boost::geometry::promote_floating_point
promote_floating_point.hpp
typename T T
typename PromoteIntegerTo PromoteIntegerTo double
boost::mpl::if_< boost::is_integral< T >, PromoteIntegerTo, T >::type typedef boost::mpl::if_< boost::is_integral<T>, PromoteIntegerTo, T >::type boost::geometry::promote_floating_point< T, PromoteIntegerTo >::type type

Meta-function converting, if necessary, to "a floating point" type.

- if input type is integer, type is double

- else type is input type

- boost::geometry::promote_floating_point
  type