[Boost-users] Boost Units initialize quantity with signaling NaN

Hi, I’m trying to find a way to initialize a Boost Unit with a signaling NaN, not just a NaN with the signal cleared. It seems that the only way to initialize a quantity is by multiplying by the unit, and that multiplication clears the signal on the NaN. I know I can just modify the quantity.hpp header and initialize the default constructor val_ member with the signaling NaN, but I was hoping for a cleaner solution. Here’s an example (typed in by hand, not tested): const double s_nan = std::numeric_limits<double>::signaling_NaN(); typedef quantity acceleration_t; BOOST_UNITS_STATIC_CONSTANT(acceleration_u, acceleration); acceleration_t a(s_nan * acceleration_u); // <— this clears the signal on the NaN Has anyone encountered this or know of a more elegant solution than modifying the quantity.hpp header? — Noel