c++ - 如何在 switch 语句中声明一个全局对象

Question

我遇到了一个问题，我需要根据用户输入为类声明一个对象。问题是对象的范围卡在switch语句中，我想知道有没有办法让它公开。

//ask the user to choose the class of the first fighter
    cout << "Welcome to the fighting arena! Would you like the first competitor to be a FIGHTER <1>, a WIZARD <2>, a ROGUE <3>, or a RANGER <4>?" << endl;
    cin >> competitor1;
    cout << "And what is the name of the competitor?" << endl;
    cin >> name1;

    //creates an object in the appropriate class and initializes it
    switch (competitor1)
    {

    case 1:
    {
        Fighter Battler1(name1);
        break;
    }

    case 2:
    {
        Wizard Battler1(name1);
        break;
    }

    case 3:
    {
        Rogue Battler1(name1);
        break;
    }
    case 4:
    {
        Ranger Battler1(name1);
        break;
    }
    default:
        cout << "Sorry please enter a valid number!" <<endl << endl;
        break;
    }

cout << Battler1.hp //this is undefined because of the scope

是的，所有内容都写在主要功能中，我知道问题是作用域，只需要一种方法来解决它。

Answer 1

我根本不会在这里使用 switch case，而是使用一组仿函数，每个仿函数创建不同类型的战斗机并返回指向其基础的指针，即

template<typename T>
std::unique_ptr<Champion> Create( ) { return std::make_unique<T>( ); }

std::function<std::unique_ptr<Champion>(void)> createFunctions [] = {
    Create<Fighter>
   ,Create<Rogue>
   ,Create<Wizard>
   ,Create<Ranger>
};

用法:

std::cin >> competitor1;
std::unique_ptr<Champion> Battler1 = createFunctions[competitor1];
std::cout << Battler1->hp;