eventFile/eventFile.C:213:19: warning: 'empty' is deprecated: Since 2020-07; use "bool operator" [-Wdeprecated-declarations]
if(ddtScheme_.empty())
^
/Volumes/OpenFOAM-v2112/src/OpenFOAM/lnInclude/tmp.H:301:9: note: 'empty' has been explicitly marked deprecated here
Fixes this deprecation warning: