C++17 STL Cookbook

How to do it...

In this section, we will insert multiple items into an std::map, and use insertion hints for that, in order to reduce the number of lookups.

1. We are mapping strings to numbers, so we need the header files included for std::map and std::string.

      #include <iostream>      #include <map>      #include <string>

2. The next step is to instantiate a map, which already contains some example characters.

      int main()      {          std::map<std::string, size_t> m {{"b", 1}, {"c", 2}, {"d", 3}};

3. We will insert multiple items now, and for each item we will use an insertion hint. Since we have no hint in the beginning to start with, we will just do the first insertion pointing to the end iterator of the map.

          auto insert_it (std::end(m));

4. We will now insert ...