Re: [boost] Improving the assignment operators of various Boost types

Subject: Re: [boost] Improving the assignment operators of various Boost types
From: David Abrahams (dave_at_[hidden])
Date: 2008-09-10 14:53:02

on Wed Sep 10 2008, Andrey Semashev <andrey.semashev-AT-gmail.com> wrote:

> One downside is that self-assignment is made suboptimal. My typical operator=
> implementation is:
>
>   T& operator= (T const& that)
>   {
>     if (this != &that)
>       T(that).swap(*this);
>     return *this;
>   }
>
> Not sure, however, if it is critical enough.

IMO it is not only non-critical, but the extra little bit of complexity
involved in worrying about self-assignment is slightly dangerous, and it
pessimizes the usual case (non-self-assignment) by adding a test and
branch.

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com