Using boost::numeric_cast<>

Question

When I want to convert between different integer types, it seems the best syntax is to use boost::numeric_cast<>():

int y = 99999;
short x         


        

Answer 1

You could probably do something like this:

#include 

template
Target saturation_cast(Source src) {
   try {
      return boost::numeric_cast(src);
   }
   catch (const boost::negative_overflow &e) {
      return std::numeric_limits::lowest();
      /* Or, before C++11:
      if (std::numeric_limits::is_integer)
         return std::numeric_limits::min();
      else
         return -std::numeric_limits::max();
      */
   }
   catch (const boost::positive_overflow &e) {
      return std::numeric_limits::max();
   }
}

(For types that support it the error cases could also return -inf/+inf).

This way you let Boost's numeric_cast determine if the value is out of bounds and can then react accordingly.