[boost] Re: lvalue_cast

From: David Abrahams (dave_at_[hidden])
Date: 2004-09-15 20:12:44

Rob Stewart <stewart_at_[hidden]> writes:

> From: "Neal D. Becker" <nbecker_at_[hidden]>
>> 
>> 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.
>> 
>> template<class T>
>> inline T& lvalue_cast (const T& rvalue) {
>>   return const_cast<T&> (rvalue);
>> }
>
> That's just a different spelling of const_cast.  To make it
> useful, you need to make it more generic:
>
>    template <typename T>
>    inline T &
>    lvalue_cast(T & value_i)
>    {
>       return value_i;
>    }
>
> That, of course, permits you to silently cast away the const-ness
> of const lvalues.  

That's news to me.  AFAICT it's totally safe, but it doesn't work
with rvalues, which sort of undermines the whole thing.

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