The following code obtains the layer symbol table from the database, creates a new layer table record, and names it (ASDK_MYLAYER). The layer table record is then added to the layer table.
void createNewLayer() { AcDbLayerTable *pLayerTable; acdbHostApplicationServices()->workingDatabase() ->getSymbolTable(pLayerTable, AcDb::kForWrite); AcDbLayerTableRecord *pLayerTableRecord = new AcDbLayerTableRecord; pLayerTableRecord->setName("ASDK_MYLAYER"); // Defaults are used for other properties of // the layer if they are not otherwise specified. // pLayerTable->add(pLayerTableRecord); pLayerTable->close(); pLayerTableRecord->close(); }