std::map unable to handle polymorphism?

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时光说笑 2021-01-18 23:38

When using std::map in c++, is it possible to store inherited classes as their \"base class\" in the map and still being able to call their overloaded methods? See this exam

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小蘑菇 (楼主)

2021-01-19 00:18
First idea is that to get polymorphism you need to call member method on pointer or reference. I would store pointer to base class in the map (the element that you store gets copied) and then call via pointer like this:
```
#include 
#include 

class Base
{
    public:
    virtual void Foo() { std::cout << "1"; }
};

class Child : public Base
{
    public:
    void Foo() { std::cout << "2"; }
};

int main (int argc, char * const argv[])
{
    std::map Storage;
    Storage["rawr"] = new Child();
    Storage["rawr"]->Foo();
    return 0;
}
```
You get result "2".

Note: You have to take care of the allocated memory now.
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