Specifying precision in vector<mpf_class>?
Ballabio Gerardo - Dip. di Scienza dei Materiali
Tue, 26 Aug 2003 12:01:34 +0200
I've started to look at the details and found that the
mpf_class<prec> thing can't be done straightforwardly.
The problem is that in the current implementation, mpf_class is a
specialization of a generic "gmp_expr" template class, renamed with a
typedef like this:
typedef gmp_expr<mpf_t> mpf_class;
An mpf_class with the precision as a template argument would be
declared like this:
template <int N> typedef gmp_expr<mpf_t, N> mpf_class<N>;
but such a "template typedef" is not a valid C++ construct. In fact
there's no way to implement it, so far as I know.
Thus, mpf_class must be defined independently on gmp_expr, but then
we'd have two distinct types and this would require the duplication
of a lot of stuff. I believe it can still be done, but I doubt that
it's worth the effort.