temporary objects are not allowed to be pass by ref anymore

[Michel Fortin]

On 2009-04-19 15:52:02 -0400, Andrei Alexandrescu 
<SeeWebsiteForEmail at erdani.org> said:

> Now onto why ref was disallowed to bind to an rvalue. This is because 
> some functions take things by ref intending to change them.

True.


> Passing an rvalue is in such cases a bug.

I disagree. Function modify the temporary value, then the value is 
forgotten. It's just like calling a function and ignoring the returned 
value. It could be a bug, but it may not.

For instance, a function may just be performing some destructive 
operation on the argument, in which case a temporary rvalue may 
very-well be appropriate since you are unlikely to need the result 
afterwards.

Even C++0x saw the need and added rvalue non-const reference.
<http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1690.html>


-- 
Michel Fortin
michel.fortin at michelf.com
http://michelf.com/