gistfile1.cpp

#include <iostream>
#include <boost/parameter.hpp>

BOOST_PARAMETER_NAME(speed);
BOOST_PARAMETER_NAME(force);
BOOST_PARAMETER_NAME(bar);

struct foo
{
  template <typename ParamMap>
  foo( ParamMap const& opt )
     : speed_( opt[_speed] )
     , force_( opt[_force] )
     , bar_( opt[_bar | true] )
  {}

  float speed_;
  int force_;
  bool bar_;
};

using namespace std;

int main()
{
  {
    foo f((_speed = 8.9f, _bar= false, _force = 5));
    cout << f.speed_ << " " << f.force_ << " " << f.bar_ << "\n";
  }

  {
    foo f((_speed = 8.9f, _force = 5));
	 cout << f.speed_ << " " << f.force_ << " " << f.bar_ << "\n";
  }

  {
	  // uncomment this to get an error
	  //baz b(options[speed = 9.9f, force = 5]);
  }
}