* Write a program to illustrate how to define and declare a class template for reading two data items from the keyboard and to find their sum.

#+ATTR_LATEX: :options frame=single,breaklines=true
#+begin_src cpp :tangle 25.cpp :wrap src text
#include <iostream>
using namespace std;

template <typename T,
          typename = enable_if_t<std::is_arithmetic<T>::value, T>>
class Foo {
  T x, y;

public:
  Foo() {
    cout << "x: ";
    cin >> x;
    cout << "y: ";
    cin >> y;
  }

  T sum() { return x + y; };
};

int main() {
  Foo<float> bar;

  cout << bar.sum();

  return 0;
}
#+end_src

#+begin_src text
x: 4.3
y: 9.1
13.4
#+end_src

#+LATEX: \clearpage

* Write a program to demonstrate the use of special functions, constructor and destructor in the class template. The program is used to find the biggest of two entered numbers.

#+ATTR_LATEX: :options frame=single,breaklines=true
#+begin_src cpp :tangle 26.cpp :wrap src text
#include <iostream>
using namespace std;

template <typename T,
          typename = std::enable_if_t<std::is_arithmetic<T>::value, T>>
class Foo {
  T x, y;

public:
  Foo() {
    cout << "x: ";
    cin >> x;
    cout << "y: ";
    cin >> y;
  }

  ~Foo() { cout << "Destructor called, nothing to do here."; }

  T mx() { return (x > y ? x : y); };
};

int main() {
  Foo<float> bar;

  cout << bar.mx() << endl;

  return 0;
}
#+end_src

#+begin_src text
x: 3.4
y: 9.1
9.1
Destructor called, nothing to do here.
#+end_src

#+LATEX: \clearpage

* Write a program to illustrate how template functions can be overloaded.

#+ATTR_LATEX: :options frame=single,breaklines=true
#+begin_src cpp :tangle 27.cpp :wrap src text
#include <fstream>
#include <iostream>

using namespace std;
const string FILE_PATH = "./27.out";

int main() {
  string line;

  cout << "Running program till the string \"EOH\" is received via stdin"
       << endl;

  ofstream file(FILE_PATH);

  file.close();
  file.open(FILE_PATH, ios_base::app);

  while (getline(cin, line)) {
    if (line == "EOH")
      break;
    file << line << endl;
  }

  return 0;
}
#+end_src

#+begin_src text
Running program till the string "EOH" is received via stdin
i have a
flayed dismembered
corpse in front of my
lawn
EOH
#+end_src