Re: Iterators and functors

From:
"taylor.hugg@gmail.com" <taylor.hugg@gmail.com>
Newsgroups:
comp.lang.c++
Date:
6 Mar 2007 13:40:16 -0800
Message-ID:
<1173217211.594342.314040@j27g2000cwj.googlegroups.com>
On Mar 6, 3:20 pm, "tryp...@gmail.com" <tryp...@gmail.com> wrote:

Hello all,

I have a question about iterators. I have a container of functors
that operate on an std::string. The functors go something like this:

class Functor {
   std::string operator()(const std::string& s) {/*manipulate
string*/; return newString;}

};

Now, I want to call the functors on a string argument. I write
something like this:

std::vector<Functor> vec;

/*Omitted creation and push_back of a couple Functors */

std::vector<Functor>::const_iterator it = vec.begin();
std::vector<Functor>::const_iterator end = vec.end();

std::string arg("Test argument");

for(; it != end; it++)
   std::cout << *it(arg) << "\n"; //Why doesn't this work?

Instead of using the de-reference operator '*', I have to write the
following:

   it->operator()(arg);

Can some kind soul explain to me why this is? I prefer the cleaner
syntax of the first statement.

-tryptik


well that is a hard question to anser but i think it is wrong

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