The Dark

Inserting elements in the middle of a vector suffers the same problem as deleting elements from the middle - the rest of the vector has to be shuffled around - they are both slow.

Also, appending to the end of a vector may occasionally cause the whole vector to be reallocated and all of the items to be moved. This can be very bad, but using reserve() can help a bit.

std::deque containers are better for when you are continually adding to the end.