c++ - 如何创建多个模板对象的数组

Question

我有模板类“工厂”。工厂的原型(prototype)如下:

template <class T>
class Factory
{
    public:
    Factory();
    ~Factory();

    //few more functions & data-members


    private:
    //few more functions & data-members
};

在 main() 中，我制作了多种类型的工厂，如 --

int main()
{
    typedef Factory<int> IntFactory ;
    IntFactory A = IntFactory();

    typedef Factory<float> FloatFactory ;
    FloatFactory B = FloatFactory();

    //Complex is some user defined class
    typedef Factory<Complex> ComplexFactory ;
    ComplexFactory C = ComplexFactory();

    //Point3D is a user defined class
    typedef Factory<Point3D> Point3DFactory ;
    Point3DFactory D = Point3DFactory();

    //I may have several such initializations.

}

问题是如果我想要，我如何制作一个对象数组 A、B、C、D 遍历它们？

Answer 1

我认为你能做的最好的，(在我的脑海中，未经测试)是:

class FactoryBase
{
    public:
        virtual ~FactoryBase() = 0;
};

template <class T>
class Factory : public FactoryBase
{
    //...
};

int main()
{
    std::vector<FactoryBase*> factories;
    factories.push_back(new Factory<int>);
    factories.push_back(new Factory<Complex>);
    //... Make sure you delete these. Better yet, use a smart pointer.
    return 0;
}

请注意指针的 vector，所有 push_back(new ...) 东西都非常容易出现异常和泄漏...