我可以获取为其调用静态方法的类吗? [英] Can I get the class for which a static method was called?

问题描述

这可能是不可能的，但是c ++之前让我感到惊讶，所以去了.

This is probably impossible, but c++ has surprised me before, so here goes.

我有这个基类和三个近似相同的子类:

I have this base class and three near-identical subclasses:

class MyBaseClass {
};

class MyClassX : public MyBaseClass {
public:
    static MyClassX *create() { return new MyClassX(); }
};

class MyClassY : public MyBaseClass {
public:
    static MyClassY *create() { return new MyClassY(); }
};

class MyClassZ : public MyBaseClass {
public:
    static MyClassZ *create() { return new MyClassZ(); }
};

我可以这样称呼他们:

MyClassY *myObjectY = MyClassY::create();

并且我想缩短它，以便基类可以完成工作，而不必为每个子类重复该create()定义.

and I want to shorten that so the base class can do the work, and I don't have to repeat that create() definition for every subclass.

class MyBaseClass {
public:
    template<typename CalledForWhichClass>
    static CalledForWhichClass *create() {
        return new CalledForWhichClass();
    }
};

class MyClassX : public MyBaseClass { };

class MyClassY : public MyBaseClass { };

class MyClassZ : public MyBaseClass { };

但是，使用此设置，我现在必须将其命名为:

however, with this setup, I now have to call it like:

MyClassY myObjectY = MyBaseClass::create<MyClassY>();

但是我想做到这一点，所以我仍然可以像以前那样称呼他们

but I want to make it so I can still call them like I used to:

MyClassY *myObjectY = MyClassY::create();

我希望也许会有这样的黑魔法:

I was hoping perhaps there was some black magic like this:

class MyBaseClass {
public:
    template<typename CalledForWhichClass = __static_context__>
    static CalledForWhichClass *create() {
        return new CalledForWhichClass();
    }
};

有什么想法吗?

推荐答案

如何使用CRTP?

template <typename Derived>
struct BasicMyClass : MyBaseClass {
    static Derived *create() { return new Derived(); }
};

struct MyClassX : public BasicMyClass<MyClassX> {};
struct MyClassY : public BasicMyClass<MyClassY> {);
struct MyClassZ : public BasicMyClass<MyClassZ> {);

您可以使用此模板自动为您创建create成员函数，而不是试图让基类来工作.

Instead of trying to make the base class do the work, you use this template to automatically create the create member function for you.

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