Surchage d'opérateur

template

#include <iostream>

class my_vector {
  private:
    int m_data[5];
  public:
    my_vector(){}

    int & operator[] (std::size_t i) {
      return this->m_data[i];
    }

    int operator[] (std::size_t i) const {
      return this->m_data[i];
    }
};

my_vector operator - (
  const my_vector & x,
  const my_vector & y
) {
  my_vector r;
  for (std::size_t i = 0; i < 5; i++) {
    r[i] = x[i] - y[i];
  }
  return r;
}

std::ostream & operator << (
  std::ostream & os,
  const my_vector & x
) {
  os << '[';
  for (std::size_t i = 0; i < 5; i++) {
    os << ' ' << x[i];
  }
  os << " ]";
  return os;
}

int main() {
  my_vector x;
  x[0] = 10;
  x[1] = 20;
  x[2] = 30;
  x[3] = 40;
  x[4] = 50;
  std::cout << "x = " << x << std::endl;

  my_vector y;
  y[0] = 1;
  y[1] = 2;
  y[2] = 3;
  y[3] = 4;
  y[4] = 5;
  std::cout << "y = " << y << std::endl;

  std::cout << "x - y " << (x - y) << std::endl;
  return 0;
}

(mando@velvet) (~) $ g++ vector.cpp 
(mando@velvet) (~) $ ./a.out 
x = [ 10 20 30 40 50 ]
y = [ 1 2 3 4 5 ]
x - y [ 9 18 27 36 45 ]

[]

<<, +, -

<<

std::cout << x