c++ - C++ 继承重载具有不同参数的函数

Question

我正在开发一个使用类继承并且在基类和派生类中都需要大量重载的项目，我已经简化了代码，但我不想不必要地复制和粘贴，因为这应该是继承的用途。

#include <iostream>

class Base
{
public:
    Base() = default;

    //base const char* overload
    void foo(const char* message)
    {
        std::cout << message << std::endl;
    }
    //other overloads ...
};
class Derived : public Base
{
public:
    Derived() = default;

    //derived int overload
    void foo(int number)
    {
        std::cout << number << std::endl;
    }
};

int main()
{
    Derived b;
    b.foo(10); //derived overload works
    b.foo("hi"); //causes error, acts as if not being inherited from Base class
    return 0;
}

Answer 1

您可以在派生类中使用 using 声明，例如

using Base::foo;

使基类中声明的重载函数 foo 在派生类中可见。

这是插入 using 声明的程序。

#include <iostream>

class Base
{
public:
    Base() = default;

    //base const char* overload
    void foo(const char* message)
    {
        std::cout << message << std::endl;
    }
    //other overloads ...
};
class Derived : public Base
{
public:
    Derived() = default;

    using Base::foo;
    //derived int overload
    void foo(int number)
    {
        std::cout << number << std::endl;
    }
};

int main()
{
    Derived b;
    b.foo(10); //derived overload works
    b.foo("hi"); //causes error, acts as if not being inherited from Base class
    return 0;
}

程序输出为

10
hi