Question

recently I’ve been reading through Scott Meyers’s excellent Effective C++ book. In one of the last tips he covered some of the features from TR1 – I knew many of them via Boost.

However, there was one that I definitely did NOT recognize: tr1::reference_wrapper.

How and when would I use tr1::reference_wrapper?

Answer 1

It’s like boost::ref, as far as I know. Basically, a reference which can be copied. Very useful when binding to functions where you need to pass parameters by reference.

For example (using boost syntax):

void Increment( int& iValue ) {     iValue++; }  int iVariable = 0; boost::function< void () > fIncrementMyVariable = boost::bind( &Increment, boost::ref( iVariable ));  fIncrementMyVariable(); 

This Dr. Dobbs article has some info.

Hope this is right, and helpful. 🙂