Anonymous Declarationenum : unsigned int { ... }; TopicsConstantsBIDIRECTIONAL_ECHO_CANCELING_SPEAKERPHONEBIDIRECTIONAL_ECHO_SUPPRESSING_SPEAKERPHONEBIDIRECTIONAL_HANDSETBIDIRECTIONAL_HEADSETBIDIRECTIONAL_SPEAKERPHONE_NO_ECHO_REDXBIDIRECTIONAL_UNDEFINED