[asio-users] Using C++11/Boost standard synchronization implementations

[Tatsuyuki I. <ish...@gm...>]

I think it's definitely better to use <thread>, <mutex>, <atomic> or the
equivalent functions in Boost instead of a custom implementation.

Some points:
1. They're precompiled system libraries, while asio is commonly used as
header-only. Using system libraries also reduce the redundant header
inclusions.
2. Less things to manage.
3. std looks better in debugger.