c++ - C类继承B类和A类，B类也继承A类

Question

我想记录来自基类 B 和派生类 C 的消息，区分哪个类记录了消息:

#include "iostream"

class Logger {
public:
    Logger(std::string name) : name_(name) {}
    void log(std::string msg) { std::cout << name_ << ": " << msg << std::endl; }
private:
    std::string name_;
};

class B : public Logger {
public:
    B() : Logger("Class B" ) {}
    void doSomethingInB() {
        log("B doing something");
    }
};

class C : public B, public Logger {
public:
    C() : Logger("Class C" ) {}
    void doSomethingInC() {
        log("C doing something");
    }
};

int main() {
    B* b = new B();
    C* c = new C();

    b->doSomethingInB(); // I want this to output: Class B: B doing something

    c->doSomethingInC();
    c->doSomethingInB(); // I also want this to output: Class B: B doing something

    return 0;
}

我收到错误“由于歧义 [默认启用]，在‘C’中无法访问直接基础‘Logger’”，这是不言自明的。

我可以实现什么不同的模型来做到这一点？

Answer 1

编辑:为了响应您对 c->doSomethingInB(); 需要打印 Class B: B doing something 的要求，请考虑继承之上的组合，因为你需要 B 作为它自己的子类，它的记录器真的和 C 的不一样(除非这里有更多的要求)。示例:

class Logger {
public:
    Logger(std::string name) : name_(name) {}
    void log(std::string msg) { std::cout << name_ << ": " << msg << std::endl; }
private:
    std::string name_;
};

class B {
public:
    B() : logger_("Class B" ) {}
    void doSomethingInB() {
        logger_.log("B doing something");
    }
private:
  Logger logger_;
};

class C : public B {
public:
    C() : logger_("Class C" ) {}
    void doSomethingInC() {
        logger_.log("C doing something");
    }
private:
  Logger logger_;
};