#include
#include
#include
bool greater_than_four(int i) {
return i > 4;
}
class LessThanValue {
private:
int compare_val;
public:
LessThanValue() = delete;
LessThanValue(int v) : compare_val(v) { }
bool operator() (int i) {
return i < this->compare_val;
}
};
int main() {
std::vector ns{1, 5, 6, 0, 7, 2, 3, 8, 3, 0, 2, 1};
std::cout << "ns = { ";
for (auto&& i : ns) {
std::cout << i << ' ';
}
std::cout << "}\n";
std::cout << "Greater than 4 (function pointer)\n";
for (auto&& i : iter::filter(greater_than_four, ns)) {
std::cout << i << '\n';
}
std::cout << "Less than 4 (lambda)\n";
for (auto&& i : iter::filter([] (const int i) { return i < 4; }, ns)) {
std::cout << i << '\n';
}
LessThanValue lv(4);
std::cout << "Less than 4 (callable object)\n";
for (auto&& i : iter::filter(lv, ns)) {
std::cout << i << '\n';
}
// filter(seq) with no predicate uses the truthiness of the values
std::cout << "Nonzero ints filter(ns)\n";
for (auto&& i : iter::filter(ns)) {
std::cout << i << '\n';
}
std::cout << "odd numbers\n";
for (auto&& i : iter::filter([] (const int i) {return i % 2;}, ns)) {
std::cout << i << '\n';
}
}