How to avoid laggy resizing of unordered_map during insert

Question

I use unordered_map with MSVC 2010. If I insert many elements into it, it begins to resize. During this process it copies all pairs and rehash them. When there are too many objects it takes too much time. Are there any tips how to avoid this effect? Something like reserve, but it is not implemented n VS 2010

Answer 1

Use rehash instead? It seems to function like reserve