er's logger class, the threading model and the list of the required features. The former three parameters are passed to the <code class="computeroutput"><a class="link" href="basic_logger.html" title="Class template basic_logger">basic_logger</a></code> class template. The feature list must be an MPL type sequence, where each element is a unary MPL metafunction class, that upon applying on its argument results in a logging feature class that derives from the argument. Every logger feature provided by the li