[boost] Re: BOOST_FOREACH and break

From: Eric Niebler (eric_at_[hidden])
Date: 2004-07-23 11:55:20

Rozental, Gennadiy wrote:
> Hi,
> 
> I am trying to use construct similar to BOOST_FOREACH macro. In many cases I
> need to be able to detect whether loop was aborted with break or not.
> 
> BOOST_FOREACH( ... ) 
> {
> }
> 
> // here
> if( aborted ) {
> ....
> }
> else {
> }
> 
> Is there way to do so?
> 

There is a hidden variable in BOOST_FOREACH that tracks this 
information, but it is scoped, so you can't get at it. (And rightly so; 
the scoping of hidden control variables is what makes BOOST_FOREACH 
well-behaved.)

You would have to do it like this:

bool aborted = false;

BOOST_FOREACH( ... )
{
     aborted = true;

     // your code here which could break

     aborted = false;
}

if( aborted ) ...

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com