How to send a "struct" vector per message?

Question

I am trying to send a vector of "struct" per message, but when defining the message field the following error is generated:

Entering directory '/home/veins/workspace.omnetpp/veins/src' veins/modules/application/clustertraci/ClusterTraCI11p.cc veins/modules/application/clustertraci/ClusterTraCI11p.cc:160:40: error: no viable conversion from 'vector' to 'const vector' frameOfUpdate->setUpdateTable(updateTable);

I read chapter 6 of the OMnet ++ manual, but I don't understand how to solve this problem.

Implementation with error

Message Code (MyMessage.msg):

cplusplus {{
#include "veins/base/utils/Coord.h"
#include "veins/modules/messages/BaseFrame1609_4_m.h"
#include "veins/base/utils/SimpleAddress.h"
#include <iostream>
#include <vector>

struct updateTableStruct {
        int car;
        char update;
};

typedef std::vector<updateTableStruct> UpdateTable;
}}


namespace veins;

class BaseFrame1609_4;
class noncobject Coord;
class noncobject UpdateTable;
class LAddress::L2Type extends void;

packet ClusterMessageUpdate extends BaseFrame1609_4 {
    LAddress::L2Type senderAddress = -1;
    int serial = 0;

    UpdateTable updateTable;

MyApp.cc:

void ClusterTraCI11p::handleSelfMsg(cMessage* msg) {
     if (ClusterMessage* frame = dynamic_cast<ClusterMessage*>(msg)) {

         ClusterMessageUpdate* frameOfUpdate = new ClusterMessageUpdate;
         populateWSM(frameOfUpdate, CH2);
         frameOfUpdate->setSenderAddress(myId);
         frameOfUpdate->setUpdateTable(updateTable);
         sendDelayedDown(frameOfUpdate, uniform(0.1, 0.02));

    }
    else {
        DemoBaseApplLayer::handleSelfMsg(msg);
    }
}

Part of code for analysis in MyApp.h:

  struct updateTableStruct {
        int car;
        char update;
    };

    typedef std::vector<updateTableStruct> UpdateTable;
    UpdateTable updateTable;

Answer 1

You experience a type mismatch: In MyApp.h you define the type UpdateTable, and you do so in MyMessage.h. While these both types have the same content and appear to have the same name, I assume this is not actually the case: one type is UpdateTable (defined at global scope in the file generated based on your message) and the other is MyApp::UpdateTable (defined in your application, assuming you are omitting the class definition in the code you show).

Therefore, the types are different, and they cannot be converted into each other implicitly. In this case this might appear a bit counter-intuitive, as they have exactly the same definition, but they do not have the same name. In the following example the reasoning is shown: Two different types that share the same definition should not necessarily be implicitly convertible into each other:

struct Coordinate {
    int x;
    int y;
};

struct Money {
    int dollars;
    int cents;
};

void test() {
    Coordinate c;
    Money m = c;
}

Gives the following error message:

test.cc:13:8: error: no viable conversion from 'Coordinate' to 'Money'
        Money m = c;
              ^   ~
test.cc:6:8: note: candidate constructor (the implicit copy constructor) not viable: no known conversion from 'Coordinate' to 'const Money &' for 1st argument
struct Money {
       ^
test.cc:6:8: note: candidate constructor (the implicit move constructor) not viable: no known conversion from 'Coordinate' to 'Money &&' for 1st argument
struct Money {
       ^
1 error generated.

Edit: The solution to your specific problem is to remove one of the definitions and include the remaining definition when using it, so you can either remove the UpdateTable definition from the message and include the App header instead, or remove the UpdateTable definition from the App and include the message instead.