Vector, class, and iterator issues

[Escapetomsfate]

Hello, I'm new to this forum.

I'm making a Combat addon fro the space flight simulator, orbiter (www.orbitersim.com). You include compiled libraries to make the addons. I'm pretty sure my problem is not orbiter specific, though. Here is the code that is causing my error:

DLLCLBK void opcPreStep(double simt, double simdt, double mjd)
{
	//loop through all weapons, and destroy them.
	for (vector<Weapon>::iterator it = WeaponList.begin(); it != WeaponList.end();++it)
  {
	 it->explode();
	}
};

opcPreStep is called by the core every timestep. WeaponList is a vector of the Weapon class.
I compile my addon, and I get a crash to desktop. If I change it to *it, I get an illegal indirection error. can anyone help? thanks.

[Plasmator]

1. Thanks for using code tags.
2. The problem isn't in the snippet that you've posted.
3. Lose the last semicolon.
4. After you've fixed the underlying issue, if all you're doing is calling destroy in opcPreStep, then you can replace your for-loop with the cleaner std::for_each variant:
   

   std::for_each(WeaponList.begin(), WeaponList.end(), std::mem_fun_ref(&Weapon::explode));

[Escapetomsfate]

1. Thanks for using code tags.
2. The problem isn't in the snippet that you've posted.
3. Lose the last semicolon.
4. After you've fixed the underlying issue, if all you're doing is calling destroy in opcPreStep, then you can replace your for-loop with the cleaner std::for_each variant:
   

   std::for_each(WeaponList.begin(), WeaponList.end(), std::mem_fun_ref(&Weapon::explode));

Thank you for the quick reply.

Where do you think the problem lies, then? Persumably the WeaponList vector? Or perhaps the Weapon class?
Here is the declaration of the weapon class;

//The Weapon class.
class Weapon {
	//for safety, all variables are accessed privately.
private:
int FireVesselIndex;
const char *explodemesh;													//A mesh to  be spawned on explosion.
const char *name;															//The name of the weapon.
const char *classname;														//Classname (CFG File) of the vessel to be 'fired'

bool missile;																//Whether it's a missile (full throttle on fire) or not.
bool exploded;																//Whether the vessel has exploded or not.
bool fired;																	//Whether the vessel has been fired or not.

public:

Weapon(const char *newname,const char *newclassname, bool newmissile);		//Constructor.
~Weapon() {}																//Destructor.

bool fire();																//The fire function.
bool explode();																//The explode function - replaces the current mesh with the explosion mesh.

//Update status function.
void UpdateStatus() {
	this->vessel->GetStatusEx(&stat);
}
OBJHANDLE objvessel;					//The OBJHANDLE for the weapon.
VESSEL *vessel;							//The VESSEL handle for the weapon.
VESSELSTATUS2 stat;						//The current status of the weapon. Given properties on fire.
//Set functions- for changing private data.
void SetExplodeMesh(const char*newexplodemesh){
	explodemesh=newexplodemesh;
}
};

You may not recognise some data types, such as OBJHANDLE etc - they are ORbiter specific.

Thanks for helping.

[ZuK]

The Weapon class with all that pointer members should propably have a copy constructor and an assignement operator.
But then it seems to be incomplete and I can't tell for shure.
Kurt

[Plasmator]

As ZuK pointed out, there's not enough information to determine the root cause of your problem(s).
Having said that, start taking advantage of standard facilities such as std::string -- they'll make your life a lot easier.

P.S.: Debuggers are very useful tools.

[Escapetomsfate]

As ZuK pointed out, there's not enough information to determine the root cause of your problem(s).
Having said that, start taking advantage of standard facilities such as std::string -- they'll make your life a lot easier.

P.S.: Debuggers are very useful tools.

I have to use const char, because that's what the APIs require. I can't use a debugger either, because Orbiter has no built in debugging information.

EDIT: more info on my problem;

I can run an empty iterating loop through the vector fine, I only get a CTD after using a member function of the iterator's class (Weapon). I've checked that there is nothig wrong with explode().

The initialisation of the vector:

//This vector contains all Weapons in the scenario. Weapons are added on construction.
vector <Weapon> WeaponList;

ANOTHER EDIT:
Ok, I've managed to get vc's debugger working with orbiter - got this -
First-chance exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
Unhandled exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
First-chance exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
Unhandled exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
First-chance exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
Unhandled exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
First-chance exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
Unhandled exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
First-chance exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
Unhandled exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
First-chance exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
Unhandled exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
First-chance exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.
Unhandled exception at 0x00414d6c in orbiter.exe: 0xC0000005: Access violation reading location 0xc304d107.

[laserlight]

I have to use const char, because that's what the APIs require.

You can get a const char* from a std::string by way of the c_str() member function.

[laserlight]

Can I ask why it is necessary to use std::string and then convert, when you can just pass a const char?

So you are relieved of the burden of memory management. Also, when you do need to manipulate strings other than with the API that you are using, it tends to be safer and easier due to the functions provided.

[Escapetomsfate]

I only get an error when I use a function of the iterator (it, using Weapon class functions).

How do I make a class push back itself on construction? I'm sure that's the problem.

[Paul McKenzie]

I only get an error when I use a function of the iterator (it, using Weapon class functions).

Then that loop would never execute if the WeaponList is empty. Look at the for loop constraints. Second, if that loop did execute, that means that the WeaponList is not empty, and one of the item's in that list has an explode() function that is buggy, or the item itself is buggy.

How do I make a class push back itself on construction?

I don't understand your question. How would that fix the issue I stated above?

I'm sure that's the problem.

Hopefully you are not guessing at what the problem is. You never should guess, you have to actually debug, find the cause of the problem, and then offer a diagnosis to fix the problem.

Regards,

Paul McKenzie