extern or define in header?

Hello guys for another game I am working on I am trying to make a list of types of weapons that you can use and I was wondering how would you would go about this basically I am making pre-defined structs of weapons and armor. Here is the question should I just define them in a header file or should or extern them in the header and define them in the cpp file or is it a matter of taste?
heres some code if you are confused cause well I do that sometimes.

Code:

#ifndef weapon_h
#define weapon_h

#include <string>

struct weapon
{
    std::string name;    //Weapon's name;
    int power;           //How much it add's to your attack
    int retailPrice;     //How much that it cost in a shop
    int sellingPrice;    //How much you can sell it for
    bool isUpgradeable;  //If is is allowed to be upgraded
};

#endif//weapon_h

Now should I do this

Code:

#ifndef weaponAttributes_h
#define weaponAttributes_h

#include "weapon.h"
//name,power,retailPrice,selling price,is it upgradable

weapon sword = {"sword",10,50,30,false};

#endif//weaponsAttributes_h

or define the sword into the cpp file and extern it in the header

Can be done in many ways. I'd make some kind of factory class:

Code:

struct Weapon
{
  Weapon(const std::string& NewName, int NewPower)
  {
    Name = NewName;
    Power = NewPower;
  }

  std::string Name;
  int Power;
};

class Weapons
{
  public:
    void CreateWeapon(const std::string& Name, int Power)
    {
      WeaponList.insert(std::make_pair(Name, Weapon(Name, Power)));
    }

    Weapon* GetWeapon(const std::string& Name)
    {
       return &WeaponList[Name];
    }

  protected:
    std::map<std::string, Weapon> WeaponList;
};

Weapons weapons;

and to create a new weapon:

Code:

weapons.CreateWeapon("Dagger", 12);
weapons.CreateWeapon("Sword", 46);

and to use the weapon:

Code:

Weapon* weapon = weapons.GetWeapon(Player.CurrentWeapon());
enemy.InflictDamage(weapon->Power);

or something...