Question

I am making a command prompt in C++. I would like a user to enter a line such as “say something”. This will then be split up so that “say” would be the command name and “something” would be a parameter. So far, so good – this is already working.

I would then like to use the name of the command to call the appropriate method. I could use some kind of look-up table but is there a better method?

Answer 1

probably you need something like map of command keywords and function or method pointers

#include <string>
#include <map>

class CmdHandler // our handler class
{
public:
    void Handler(const std::string &arg){}//our handler method
};


typedef void (CmdHandler::*MethodPtr)(const std::string &); // make typedef to easily deal with the type of the member-function pointer

std::map<std::string, MethodPtr> my_handlers; // make our method lookup table

int _tmain(int argc, _TCHAR* argv[])
{
    CmdHandler handler;
    //add a real member-function pointer for the "say" command
    my_handlers.insert(std::make_pair("say", &CmdHandler::Handler));

    //look for the handler of command "say" and call it instantly 
    (handler.*my_handlers["say"])("something");
    return 0;
}