--- /dev/null
+// $Id$
+//
+// Copyright (C) 2007
+// Fraunhofer Institute for Open Communication Systems (FOKUS)
+// Competence Center NETwork research (NET), St. Augustin, GERMANY
+// Stefan Bund <g0dil@berlios.de>
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the
+// Free Software Foundation, Inc.,
+// 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+/** \file
+ \brief Definitions internal header */
+
+#ifndef IH_SENF_Utils_Logger_Definitions_
+#define IH_SENF_Utils_Logger_Definitions_ 1
+
+// Custom includes
+
+///////////////////////////////ih.p////////////////////////////////////////
+
+// Implementation details concerning SENF_LOG_CLASS_AREA
+//
+// The SENF_LOG_CLASS_AREA statement shall declare the containing class as it's own default area. Of
+// course, we cannot make the containing class into an area. Therefor we need to trick around a bit:
+//
+// We begin by defining an area SENFLogArea with in the class. This area however is hacked, so that
+// it's name() member will return the name of the containing class (which is simple: just cut of the
+// last couple of characters of the name since the name will always end in '::SENFLogArea').
+//
+// This however does not allow the use of the containing class as an area. There are several places
+// which need to be adjusted to allow using the containing class as an area: The logging statements
+// (SENF_LOG), the compile time configuration via SENF_LOG_CONF and the runtime configuration via
+// route statements.
+//
+// Lets begin with the compile time configuration. The compile time configuration is done using
+// specialization of the senf::log::detail::Config template. This doesn't care, what the area
+// template argument really is. Therefore, compile-time configuration just uses the containing class
+// as is. So we need to make sure, that the logging statements use the containing class when
+// checking the compile-time limit whereas they need to use the nested SENFLogArea when calling the
+// targets.
+//
+// So let's look at the logging statements. The central logic for parsing the logging parameters is
+// in SENF_LOG_MERGE_PARAMETERS in Parameters.ih. Here we have a special case which detects classes
+// with a SENFLogArea member and then set's things up correctly: It uses the containing class for
+// compile time checking (this is, what 'area_base' typedef is for) while using the nested
+// SENFLogArea for routing (this is, what the 'area' typedef is for).
+//
+// So the last thing which needs to be adjusted is the routing which is part of the Target
+// class. Here for each template taking an area as an argument we really provide TWO templates, one
+// taking the area directly, the other checking for a nested SENFLogArea member. We can
+// differentiate these overloads using boost::enable_if and friends.
+//
+// This setup makes a class with SENF_LOG_CLASS_AREA() look like an ordinary area even though the
+// implementation is somewhat different.
+
+#define SENF_LOG_DEFINE_AREA_I(area, decls) \
+ struct area \
+ : public senf::log::detail::AreaBase, public senf::singleton<area> \
+ { \
+ static std::string name() { return instance().v_name(); } \
+ using senf::singleton<area>::instance; \
+ decls \
+ private: \
+ area() { init(); } \
+ friend class senf::singleton<area>; \
+ }
+
+namespace senf {
+namespace log {
+namespace detail {
+
+ /// Internal: Alias base class
+ struct AliasBase {};
+
+}}}
+
+///////////////////////////////ih.e////////////////////////////////////////
+#endif
+
+\f
+// Local Variables:
+// mode: c++
+// fill-column: 100
+// comment-column: 40
+// c-file-style: "senf"
+// indent-tabs-mode: nil
+// ispell-local-dictionary: "american"
+// compile-command: "scons -u test"
+// End:
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