instantiating a new object in cpp

Question

I have 3 classes called Starter,Pizza and Dessert that takes variable number of string inputs whenever an object is created like,

//pizza takes 2 inputs
Pizza p("margarita","large size");

//starter takes 3 inputs
Starter s("ribs","bbq sauce","small size");

But I want to create a new object using a function add() that takes a string and matches it with the class to create a new object. Eg

add(string type)
{
   if(type == "Pizza")
   {
     Pizza *p = new Pizza();
   }

   else if(type == "Starter ")
   {
     Starter *p = new Starter ();
   }
}

Now my question is, how can I give the inputs to the classes in a user friendly way? By user friendly I was thinking that the user can write all the inputs of a class in one line and not using cin to take every single input.

Say we are getting Pizza, then what I dont want,

cout<<"What type of pizza";
cin>>*input* <<endl;
cout<<"What size";
cin>>*input* <<endl;

I want to write all the inputs in one line like,

input "margarita","large"

Answer 1

Credit is to @MuratKarakus. just extending his answer to support this type of input "margarita","large"

// Read complete string.
// Eg. margarita large
string order;
getline(cin, order);

std::replace( order.begin(), order.end(), ',', ' '); // this'll replace all ',' with space

// It automatically parses string based on space
istringstream is(order);
string meal, size;
is >> meal;
is >> size;    

--------update

The code bellow is to support input like "1/2 margarita 1/2 bbq delux", "large"

// Read complete string.
// Eg. margarita large
string order;
getline(cin, order);
std::replace( order.begin(), order.end(), ' ', '-'); // this'll replace all space with '-'
std::replace( order.begin(), order.end(), ',', ' '); // this'll replace all ',' with space
// It automatically parses string based on space
istringstream is(order);
string meal, size;
is >> meal;
std::replace( meal.begin(), meal.end(), '-', ' '); // this'll replace all '-' with space

is >> size;