[boost] Re: Formal Review: FOREACH macro

From: Eric Niebler (eric_at_[hidden])
Date: 2005-05-02 13:40:12

Peter Dimov wrote:
> Peter Dimov wrote:
> 
>> Eric Niebler wrote:
>>
>>> Yes, but I was refering to native (C-style) strings, as in:
>>> BOOST_FOREACH(char ch, "hello world")
>>
>>
>> This is a good opportunity to ask: what does this do?
>>
>> char const a[] = { 0, 1, 2 };
> 
> 
> Or for extra fun, drop the 0.
> 
>> BOOST_FOREACH( int x, a )
>> {
>>    std::cout << x << std::end;
>> }
> 

The short answer is: it is consistent with how Boost.Range handles it. 
The longer answer is that it is treated as a null-terminated string. In 
the first case, the loop immediately terminates and in the second, 
behavior is undefined -- you read off the end of the array because it is 
not null-terminated.

I think this is OK. If you think this is a problem, you should discuss 
it with Thorsten. Whatever we decide, FOREACH and Range should be 
consistent.

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