Re: the FOREACH macro

From:
irek.szczesniak@gmail.com
Newsgroups:
comp.lang.c++.moderated
Date:
1 Jan 2007 10:43:23 -0500
Message-ID:
<1167649697.328382.317200@s34g2000cwa.googlegroups.com>
Hi John,

Thanks for your input. However, using std::for_each complicates things
too much: I want to see beneath the FOREACH loop what's happening in my
code and not to read the function object.

Best,
Irek

John L Fjellstad wrote:

irek.szczesniak@gmail.com writes:

Hi,

I would like to do something like this, which is the WISH case:

typedef map<int, double> hash;
hash a;
// ...
FOREACH(a, key, value, hash)
  std::cout << key << "->" << value << "\n";


Would it be easier to use for_each()?

Something like this:
#########
#include <iostream>
#include <map>
#include <cstdlib>

struct PrintOut
{
private:
      int key_;

public:
      PrintOut( int key ) : key_(key) {}

      void operator() ( const std::pair<int, double>& p )
      {
            if (key_ == p.first)
                  std::cout << p.first << "->" << p.second << "\n";
      }
};

int
main()
{
      std::map<int, double> a;

      a.insert( std::make_pair<int,double>(0, 1.71) );
      a.insert( std::make_pair<int,double>(1, 3.14) );

      std::for_each( a.begin(), a.end(), PrintOut(1) );

      return EXIT_SUCCESS;
}
#########

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John L. Fjellstad
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