I have a class, and i try to create an object of it but it give me error in compilation.
The error is something like "]b]undefined reference to 'Game::PowerUp::powerups[/b]", in constructor of Game::PowerUp.
The error also contain another 2 error : also are undefined reference but under ~PowerUp destructor.
it compiled well actually if i dont create an object of it in test.cpp(main program to create objects), but once i coded this "
PowerUp* power = new PowerUp(t, s, 4, 4);" in test.cpp, the compilation fails and give that that error message.
here is my code:
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/*** Power Up class ***/
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class PowerUp : public Health {
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public:
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PowerUp(
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const Terrain* t,
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Screen* s,
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unsigned startX,
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unsigned startY,
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unsigned p = STD_POWER_UP
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) : Health(t, s, startX, startY, p) {
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powerups.insert(this);
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}
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virtual ~PowerUp() { powerups.erase(this); }
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virtual void Use(Character* c) {
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Health::Use(c);
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delete this; // Powerups disappear once used
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}
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static PowerUp* Find(unsigned atX, unsigned atY) {
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set<PowerUp*>::const_iterator it;
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for (it = powerups.begin(); it != powerups.end(); it++) {
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if ((*it)->xPos == atX && (*it)->yPos == atY) {
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return (*it);
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}
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}
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return 0;
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}
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virtual char GetSymbol() const { return '@'; }
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private:
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unsigned power;
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static set<PowerUp*> powerups;
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