#include <boost/qvm/quat_operations.hpp>
namespace boost
{
    namespace qvm
    {
        //Only enabled if: is_quat<A>::value
        template <class A>
        typename deduce_quat<A>::type
        inverse( A const & a );
    }
}
Computes the multiplicative inverse of a, or the conjugate-to-norm ratio.
If the magnitude of a is zero, throws zero_magnitude_error.
If a is known to be unit length, conjugate is equivalent to inverse, yet it is faster to compute.