CODEWITHSUNDEEP
c++classtemplatesobjecttypes
Koborl
Koborl

Reputation: 235

C++ Template, Declaring Object without Initialising

so i have the following situation. Basically i want to know if it's possible to declare an object of a template class without knowing it's type, or is there another approach i can use for a situation like this.

template <class T> class SomeTemplateClass{
    vector<T> v;
}

int main(){
  --- Here is where i want to declare the object ---
  SomeTemplateClass o;
  cin >> eType;
  --- Type is not determined until some user input---
  if (eType == "int"){
        o = SomeTemplateClass<int> (size);
  } 
  else if (eType == "char") {
      o = SomeTemplateClass<char> (size);
  }
  else if (eType == "float") {
     o = SomeTemplateClass<float> (size);
  }

The type has to be passed as standard input as this is a requirement of the assignment.

EDIT: Ignoring everything else, my problem is that i want to create a vector of type T where T is determined at run-time via user-input. Is this possible at all, and if not what is an acceptable solution

Upvotes: 0

Views: 103

Answers (1)

user2487382
user2487382

Reputation:

Well, from reading your comment I figured out you'd want something like that

template<typename T>
class myclass {
    vector<T> v;
... other methods
};

template<typename T>
void do_something_cool_with_myclass(myclass<T> obj)
{
   //do something with obj, type independently
}

int main() {
    ...
    cin >> type; //get type from user somehow
    switch (type) {
        case int:
         myclass<int> obj;
         do_something_cool_with_myclass<int>(obj);
        ....
    }
}

You don't waste memory and can process your data without knowing it's type on compile time.

Upvotes: 1

Related Questions