Consider number.cc. It creates a class called Number thats a wrapper around an int.

1) How is it that << works for Number, even though operator<< wasnt defined for this class?

2) Consider operator>>. It doesnt check for failure. And, yet, it works properly for: valid numeric input, end of input, incorrect input. How can this be?

3) Now, improve operator>> so that it works properly for input such as one, two, three, four, and five, as well as working for all traditional numeric input that worked before. Consider using ios::clear

#include  #include  using namespace std; class Number { public: Number() = default; Number(const Number &) = default; Number(int v) : value(v) {} Number &operator=(int n) { value = n; return *this; } operator int() const { return value; } private: int value = 0; // default value unless otherwise given }; istream &operator>>(istream &is, Number &rhs) { int n; is >> n; rhs = n; return is; } int main() { Number n = 666; istringstream ss("12 34 three 789 five"); while (ss >> n) cout << n << ' '; cout << ' '; }