Usage example:

Message message; // quickfix message

// Create a strongly type wrapper for quickfix message:
SecurityDefinitionMessage wrapper =  new SecurityDefinitionMessage(message);

// Access to message fields:
string srId = wrapper.SecurityReqID;

// Nullable<> for not required fields:
double? rate = wrapper.Instrument.CouponRate;

// Array for group of fields:
for (uint i = 0; i < wrapper.Instrument.NoEvents.Count; i++)
{
      InstrumentComponent.NoEventsGroup.NoEventsGroupItem item = m.Instrument.NoEvents[i];
      // ...
}