[boost] Re: lvalue_cast

From: David Abrahams (dave_at_[hidden])
Date: 2004-09-17 10:10:19

Neal Becker <ndbecker2_at_[hidden]> writes:

> David Abrahams wrote:
>
>> "Neal D. Becker" <nbecker_at_[hidden]> writes:
>> 
>>> This handy little item, lvalue_cast, would make a useful addition to
>>> boost.  I didn't write it, and I don't recall who did.
>> 
>> The problem with that is that casting away the const on a const rvalue
>> is sometimes unsafe.  See the original move semantics proposal for
>> details.
>> 
>
> Not sure what you're saying here.  I agree it can sometimes be unsafe. 
> That's why you shouldn't use it - except when you really want to.  Isn't
> that consistent with the move semantics proposal?

No.  Nothing in the move semantics proposal suggests that the
constness of a const rvalue should be removed.  It only changes const
rvalues into const lvalues.

-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com