template<typename TO, typename FROM, typename = void>
class maxon::corenodes::ConversionNode< TO, FROM, typename >
A ConversionNode is a BatchMicroNode which converts from FROM to TO. To implement and register a core node conversion, you have to use MAXON_CORENODE_REGISTER_CONVERSION with the appropriate types. In addition you have to specialize ConversionNode for those types if the conversion can't be done by a constructor of TO which takes a FROM argument (which is what this ConversionNode template does).