Use mapped lambdas for a jump table

A jump table is a useful pattern when you want to select an action from a user or other input. Jump tables are often implemented in if/else or switch structures. In this recipe, we'll build a concise jump table using only an STL map and anonymous lambdas.

How to do it…

It's easy to build a simple jump table from a map and lambdas. The map provides simple indexed navigation and the lambda can be stored as payload. Here's how to do it:

• First, we'll create a simple prompt() function to get input from the console:

  const char prompt(const char * p) {
      std::string r;
      cout << format("{} > ", p);
      std::getline(cin, r, '\n');
      if(r.size() < 1) return '\0';
      if(r.size() > 1) {
          cout << "Response too long...