Parameter list, pseudo-database, approach not scalable!

[Archaea]

I have a file called jobDatabase.h which I would like to be able to fill up with as many _jobs as I feel like (maybe hundreds), but some of my function calls require me to load-in each job. Is there some way to avoid this need, b/c the argument list would become absurdly long.

I've considered using matrices, but can you mix data-types within an array? I don't think so.

I could maybe have one function to pre-load a desired set from the database of _job into job1, job2, job3, job4, but I'd prefer they all be available in whatever function I need them.

Please help!

class _job
{
public:
	string name, title;
	int salary, creditYearsMin;
};

#ifndef JOBDATABASE_H
#define JOBDATABASE_H

_job job1;
job1.name = "Labor Ready";
job1.title = "LABORER";
job1.salary = 12500;
job1.creditYearsMin = 0;

_job job2;
job2.name = "Widget Factory";
job2.title = "ENGINEER";
job2.salary = 65000;
job2.creditYearsMin = 4;

_job job3;
job3.name = "Hospital";
job3.title = "NURSE";
job3.salary = 150000;
job3.creditYearsMin = 6;

_job job4;
job4.name = "Hospital";
job4.title = "DOCTOR";
job4.salary = 350000;
job4.creditYearsMin = 8;

#endif 

int _tmain(int argc, _TCHAR* argv[])
{
	init();
	
#include "jobDatabase.h"

	_user you;
	initUser(you);

	life(you, job1, job2, job3, job4);
	
	dispUser(you);
	system("PAUSE");
	return 0;
}

void life (_user &you, _job job1, _job job2, _job job3, _job job4)

findJob(you, job1, job2, job3, job4);

etc.

[Bazzy]

Try with a deque of _job objects ( http://www.cplusplus.com/reference/stl/deque/ )

[Archaea]

Okay, I've got them loaded into a deck. Now, how do I pass them as a function parameter?

Line: 17 void life (_user &you, deque dqJobList, _job job1, _job job2, _job job3, _job job4);

Line: 28 life(you, dqJob, job1, job2, job3, job4);

Line: 35 void life (_user &you, deque dqJobList, _job job1, _job job2, _job job3, _job job4)

(17): error C2955: 'std::deque' : use of class template requires template argument list

(28): error C2664: 'life' : cannot convert parameter 2 from 'std::deque<_Ty>' to 'std::deque'
with
[
_Ty=_job
]

(35): error C2955: 'std::deque' : use of class template requires template argument list
c:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\include\deque(970) : see declaration of 'std::deque'

[Bazzy]

You need to give deque the template argument: deque<_job>.
When you pass the deque you don't need to pass again all the objects as they are already contained in it

[Archaea]

When you pass the deque you don't need to pass again all the objects as they are already contained in it

Yeah, I know, sorry, those were in for my own debugging/checking.

You need to give deque the template argument: deque<_job>.

I do:
deque<_job> dqJob(5);

My life function doesn't like when I call dqJob a _job or a deque, so what do I call it?

void life (_user &you, _job dqJob

line 28:
life(you, dqJob

(28): error C2664: 'life' : cannot convert parameter 2 from 'std::deque<_Ty>' to '_job'
with
[
_Ty=_job
]

[Archaea]

Aha!

void life (_user &you, deque<_job> dqJob

lol

[Bazzy]

You should pass containers by reference, because they are expensive to copy:
void life (_user &you, const deque<_job> &dqJob);

[jRaskell]

Looks like you may want to use an actual database as opposed to a pseudo-db, expecially if you're going to have hundreds of job entries. This looks like a classic example for a relational database.

[Archaea]

Thanks, Bazzy. I'll read up on const.

jRaskell, yeah, you're probably right, it may be time to branch out. Any suggestions on where to get started with a relational db?

[Bazzy]

Notice the '&' after the type, const TYPE & means 'a const reference of TYPE', which means that the argument doesn't get copied (reference) and that you can't modify it in the function (const)

[Archaea]

Thanks for the explanation. I did in fact forget the '&'.