如何循环遍历向量fleetX和fleetY并访问"Ship“基类中的函数？

Question

我想创建两个舰队，最多有9艘船，并让他们互相战斗。我的老师告诉我，我必须使用共享的指针和向量。

• 基类：
• 继承类:驱逐舰、巡洋舰、猎人

main.cpp

int main(int argc, const char * argv[]) {

std::vector<std::shared_ptr<Ship>> fleetX;
std::vector<std::shared_ptr<Ship>> fleetY;

Battlefield game;

game.createFleet(fleetX, fleetY);

return 0;

}

createFleet()在我的战场类中

void Battlefield::createFleet(std::vector<std::shared_ptr<Ship>> fleetX, std::vector<std::shared_ptr<Ship>> fleetY) {

int hunter, destroyer, cruiser, player_Input;

// PLAYER 1
do {
    cout << "BATTLEFIELD" << endl;
    cout << "Player_1" << endl;
    cout << "Choose the number of ships you want in your fleet (9 maximum): ";
    cin >> player_Input;
} while (player_Input < 1 || player_Input > 9);
cout << endl;

do  {
    cout << "Choose " << player_Input << " in total ships from the following:" << endl;
    cout << "HUNTER - Special Attack (Critical Hit)" << endl;
    cout << "DESTROYER - Special Attack (Target Search)" << endl;
    cout << "CRUISER - Special Attack (Bombardment)" << endl << endl;
    cout << "HUNTER: ";
    cin >> hunter;
    cout << "DESTROYER: ";
    cin >> destroyer;
    cout << "CRUISER: ";
    cin >> cruiser;
    cout << endl;
} while (hunter + destroyer + cruiser != player_Input);

int iterator = 0;
while (iterator < hunter) { fleetX.push_back(std::shared_ptr<Ship>(new Hunter())); iterator++;} iterator = 0;
while (iterator < destroyer) { fleetX.push_back(std::shared_ptr<Ship>(new Destroyer())); iterator++;} iterator = 0;
while (iterator < cruiser) { fleetX.push_back(std::shared_ptr<Ship>(new Cruiser())); iterator++;} iterator = 0;

}

Answer 1

您正在按值传递向量，从而创建一个新副本，即不修改原始向量。

尝试通过引用传递向量

void Battlefield::createFleet(
  std::vector<std::shared_ptr<Ship>>& fleetX, 
  std::vector<std::shared_ptr<Ship>>& fleetY
) {
  // rest of code
}

编辑：

使用std::make_shared<Hunter>()而不是std::shared_ptr(new Hunter())