父类析构函数删除具有外部启动元素的子类？

Question

Spaceship.h

#include <iostream>
#include <string>
#include <math.h>
#include <vector>


class Position {

public:
    Position (std::string Name, double x, double y, double z);

private:
    std::string Name;
    double x, y, z; //Coordinates on a 3D map


};

class Flight {

public:
    Flight (Position *Start, Position *End);
    ~Flight();

private:
    Position *Start;
    Position *End;

};


class Spaceship {

public:
    Spaceship (std::string Name, Flight *flightPlan);
    ~Spaceship();

private:
    std::string Name;
    Flight *flightPlan;

};

class Universe {

public:
    Universe ();
    ~Universe ();

    void addSpaceship (Spaceship *Spaceship);

    private:
        std::vector <Spaceship*> *Spaceships; // A vector of Spaceship pointers
        std::vector <Spaceship*>::iterator start, end;
        int numberOfSpaceships;

};

Spaceship.cpp

#include "Spaceship.h"

Position::Position (std::string Name, double x, double y, double z) {
    this->Name = Name;
    this->x = x;
    this->y = y;
    this->z = z;
}


 //------------------------------------------------------------

Flight::Flight (Position *Start, Position *End) {
    this->Start = Start;
    this->End = End;
}


Flight::~Flight () {
    delete this->Start;
    delete this->End;
}



//--------------------------------------------------------------

Spaceship::Spaceship (std::string Name, Flight *flightPlan) {
    this->Name = Name;
    this->flightPlan = flightPlan;
}

Spaceship::~Spaceship () {
    delete this->flightPlan;
}

void Spaceship::printFlightPlan () {
    std::cout << "Spaceship name: " << this->Name << std::endl;
    this->flightPlan->printFlightPlan();
}

//---------------------------------------------------------------

Universe::Universe () {
    this->Spaceships = new std::vector <Spaceship*>();
    this->start = this->Spaceships->begin();
    this->end = this->Spaceships->end();

    this->numberOfSpaceships = Spaceships->size();
}

Universe::~Universe() {
    delete this->Spaceships;

}

void Universe::addSpaceship(Spaceship *Spaceship) {
    this->Spaceships->push_back(Spaceship);
    this->start = this->Spaceships->begin();
    this->end = this->Spaceships->end();
}


int main (void) {   

    Position *Start = new Position("Home", 45.566, 34.5677, -12.4565);
    Position *End = new Position ("Far Far Away", 67.4564, -56.6765, 23.4565);

    Flight *virginFlight = new Flight(Start, End);

    Spaceship *sp1 = new Spaceship("Virgin Mary", virginFlight);
    Spaceship *sp2 = new Spaceship("Something else", virginFlight);


    Universe *alpha = new Universe();

    alpha->addSpaceship(sp1);
    alpha->addSpaceship(sp2);


    delete alpha;

    return 0;
}

好吧，这应该是我最干净的代码版本。它只有构造函数和析构函数。如果我错过了一些变量/函数，请假设它们在那里。这编译并运行得很好。我唯一的问题是内存泄漏。

Valgrind报告分配＆gt;至少删除2倍。

Answer 1

你的程序泄露了。这是由于您的代码中的Spaceship *的std :: vector。只有当STL向量容器包含不是指向对象的指针的对象时，它才能管理和释放它的内部存储器。

这里当您向载体添加Spaceship并且删除alpha时，不会释放主程序中sp1和sp2指向的内存。

在现代C ++中，您应该避免使用原始指针，而是尝试使用智能指针。在这里，我尝试更改您的代码，我认为现在不会泄漏。

SpaceShip.h

#include <iostream>
#include <string>
#include <math.h>
#include <vector>
#include <memory>

class Position {

public:
	Position(std::string Name, double x, double y, double z);

private:
	std::string Name;
	double x, y, z; //Coordinates on a 3D map


};

class Flight {

public:
	Flight(Position *Start, Position *End);
	~Flight();
	void printFlightPlan();
private:
	Position *Start;
	Position *End;

};


class Spaceship {

public:
	Spaceship(std::string Name, Flight *flightPlan);
	~Spaceship();
	void printFlightPlan();

private:
	std::string Name;
	Flight *flightPlan;

};

class Universe {

public:
	Universe();
	~Universe();

	void addSpaceship(std::shared_ptr<Spaceship>);

private:
	std::vector <std::shared_ptr<Spaceship>> *Spaceships; // A vector of Spaceship pointers
	std::vector <std::shared_ptr<Spaceship>>::iterator start, end;
	int numberOfSpaceships;

};

#include "Spaceship.h"

Position::Position(std::string Name, double x, double y, double z) {
	this->Name = Name;
	this->x = x;
	this->y = y;
	this->z = z;
}


//------------------------------------------------------------

Flight::Flight(Position *Start, Position *End) {
	this->Start = Start;
	this->End = End;
}


Flight::~Flight() {
	/*delete this->Start;
	delete this->End;*/
}

void Flight::printFlightPlan() {
	
}


//--------------------------------------------------------------

Spaceship::Spaceship(std::string Name, Flight *flightPlan) {
	this->Name = Name;
	this->flightPlan = flightPlan;
}

Spaceship::~Spaceship() {
	delete this->flightPlan;
}

void Spaceship::printFlightPlan() {
	std::cout << "Spaceship name: " << this->Name << std::endl;
	this->flightPlan->printFlightPlan();
}

//---------------------------------------------------------------

Universe::Universe() {
	this->Spaceships = new std::vector<std::shared_ptr<Spaceship>>;
	this->start = this->Spaceships->begin();
	this->end = this->Spaceships->end();

	this->numberOfSpaceships = Spaceships->size();
}

Universe::~Universe() {
	//delete this->Spaceships;

}

void Universe::addSpaceship(std::shared_ptr<Spaceship> Spaceship) {
	this->Spaceships->push_back(Spaceship);
	this->start = this->Spaceships->begin();
	this->end = this->Spaceships->end();
}


int main(void) {

	Position *Start = new Position("Home", 45.566, 34.5677, -12.4565);
	Position *End = new Position("Far Far Away", 67.4564, -56.6765, 23.4565);

	Flight *virginFlight = new Flight(Start, End);

	std::shared_ptr<Spaceship> sp1(new Spaceship("Virgin Mary", virginFlight));
	std::shared_ptr<Spaceship> sp2(new Spaceship("Something else", virginFlight));


	Universe *alpha = new Universe();

	alpha->addSpaceship(sp1);
	alpha->addSpaceship(sp2);


	delete alpha;

	return 0;
}