How can I declare a template pointer without knowing the type?

Question

This is what I would like to do:

ExampleTemplate* pointer_to_template;
cin >> number;
switch (number) {
case 1:
    pointer_to_template = new ExampleTempla         


        

Answer 1

You can do something similar by having your template class derive from a regular class:

#include
#include
using namespace std;

class ExampleBase{

public:
    virtual ~ExampleBase() {}
    virtual string Get() = 0;
};

template
class ExampleTemplate : public ExampleBase{

private:
    T data;

public:
    ExampleTemplate(T t) : data(t){}

    string Get(){        
        stringstream s; s << data;
        return s.str();
    }

};

int main(){

    ExampleBase *base;
    int number;
    cout << "> " << flush; cin >> number;

    switch(number){
        case 1:
            base = new ExampleTemplate(42);
            break;
        case 2:
            base = new ExampleTemplate(3.14);
            break;
        default:
            return 1;
    }

    cout << base->Get() << endl;

    delete base;
    return 0;
}