[x265] use std::swap() for readability

[Steve Borho]

On Wed, Jul 9, 2014 at 7:59 AM, Derek Buitenhuis
<derek.buitenhuis at gmail.com> wrote:
> On 7/9/2014 11:16 AM, Deepthi Nandakumar wrote:
>> We spent a bunch of effort last year to remove STL dependencies, since they cause serious trouble between different compilers (even between different compiler versions).  This is especially since a lot of users will use x265 as a static library.
>
> I tried to ask about this before to no avail: What compilers and how?
>
> STL portability has not been an issue for a very long time.

In particular between Intel C++ and MSVC on Windows.

FWIW, I believe STL is safe so long as you only use the portions that
are header based; and std::swap() is likely such a function.
Different implementations of std::swap are unlikely to cause link
issues.

-- 
Steve Borho