Specifying precision in vector<mpf_class>?

[Kevin Ryde]

gerardo.ballabio@unimib.it (Ballabio Gerardo - Dip. di Scienza dei Materiali) writes:
>
> Another point is that by design, we wanted mpf_class to be a very
> lightweight wrapper to mpf_t with no extra functionality (for this
> reason we've had a rather strong dispute about whether mpq_class
> should canonicalize its input), and the template approach seems to
> depart from that. (Kevin, Torbjorn, what do you think?)

Another way to specify a precision would be fine, if it made life
easier.  Maybe attacking the current difficulties with subclassing
would be a more general way to cover various such things.

The extras I'd like to avoid is mainly fields or flags in mpX_class
but not in mpX_t.  If there's some feature to be associated with
variables then ideally it should be available in C programs too.