Re: [Boost-users] [Range] Single Pass Range functionality

Subject: Re: [Boost-users] [Range] Single Pass Range functionality
From: Edward Diener (eldiener_at_[hidden])
Date: 2009-02-23 08:02:42

Thorsten Ottosen wrote:
> Edward Diener skrev:
>> In the Boost Range documentation describing the Range concepts for a 
>> single pass range it lists in the expression semantics post-condition 
>> for boost::begin(a):
>>
>> "boost::begin(a) is either dereferenceable or past-the-end. It is 
>> past-the-end if and only if boost::distance(a) == 0."
>>
>> However the documentation for single pass range does not list 
>> boost::distance as a valid expression nor in the reference section is 
>> boost::distance listed as a single pass range function.
>>
>> Is boost::distance a valid function when applied to a single pass range ?
> 
> Yes. boost::distance() is specified in terms of std::distance().

OK. I think the Range documentation should be updated to reflect that. 
The implications of the Range documentation are currently that 
boost::distance is valid only for Forward Range on up.