Re: How to call a function just using a string?

From:
terminator <farid.mehrabi@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Thu, 6 Dec 2007 10:00:13 -0800 (PST)
Message-ID:
<e82214e3-9c9b-4b9a-b876-8521cd0b68df@e25g2000prg.googlegroups.com>
On Dec 6, 7:11 am, moxemer...@gmail.com wrote:

Dear Terminator,
I find your code to be quite enthralling, however, I do not understand
the bulk of it. =(

Could you comment out your lines so that I understand what is going
on.


We need a global mapper object that maps every desired function to a
string , but global objects couse some troubles in initialization ,so
we need some tricks.

I wrote:

#include <map>
#include <string>

typedef std::map<std::string,void(*)(void)> FuncMapTypeBase;


// define a class in order to initialize a static object.

struct FuncMapType :


/*
   inherit from the type that is intended to be used for the static
object:
*/

   FuncMapTypeBase
{

/*
   define the initializer code for the static object:
*/

   FuncMapType(){
      (*this)["fun1"]=&fun1;
      (*this)["fun2"]=&fun2;
      (*this)["fun3"]=&fun3;
   }

};


/*
  define a static-object-wrapper to make sure the static object is
well constructed before first use:
*/

const FuncMapType &funxns(){

/*
   map every function to a string so that you can find it via the
string:
*/

   static FuncMapType funcs;
   return funcs;

};


//just what the OP wanted:

void funcall(const std::string& str){


// call function pointer 'key'ed by 'str':

  (*(funcxns()[str]))();

};


Is it undersandable now?

regards,
FM.

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