Detailed Description

Context object for lookup of magnetic field values.

The magnetic field context is an opaque type which contains experiment specific event context information. This can be used to supply event dependent data to the magnetic field instance, in case it is needed to provide correct field values. The library itself does not make any assumptions on the content of this context type (it is implemented using std::any), but passes a reference through the call-chain to the field implementation. An experiment specific field implementation is then expected to performa cast to the concrete type, and use the contents.

An example use case of the context could be to look up conditions data / records for the value of the magnetic field at the time of the event.