com/HDembinski Proposed for Boost: histogram https://github.com/HDembinski/histogram Automatic one-dimensional unfolding of data distributions https://github.com/HDembinski/aru-unfolding