#include <cassert>
#include <stdexcept>
#include <vector>

int main() {
    std::vector<int> values{4, 8, 12};
    assert(values.at(2) == 12);
    bool rejected = false;
    try {
        (void)values.at(values.size());
    } catch (const std::out_of_range&) {
        rejected = true;
    }
    assert(rejected);
    assert(values.size() == 3 && values.at(0) == 4);
}