如何在C ++ 11中存储任意方法指针? [英] How to store arbitrary method pointers in c++11?

问题描述

我需要一种存储方法指针列表的方法，但是我不在乎它们属于什么类.我想到了这一点:

I need a way to store a list of method pointers, but I don't care about what class they belong to. I had this in mind:

struct MethodPointer
{
    void *object;
    void (*method)(void);
};

然后我可以有一个采用任意方法的函数:

Then I could have have a function which takes an arbitrary method:

template <typename T>
void register_method(void(T::*method)(void), T* obj) {
    MethodPointer pointer = {obj, method);

}

void use_method_pointer() {
    ...
    MethodPointer mp = ...

    // call the method
    (mp.object->*method)();

    ...
}

这显然无法编译，因为我无法在register_method()中将方法指针转换为函数指针.

This obviously doesn't compile because I can't convert the method pointer into a function pointer in register_method().

之所以需要它，是因为我有一个可以发出事件的类-我想让任意实例将这些事件作为方法调用进行订阅.这可能吗?

The reason I need this is because I have a class which can emit events - and I want arbitrary instances to subscribe to these events as method calls. Is this possible to do?

PS.适用条件: 1.我不想使用Boost 2.我不想使用监听器"接口，订户必须将抽象接口类作为子类.

PS. Conditions apply: 1. I don't want to use Boost 2. I don't want to use a 'Listener' interface, where a subscriber have to subclass an abstract interface class.

谢谢您的时间.

推荐答案

我相信您只是在寻找 std::function :

I believe you are just looking for std::function:

using NullaryFunc = std::function<void()>;

注册:

template <typename T>
void register_method(void(T::*method)(void), T* obj) {
    NullaryFunc nf = std::bind(method, obj);

    // store nf somewhere  
}

用法:

void use_method() {
    ...
    NullaryFunc nf = ...;
    // call the function
    nf();
    ...
}

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