Re: [Boost-users] Iterating over the output of a member function in std::for_each

1 Mar 2012

      In my specific case there actually ended up being one small
modification I had to make because bind copied the object:

      //  bind version:
      for_each(values.begin(), values.end(),
        bind(boost::ref(avg), bind(&value_wrapper_type::getValue, _1))
      );

Cheers!
Andrew Hundt

On Thu, Mar 1, 2012 at 6:13 PM, Andrew Hundt  wrote:
...
Aha! I had to add:
   typedef void result_type;
to the body of the avg object. Then your example:
   for_each(values.begin(), values.end(),
    bind(avg, bind(&value_wrapper_type::getValue, _1))
   );
Worked perfectly! Thank you very much for the help Mathias, it is
greatly appreciated.
Cheers!
Andrew Hundt
On Thu, Mar 1, 2012 at 2:44 PM, Mathias Gaunard
 wrote:
...
On 03/01/2012 05:52 PM, Andrew Hundt wrote:
...
I have a class with an accessor member function that I want to call and
apply the result to a functor using std::for_each. I have a working
version below that uses a for loop and for_each, but the for_each
version is cryptic and cumbersome. Is there a way I can make the
for_each version more concise?
    #if 0
       // for loop version:
       for(value_vector_type::iterator it = values.begin();
it!=values.end(); it++){
         avg(it->getValue());  // I want to put this in a for_each loop
       }
    #else
      //  bind version:
      std::for_each(values.begin(), values.end(), // iterate over all
values
        boost::bind(
          boost::mem_fn(&average_type::operator()), // attach the
averaging functor to the output of the getvalue call
&avg,
          boost::bind(
            boost::mem_fn(&value_wrapper_type::getValue), // bind the
getValue call to each element in values
            _1
          )
        )
      );
    #endif
for_each(values.begin(), values.end(),
 bind(avg, bind(&value_wrapper_type::getValue, _1))
);
_______________________________________________
Boost-users mailing list
Boost-users@lists.boost.org
http://lists.boost.org/mailman/listinfo.cgi/boost-users