fibonacci.cpp

generator<pair<int, int>> fibonacci(int n) 
{
    int a = 0;
    int b = 1;
    for ( auto i : ranges::iota_view{1, n+1} ) 
    {
        co_yield make_pair(i, a);           
      
        auto tmp = a;
        a = b;
        b += tmp;
    }
}

int main() 
{
    for( auto p : fibonacci(10) ) 
    { 
        cout << format("{} {}", p.first, p.second) << endl;
    }
}