Re: [boost] Cast free NULLs in algorithms

From: David Abrahams (dave_at_[hidden])
Date: 2007-08-01 23:21:56

on Wed Aug 01 2007, Lewis Hyatt <lhyatt-AT-princeton.edu> wrote:

>> On a slightly off-topic but perhaps more interesting note, what's the
>> rationale for having a separate template parameter for the type of the
>> initializing element?  If it used the iterator's value_type (or a
>> reference thereto) then this thread wouldn't be happening.

Good point.  I guess the current way allows more mischief, which might
be intentional.  For example, you could pass an object that, every
time it is converted to int, produces a new random value.

> I think it's because std::iterator_traits didn't exist when the STL
> was first designed. It's similar with accumulate(), you have to pass
> in the starting value so it can grab the type.

You pass the starting value to accumulate so it can grab the value,
not the type.

-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com
The Astoria Seminar ==> http://www.astoriaseminar.com