lst-0058-book.cpp
// https://godbolt.org/z/Gfazq6GE7
#include <generator>
#include <iostream>
#include <vector>
std::generator<int> fib(int n) { // generates int values
int a = 0, b = 1;
while (--n) {
co_yield b; // makes this function a coroutine
auto tmp = a;
a = b;
b += tmp;
}
}
int main() {
for (auto i : fib(10)) std::cout << i << ' ';
std::cout << '\n'; // Output: 1 1 2 3 5 8 13 21 34 55
}