Boost multiprecision rounding mode

Question

Is there a way to change the rounding mode used in Boost.Multiprecision?

I want to use this library but need to know if I can specify the rounding mode for arithmetic operations on the fly, such that I can guarantee certain properties of operations (eg that they are overapproximating).

Is there a cheap way of knowing whether rounding has happened?

Answer 1

After more research I found out that Boost::Interval with a custom type can preserve the inclusion property. However this requires implementing all the arithmetic with downwards and upwarts rounded results. With this in mind I can equip the Boost::Interval with any floating point implementation I like, eg mpfr_t. For further details see:

http://www.boost.org/doc/libs/1_35_0/libs/numeric/interval/doc/guide.htm