[protobuf] Deleting a message from a repeated message (ver. 2.6 PB)

[Carl]

Well I am about to expose my ignorance on so many levels.

I have a message, that contains repeated messages, something like this:

message person {
optional string personName =1;
optional float age =2;
optional int32 ssn =3;
} 


message simpleDB {
optional string dbName =1;
repeated person people =2;
} 


Now I have read that PB's don't have a "delete[arrayIndex]" for performance 
reasons. Instead the idea is too swap messages, so the message to delete is 
at the end of the list, and do a removeLast();

So I can swap messages via something like:

      sally->Swap(dick);

Where sally and dick are mutable pointers of type person. ( 
 sally=myDB->mutable_people(i);     )

But now how I do I do the final act of removing the last message from the 
list of "people" messages?

I have attached "easy to follow" code to help explain what I am doing. 
(seems I am not the only one who struggles with this)

Thanks.

Regards
Carl


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#include <iostream>


#include "simple_pb.h"

int main()
{
	int i;
    std::cout << "Start\n";

    simpleDB *myDB;
    person *personPB;

    myDB= new simpleDB;
    myDB->set_dbname("Overlord");

    std::cout << "DB name=" << myDB->dbname() << "\n";

    personPB=myDB->add_people();
    personPB->set_personname("Tom");
    personPB->set_age(1.);
    personPB->set_ssn(10);

    personPB=myDB->add_people();
    personPB->set_personname("Dick");
    personPB->set_age(2.);
    personPB->set_ssn(9);

    personPB=myDB->add_people();
    personPB->set_personname("Harry");
    personPB->set_age(3.);
    personPB->set_ssn(8);

    personPB=myDB->add_people();
    personPB->set_personname("Sally");
    personPB->set_age(4.);
    personPB->set_ssn(7);


    std::cout << "Current order:\n";
    for(i=0;i<myDB->people_size();i++)
    	std::cout <<  "\t" << myDB->people(i).personname()
		<<  "\t" << myDB->people(i).age()
		<<  "\t" << myDB->people(i).ssn()
		<< "\n";


    // swap Sally and Dick
    person *dick;
    person *sally;

    for(i=0;i<4;i++)
    {
    	if(myDB->people(i).personname() == "Dick")
    	{
    		std::cout << "Found Dick..." << i << "\n";
    		dick=myDB->mutable_people(i);
    	}
    	if(myDB->people(i).personname() == "Sally")
    	{
    		std::cout << "Found Sally..." << i << "\n";
    		sally=myDB->mutable_people(i);
    	}

    }

    std::cout << "Swapping Sally and Dick:\n";
    sally->Swap(dick);

    std::cout << "Current order:\n";
        for(i=0;i<myDB->people_size();i++)
        	std::cout <<  "\t" << myDB->people(i).personname()
    		<<  "\t" << myDB->people(i).age()
    		<<  "\t" << myDB->people(i).ssn()
    		<< "\n";

     std::cout << "Removing Dick:\n";
     // What goes here?

     std::cout << "Final order:\n";
             for(i=0;i<myDB->people_size();i++)
             	std::cout <<  "\t" << myDB->people(i).personname()
         		<<  "\t" << myDB->people(i).age()
         		<<  "\t" << myDB->people(i).ssn()
         		<< "\n";

    std::cout << "End\n";
    return 0;
}