Eigen NumTraits specialisation doesn't define max_digits10() #744
Description
The NumTraits specialisation which Boost multiprecision provides as part of its Eigen integration is missing a few member functions. One of these is max_digits10 which is required by Eigen 5 for printing matrices containing multiprecision scalars.
Corresponding Eigen issue:
https://gitlab.com/libeigen/eigen/-/issues/2985
where it seems the solution is to either inherit from the base class (to bring in a default) or explicit implement the relevant methods.