void insert(It b, It e) {
size_t d = std::distance(b, e);
if (d == 1) {
insert(*b);
return;
}
static container merged;
merged.resize(0);
merged.reserve(elements.size() + d);
if (detail::is_sorted(b, e, comp)) {
std::merge(elements.begin(), elements.end(), b, e, std::back_inserter(merged), comp);
}
else {
static container sorted;
sorted.assign(b, e);
std::sort(sorted.begin(), sorted.end(), comp);
std::merge(elements.begin(), elements.end(), sorted.begin(), sorted.end(), std::back_inserter(merged), comp);
}
merged.swap(elements);
iterator it = std::unique(elements.begin(), elements.end());
elements.erase(it, elements.end());
}
void swap( container< A > & l, container< A > & r)
{ l.swap( r); }