boost::random::traits::make_unsigned_or_unbounded — Converts the argument type T to either an unsigned type or an unbounded integer type.
This trait has a single member
type which is either the unsigned type corresponding to T or an unbounded integer type. This trait is used to generate types suitable for the calculation of a range: as a result if T is signed, then member
type should define a type with one more bit precision than T. For built-in types this trait defaults to
boost::make_unsigned<T>::type. For user defined types it simply asserts that the argument type T is either an unbounded integer, or an unsigned one (using std::numeric_limits). User defined specializations may be provided for other cases.