RE: [boost] smart ptr changes

From: Jon Kalb (jonkalb_at_[hidden])
Date: 2001-08-17 12:37:57

> -----Original Message-----
> From: Peter Dimov [mailto:pdimov_at_[hidden]] 
> Sent: Friday, August 17, 2001 10:32 AM
> To: boost_at_[hidden]
> Subject: Re: [boost] smart ptr changes
> 
> From: "George A. Heintzelman" <georgeh_at_[hidden]>
> > Why get rid of the std::swap specialization? Although it is 
> > unnecessary for good exception safety, it is going to be 
> faster than 
> > the default version, since you avoid several increments and 
> decrements 
> > of the reference counts (admittedly a compiler can optimize those 
> > away, but why force it to?). Since it is already written and works, 
> > you may as well leave it. There aren't any issues with specializing 
> > this in std::, are there? shared_ptr<x> is a UDT, so it should be 
> > legal...
> 
> A specialization would be legal. However std::swap is a 
> function template and the language does not support partial 
> function template specializations.
> 
> http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/lwg-active.html#226
> http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/papers/2001/n1296.htm

As a boost library it isn't legal, but it could be left in for the
proposal to the LWG. Surely they aren't bound by this.