考虑以下代码，

class Interface
{
public:
    Interface(){}
    virtual ~Interface(){}
    virtual void method1() = 0; 
                                  
    virtual void method2() = 0;
};

class Concrete : public Interface
{
private:
    int myMember;

public:
    Concrete(){}
    ~Concrete(){}
    void method1();
    void method2();
};

void Concrete::method1()
{
    // Your implementation
}

void Concrete::method2()
{
    // Your implementation
}

int main(void)
{
    Interface *f = new Concrete();

    f->method1();
    f->method2();

    delete f;

    return 0;
}

在笔者使用的Interface *f = new Concrete();实例在主函数一个抽象类，后来他用delete f;，但这个问题new和delete是，我不喜欢他们。有没有其他方法来实例化这个类？

回答

Concrete c;

c.method1(); // no polymorphism, using concrete directly
c.method2();

Interface* f = &c;

f->method1(); // polymorphism through Interface pointer
f->method2();

Interface& f2 = c;

f2.method1(); // polymorphism through reference
f2.method2();

#include <memory>

std::unique_ptr<Interface> upf = std::make_unique<Concrete>();

upf->method1();
upf->method2();