[boost] Re: copy_on_write

From: Maksym Motornyy (mmotorny_at_[hidden])
Date: 2005-05-31 10:27:20

> There's a pretty nice implementation of COW objects in the Adobe Open
> Source library (http://opensource.adobe.com).  You might take a look
> at that.
I saw it. Honestly, after I implemented COW myself :) Do you want to say 
it's no sence to double existing things?

> A compiler
> that implements NRVO (Named Return Value Optimization) can return an
> object (essentially) by const reference without any special COW
> wrapper classes.  
Agree, this is not the best example for such a compiler. AFAIK VC++ 
doesn't implement this optimization.

> Also, some C++ Standard Library implementations use
> a reference-counted std::string implementation, so this extra effort
> would be wasted.
STLport and Dinkumware (I suppose most widely used) doesn't belong to 
that implementations. That's why personally I require COW-wrapper.