[boost] [function] Anything to adapt a boost::function object?

From: Chris Uzdavinis (chris_at_[hidden])
Date: 2006-04-20 15:16:12

Hi, I have an idea of something, and am not sure if Boost provides it.
In short, I'd like an adapter object that "wraps" a boost::function
object, and changes the interface such that all the N arguments are
taken as strings, automatically converted (using lexical_cast?) to the
proper types, and then invoke the boost::function object passsing in
those parameters.

For example, I envision something like this:

  #include "boost/function.hpp"
  #include <iostream>
  
  void func(int i, char c) 
  { 
    std::cout << "f called with " << i << " and " << c << std::endl;
  }
  
  
  int main()
  {
    boost::function<void(int, char)> f;
    f = &func;
  
    // I'm wanting something like this.
    boost::function_string_adapter str_f(f);

    // call func() but pass string args instead of int,char
    str_f("123", "x"); // invokes f(123i, 'x') 
  }
  
The magic is that boost::function knows the proper types, so the
adapter could ask it to what type each string needs to be converted,
then it could do a lexical_cast to get the value.

My motivation for wanting this is to implement a "simple" command
interpreter for a socket-based administrative interface.  I
pre-register a bunch of function objects, then whenever someone sends
a command down the socket, it arrives as a string.  The function
object is looked up by name, and then the call-operator is invoked
given the string arguments.  Internally, the proper string-to-type
converstions occur, and the boost::function is called with those
values.  (If the conversion fails, an exception would be perfectly
reasonable.)

Is this possible with anything in boost?  Would the idea I show
above be a good way to go, or might boost::function be the wrong
approach?

Thanks in advance!

-- 
Chris