C ++方法链接类 [英] C++ Method chaining with classes

问题描述

我试图做方法链接，但是，而不是使用方法在Foo我想要一个类的构造函数（它继承自基类）：

I'm attempting to do method chaining, however, instead of using the Methods in "Foo" I want to a constructor of a class (which is inherited from the base class):

class Bar {

public: 

Bar() {
    std::cout << "This is bar";
}

 };

 class Foo : public Bar {

    public:
    Foo() {
        cout << "This is foo";
    }
 };

所以我的主要看起来像下面这样：

So my main would look like the following:

Foo f = Foo（）。Bar（）;

C ++ 11？还有，有没有一种方法，我可以集成这个标准，或者我必须创建一个方法在Foo调用构造函数Bar？

Why is this not possible in C++/C++11? Also, is there a way in which I can integrate this standard, or would I have to create an method in "Foo" which calls the constructor to "Bar"?

编辑：

class Bar {
public: 
Bar() {
}

Bar& Options() {
    cout << "sf";
    return *this;
}
 };

class Foo : public Bar {

public:
    Foo() {

    }
  }; 

然后在main：

code> Foo F = Foo（）。Options（）;

Foo F = Foo().Options();

推荐答案

问题是非法的，因为 Bar :: Options（）返回对 Bar 的引用，将 Bar 转换为 Foo 对象。

Your updated question is illegal because Bar::Options() returns a reference to a Bar and you don't provide a way to convert a Bar to a Foo object.

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