指向具有多个对象的成员函数的指针的向量C ++ [英] Vector of pointers to member functions with multiple objects c++

问题描述

考虑以下代码:

class A
{
public:
    void aFoo() {}
};

class B
{
public:
    void bFoo() {}
};

class C
{
public:
    void c1Foo() {}
    void c2Foo() {}
};

不管代码体系结构如何，即使那些成员函数在多个类中，也可以创建指向成员函数的指针的向量吗?

Regardless the code architecture, is it possible to create a vector of pointers to member functions even if those functions are in multiple classes ?

在这种情况下，继承不是解决方案，因为我们不知道我们要在一个类中使用多少个函数(类C有两个函数).但是我们知道它们都有相同的原型.

In this case, inheritance is not a solution because we don't know how many functions we want to use in a class (class C has two functions). But we know they all have the same prototype.

推荐答案

不同类的成员函数具有不同的类型.因此，为了拥有任何同质容器(例如 std :: vector 或 std :: array )，您需要将它们包装在某种可以表示的值类型中它们全部(例如 boost :: variant 或 boost :: any ).

Member functions of different classes have different types. So in order to have any homogeneous container (like std::vector or std::array) of those you'll need to wrap them in some value type that may represent them all (like boost::variant or boost::any).

另一方面，如果您需要的只是特定类型的成员函数(例如 void())，并且您不介意事先传递应在其上调用它们的对象，那么您就可以将它们存储为 std :: function< void()> (对于此特定示例)，并在对其进行存储之前只调用 std :: bind 容器.

On the other hand if all you need are member functions of a specific type (for example void()) and you don't mind passing the object on which they should be called before hand, then you can just store them as std::function<void()> (for this specific example) and just call std::bind on them before storing them in the container.

作为一个例子，给出:

A a; B b; C c;
std::vector<std::function<void()>> vector {
    std::bind(&A::aFoo, a),
    std::bind(&B::bFoo, b),
    std::bind(&C::c1Foo, c),
    std::bind(&C::c2Foo, c)
};

您可以致电:

for (auto fn : vector)
    fn();

实时演示

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