[move] move in range for

[qqiangwu]

void foo(std::vector<std::unique_ptr<int>>& cont, std::unique_ptr<int>& p)
{
 for (auto& x : cont) {
 p = std::move(x);
 }

 for (auto& x: cont) {
 use(x);
 }
}

void bar(std::vector<std::unique_ptr<int>>& cont, std::unique_ptr<int>& p)
{
 for (size_t i = 0; i < cont.size(); ++i) {
 p = std::move(cont[i]);
 }

 for (auto& x: cont) {
 use(x);
 }
}