CODEWITHSUNDEEP
c++visual-studio-2010inheritancelinker
user981643
user981643

Reputation: 5

MSVC++ 2010 Express linker error LNK2005

I have a few files in my project that aren't working the way I want them to.

Basically, I have a class, called Entity. It's defined in Entity.h and the functions are in Entity.cpp, so that's all swell. I then have a child class, called PlayerShip. It's defined the same way, in two files.

(Entity.h is included in PlayerShip.h)

When I include PlayerShip.h in playership.cpp AND in main.cpp the linker throws a LNK2005 error - the constructor is defined twice. Technically though, wasn't it just prototyped twice?

main.cpp

-- snip --

#include "PlayerShip.h"
using namespace std;

-- snip --

// PLAYER
int playerFlags = DRAW | EVENT | LOGIC;
playerShip pship = playerShip(playerFlags, iManager.getImage("ship.png"), 4);
Entity* player = eManager.addEntity(&pship);

etc, int main() yada yada yada

PlayerShip.h

#include "entity.h"

class playerShip : public Entity
{
private:
    int horizontalSpeed, verticalSpeed;
    int moveSpeed;

public:
    playerShip(int allow, const sf::Image &img, int speed);
    void handleLogic();
    void handleEvents(sf::Event ev, sf::RenderWindow *screen);
};

playership.cpp

#include "PlayerShip.h"

playerShip::playerShip(int allow, const sf::Image &img, int speed) : Entity(allow, img), horizontalSpeed(0), verticalSpeed(0)
{
moveSpeed = speed;
}

void playerShip::handleEvents(sf::Event ev, sf::RenderWindow *screen)
{
while (screen->GetEvent(ev))
{
    if (ev.Type == sf::Event::KeyPressed)
    {
        if (ev.Key.Code == sf::Key::Left)
            horizontalSpeed = -1 * moveSpeed;
        if (ev.Key.Code == sf::Key::Right)
            horizontalSpeed = 1 * moveSpeed;
        if (ev.Key.Code == sf::Key::Up)
            verticalSpeed = -1 * moveSpeed;
        if (ev.Key.Code == sf::Key::Down)
            verticalSpeed = 1 * moveSpeed;
    }
}
}

void playerShip::handleLogic()
{
setX(float(getX()+horizontalSpeed));
setY(float(getY()+verticalSpeed));
}

I have no clue why this is happening. =S

Upvotes: 0

Views: 314

Answers (1)

Cpt. Red
Cpt. Red

Reputation: 102

I believe that you have forgotten include guards or using pragma once. These will make sure that the header will only be read once witch is good.

Include guard example:

#ifndef ENTITY_H
#define ENTITY_H

class Entity
...

#endif // ENTITY_H

Pragma once:

#pragma once

class Entity
...

Note that pragma once isn't standard but is still supported by practically all compilers.

Upvotes: 1

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