Cannot refer to class template 'data' without a template argument list

I have a public pointer object in a given class

srd::shared_ptr<std::vector<std::vector>> data

I could easily use in a function where I initialize it, but when I am trying to address it in the other fucntion of the same class, Xcode returns ‘Cannot refer to class template ‘data’ without a template argument list’

h:

class Whatever{

   public:

   void setup();
   srd::shared_ptr<std::vector<std::vector<bool>>> data;
 
 }

cpp:

#include "Whatever.h"

void Whatever::setup(){

      data = ... //setting
      for(int i = 0; i < data.get()->size(); i++){
       works here
      }

}

void Whatever::display(){

for(int i = 0; i < data.get()->size(); i++){  // data.get()->size() returns a given error

doesn't work here

}

}

Can anyone help me with that?