rewrite access to collection to avoid “double” finding

Question

I have such code:

std::unordered_map futOrders;

auto i = futOrders.find(orderId);
if (i == futOrders.end()) {
    LimitOrd         


        

Answer 1

How about using size() to realize if an element was inserted, like this:

auto old_size = futOrders.size();
LimitOrder& order = futOrders[orderId];
if (old_size < futOrders.size()) {
    LimitOrder& newOrder = order;
        // work
} else {
    LimitOrder& futOrder = order;
        // another work
}