Can anyone please simply this statement.

[Former Member]

eo_field_catalog ?= cl_abap_tabledescr=>describe_by_data( p_data = it_flight ).

We write this statement in feeder class for list or search GUIBB.

Why wide casting is compulsory and don't we have to do narrow casting before doing wide casting?

Thanks in advance,

Amey

[Former Member]

This is how I simplified it and its working

DATA: lo_ref type REF TO CL_ABAP_TYPEDESCR.
lo_ref = cl_abap_tabledescr=>describe_by_data( p_data = it_flight ).
eo_field_catalog ?= lo_ref.