Question

How to process dynamic source code in C++? Is it possible to use something like eval(“foo”)?

I have some functions that need to be called depending on user’s choice:

     void function1 ();
     void function2 ();
     ...
     void functionN ();

     int main (int argv, char * argv [])
     {
         char * myString = new char [100];
         ...
         myString = "1" //user input            
         cout << eval("function"+myString)();
     }

How is it usually done?

UPD: Based on slacy’s and clinisbut’s answers I think I need to make a function registry. I suppose it should be made as an array of pointers to functions. Here’s the question, how do I declare an array of pointers to functions?

Answer 1

C++ is a compiled language, and thus, there is no equivalent to “eval()”.

For the specific example you mention, you could make a function registry that maps inputs (strings) to outputs (function pointers) and then call the resultant function.

There are several C++ interpreter libraries that are available, although performance will be very poor, they may accomplish what you want. Google search for “C++ interpreter”. I’ve seen results for “Ch“, “CINT” and “clipp”