使用 c++11 优化扩展上述答案:
#include <utility>
template<class Iter>
struct range_t : public std::pair<Iter, Iter> {
using pair_t = std::pair<Iter, Iter>;
range_t(pair_t&& src)
: std::pair<Iter, Iter>(std::forward<pair_t>(src))
{}
using std::pair<Iter, Iter>::first;
using std::pair<Iter, Iter>::second;
Iter begin() const { return first; }
Iter end() const { return second; }
};
template<class Iter>
range_t<Iter> range(std::pair<Iter, Iter> p) {
return range_t<Iter>(std::move(p));
}
template<class Iter>
range_t<Iter> range(Iter i1, Iter i2) {
return range_t<Iter>(std::make_pair(std::move(i1), std::move(i2)));
}
// TEST:
#include <iostream>
#include <set>
using namespace std;
int main() {
multiset<int> mySet { 6,4,5,5,5,3,3,67,8,89,7,5,45,4,3 };
cout << "similar elements: ";
for (const auto&i : range(mySet.lower_bound(5), mySet.upper_bound(10))) {
cout << i << ",";
}
cout << "\n";
int count = 0, sum = 0;
for (const auto& i: range(mySet.equal_range(5)))
{
++count;
sum += i;
}
cout << "5 appears " << count << " times\n"
<< "the sum is " << sum << "\n";
return 0;
}