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

Assuming there is a way to "determine if an order is empty", you could do:

LimitOrder& anOrder = futOrders[orderId];

if (anOrder.empty())       
{
   // New order, do stuff that only new orders need. 
}
else
{
   // Old order, update it.
}

The empty method could of course be something like if (anOrder.name == "") or if (anOrder.orderId == 0), etc.