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Sometimes you need lambda::bind()

Note to self, next time you mix smart pointers and lambda, remember what to do if things don't resolve automatically. Ex.

#include <iostream>
#include <vector>
#include <boost/shared_ptr.hpp>
#include <boost/lambda/lambda.hpp>
#include <boost/lambda/bind.hpp>

using namespace std;
using namespace boost;
using namespace lambda;

struct B {
  explicit B(int a) : a_(a) {}
  int get_a() const { return a_; }
private:
  int a_;
};

ostream& operator << (ostream &s, const B &b)
{
  s << b.get_a();
  return s;
}

int main()
{
  shared_ptr<B> b1(new B(10));
  shared_ptr<B> b2(new B(5));
  vector<shared_ptr<B> > v;
  v.push_back(b1);
  v.push_back(b2);
  for_each(v.begin(),v.end(), cout << *_1 << ' ');
  cout << endl;
  cout << count_if( v.begin(), v.end(), bind(&B::get_a, *_1) > 7);
  return(0);
}

Comments

( 3 comments — Leave a comment )
sjonsvenson
Dec. 1st, 2005 02:09 pm (UTC)
Nope, I don't know that language.
dblume
Dec. 1st, 2005 02:30 pm (UTC)
I don't know if you're being facetious. It is arcane, but it is also clear, concise, and complete. Some people would read this and wonder what a complete n00b I am. Others will read it and find it impenetrable. It's amazing the breadth of skill levels in this discipline.
sjonsvenson
Dec. 2nd, 2005 12:06 am (UTC)
No. I just mean I never learned C or any of it's derivatives/family. I learned to program in Pascal (TP3) and now I program in RPG (in the IBM AS400/eServer).
I can read C and Java but only if it's very simple coding, like one step up from 'hello world'.
( 3 comments — Leave a comment )