c++ - 类成员变量的setter怎么写？

Question

我正在尝试用 C++ 为类成员变量编写一个带有 getter 和 setter 的简单类。 setter/getter 工作正常，但我不能写二传手。是否可以用 setter 覆盖“m_var”，或者这是否仅适用于指针变量？

class Foo: public QObject {
Q_OBJECT
public:

MyOtherClass& getVar()  {
    return m_var;
}

private:
  MyOtherClass m_var;
};

Answer 1

应该是这样的:

// this is your setter
// you can set the var parameter as const because it is just copied to var
void setVar(const MyOtherClass& var){m_var = var;}

//this is your getter
MyOtherClass& getVar() {return m_var;}

// also this getter should be declared as const because you return a copy 
// of m_var and thus you do not modify the object
MyOtherClass getVarByCopy() const {return m_var;}

下面的代码可以用 g++ 编译:

class A
{
public :
   int someInt;
};

class B{
    A m_var;
public:
    void setVar(const A& var){m_var = var;}
    A& getVar() {return m_var;}
};

int main(int argc, char* argv[])
{
    B b;
    A a;
    a = b.getVar();
    b.setVar(a);
    return 0;
}