#include
#include
#include
int main() {
std::vector ivec{1, 2, 3, 4, 5, 6, 7, 6, 5, 4, 3, 2, 1};
std::cout << "take ints as long as they are less than 5: ";
for (auto&& i : iter::takewhile([] (int i) {return i < 5;}, ivec)) {
std::cout << i << ' ';
}
std::cout << '\n';
}