Using boost::bind with a templated object

Question

I want to pass to boost::bind a templated object, but g++ always yield an error. I have found how to pass a templated function, but is it possible to pass a templated object?.

Here's the code.

#include <boost/thread/thread.hpp>
#include <boost/thread/mutex.hpp>

#include "tbb/tick_count.h"

#include <iostream>
#include <vector>

template<class T>
class LockedVector {
private:
  std::vector<T> v;
  boost::mutex vector_mutex;
public:
  LockedVector(void):v(){}
  LockedVector(const unsigned int& n){
    v.reserve( n );
  }
  void Push(const T& t) {
    boost::mutex::scoped_lock lock( vector_mutex );
    v.push_back(t);
  }
  void Print(std::ostream& O) {
    for(unsigned int i(0);i<v.size();++i){
      O << v[i] << " ";
    }
    std::cout << std::endl;
  }
};

template<class T>
void AddToGlobalVector(LockedVector<T>& lv, unsigned int& start, const unsigned int& end, double& time)  {
  tbb::tick_count t0( tbb::tick_count::now() );
  for(;
  start < end;
  ++start) {
   lv.Push( (T)start );
  }
  time = (tbb::tick_count::now()-t0).seconds();
};

int main(void) {
  double time_t1(0.0);
  double time_t2(0.0);
  LockedVector<unsigned int> global;
  boost::thread t1(&AddToGlobalVector, global, (unsigned int)1, (unsigned int)10, boost::ref(time_t1) );
  boost::thread t2(&AddToGlobalVector, global, (unsigned int)11, (unsigned int)20, boost::ref(time_t2) );
  t1.join();
  t2.join();
  global.Print(std::cout);
  std::cout << "First thread(seconds): " << time_t1 << std::endl;
  std::cout << "Second thread(seconds): " << time_t2 << std::endl; 
}

And here's the g++ output:

main.cpp: In function ‘int main()’:
main.cpp:58: error: no matching function for call to ‘boost::thread::thread(<unresolved overloaded function type>, LockedVector<unsigned int>&, unsigned int, unsigned int, const boost::reference_wrapper<double>)’
/usr/include/boost/thread/detail/thread.hpp:199: note: candidates are: boost::thread::thread(boost::detail::thread_move_t<boost::thread>)
/usr/include/boost/thread/detail/thread.hpp:147: note:                 boost::thread::thread()
/usr/include/boost/thread/detail/thread.hpp:118: note:                 boost::thread::thread(boost::detail::thread_data_ptr)
/usr/include/boost/thread/detail/thread.hpp:108: note:                 boost::thread::thread(boost::thread&)
main.cpp:59: error: no matching function for call to ‘boost::thread::thread(<unresolved overloaded function type>, LockedVector<unsigned int>&, unsigned int, unsigned int, const boost::reference_wrapper<double>)’
/usr/include/boost/thread/detail/thread.hpp:199: note: candidates are: boost::thread::thread(boost::detail::thread_move_t<boost::thread>)
/usr/include/boost/thread/detail/thread.hpp:147: note:                 boost::thread::thread()
/usr/include/boost/thread/detail/thread.hpp:118: note:                 boost::thread::thread(boost::detail::thread_data_ptr)
/usr/include/boost/thread/detail/thread.hpp:108: note:                 boost::thread::thread(boost::thread&)

Thanks.

EDIT:

Well, ok. I have found how to do it.

boost::thread t1(&AddToGlobalVector<unsigned int>, boost::ref(global), (unsigned int)1, (unsigned int)10, boost::ref(time_t1) );
boost::thread t2(&AddToGlobalVector<unsigned int>, boost::ref(global), (unsigned int)11, (unsigned int)20, boost::ref(time_t2) );

Also, I had to move the boost::mutex out of the LockedVector class, since it's not movable and boost::bind complains.

So the question now is if it's possible to maintain the mutex inside the class.

What versions of GCC and Boost are you using? Your code (incorporating your edit) compiled for me using Clang 3.1 (in C++11 mode) and Boost 1.49. You might need to update your tools and Boost library. You should post the errors you're getting instead of just saying "boost::bind complains". How are we supposed to guess what those errors are? — Emile Cormier, Jul 04 '12 at 04:00

score 0 · Accepted Answer · answered Jul 04 '12 at 14:14

0

You may want to declare a move constructor to LockedVector, that instantiates a new mutex instead of trying to move it.

LockedVector(LockedVector<T> && lv) : v(lv.v) {}

Note that I am going fully speculative here, as I don't have access to a compiler.

answered Jul 04 '12 at 14:14

Raphaël Saint-Pierre

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Using boost::bind with a templated object

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