[Boost-users] Generalize boost::optional as boost::range to support boost::range::adaptors

Subject: [Boost-users] Generalize boost::optional as boost::range to support boost::range::adaptors
From: bradphelan_at_[hidden]
Date: 2010-06-03 08:52:29

Hi all,

I've implemented a small adaptor to make boost::optional behave like a
range. This extends the functionality of boost::optional to be more
like the scala Option class and the haskell Maybe monad.

A trivial motivating example is

int plus(const int & i){
   return i + 1;
}

void foo(boost::optional<int> opt_v){
   boost::copy
       ( opt_v | boost::adaptors::transformed(plus)
       , std::ostream_iterator<int>(std::cout)
       );
}

foo(10)

outputs

11

The full implementation and details are at

http://xtargets.heroku.com/2010/06/03/using-boostoptional-as-a-range/

Does anybody think this is a useful extension to boost::optional or
would be willing to provide feedback or suggestions on the
implementation.

Regards

Brad