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diff --git a/boost/log/utility/strictest_lock.hpp b/boost/log/utility/strictest_lock.hpp
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+/*
+ *          Copyright Andrey Semashev 2007 - 2014.
+ * Distributed under the Boost Software License, Version 1.0.
+ *    (See accompanying file LICENSE_1_0.txt or copy at
+ *          http://www.boost.org/LICENSE_1_0.txt)
+ */
+/*!
+ * \file   utility/strictest_lock.hpp
+ * \author Andrey Semashev
+ * \date   30.05.2010
+ *
+ * The header contains definition of the \c strictest_lock metafunction that
+ * allows to select a lock with the strictest access requirements.
+ */
+
+#ifndef BOOST_LOG_UTILITY_STRICTEST_LOCK_HPP_INCLUDED_
+#define BOOST_LOG_UTILITY_STRICTEST_LOCK_HPP_INCLUDED_
+
+#include <boost/mpl/integral_c.hpp>
+#include <boost/log/detail/config.hpp>
+#include <boost/log/detail/locks.hpp>
+#if defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+#include <boost/preprocessor/cat.hpp>
+#include <boost/preprocessor/arithmetic/sub.hpp>
+#include <boost/preprocessor/arithmetic/inc.hpp>
+#include <boost/preprocessor/arithmetic/dec.hpp>
+#include <boost/preprocessor/repetition/enum_trailing.hpp>
+#include <boost/preprocessor/repetition/enum_params_with_a_default.hpp>
+#include <boost/log/detail/pp_identity.hpp>
+#endif
+#if defined(BOOST_LOG_BROKEN_CONSTANT_EXPRESSIONS)
+#include <boost/mpl/less.hpp>
+#endif
+#include <boost/log/detail/header.hpp>
+
+#ifdef BOOST_HAS_PRAGMA_ONCE
+#pragma once
+#endif
+
+#if defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+#if !defined(BOOST_LOG_STRICTEST_LOCK_LIMIT)
+/*!
+ * The macro defines the maximum number of template arguments that the \c strictest_lock
+ * metafunction accepts. Should not be less than 2.
+ */
+#define BOOST_LOG_STRICTEST_LOCK_LIMIT 10
+#endif // BOOST_LOG_STRICTEST_LOCK_LIMIT
+#if BOOST_LOG_STRICTEST_LOCK_LIMIT < 2
+#error The BOOST_LOG_STRICTEST_LOCK_LIMIT macro should not be less than 2
+#endif
+#endif // defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+
+namespace boost {
+
+BOOST_LOG_OPEN_NAMESPACE
+
+//! Access modes for different types of locks
+enum lock_access_mode
+{
+    unlocked_access,    //!< A thread that owns this kind of lock doesn't restrict other threads in any way
+    shared_access,      //!< A thread that owns this kind of lock requires that no other thread modify the locked data
+    exclusive_access    //!< A thread that owns this kind of lock requires that no other thread has access to the locked data
+};
+
+//! The trait allows to select an access mode by the lock type
+template< typename LockT >
+struct thread_access_mode_of;
+
+template< typename MutexT >
+struct thread_access_mode_of< no_lock< MutexT > > : mpl::integral_c< lock_access_mode, unlocked_access >
+{
+};
+
+#if !defined(BOOST_LOG_NO_THREADS)
+
+template< typename MutexT >
+struct thread_access_mode_of< lock_guard< MutexT > > : mpl::integral_c< lock_access_mode, exclusive_access >
+{
+};
+
+template< typename MutexT >
+struct thread_access_mode_of< unique_lock< MutexT > > : mpl::integral_c< lock_access_mode, exclusive_access >
+{
+};
+
+template< typename MutexT >
+struct thread_access_mode_of< shared_lock< MutexT > > : mpl::integral_c< lock_access_mode, shared_access >
+{
+};
+
+template< typename MutexT >
+struct thread_access_mode_of< upgrade_lock< MutexT > > : mpl::integral_c< lock_access_mode, shared_access >
+{
+};
+
+template< typename MutexT >
+struct thread_access_mode_of< boost::log::aux::exclusive_lock_guard< MutexT > > : mpl::integral_c< lock_access_mode, exclusive_access >
+{
+};
+
+template< typename MutexT >
+struct thread_access_mode_of< boost::log::aux::shared_lock_guard< MutexT > > : mpl::integral_c< lock_access_mode, shared_access >
+{
+};
+
+#endif // !defined(BOOST_LOG_NO_THREADS)
+
+namespace aux {
+
+//! The metafunction selects the most strict lock type of the two
+template<
+    typename LeftLockT,
+    typename RightLockT,
+#if !defined(BOOST_LOG_BROKEN_CONSTANT_EXPRESSIONS)
+    bool CondV = (thread_access_mode_of< LeftLockT >::value < thread_access_mode_of< RightLockT >::value)
+#else
+    bool CondV = mpl::less< thread_access_mode_of< LeftLockT >, thread_access_mode_of< RightLockT > >::value
+#endif
+>
+struct strictest_lock_impl
+{
+    typedef RightLockT type;
+};
+template< typename LeftLockT, typename RightLockT >
+struct strictest_lock_impl< LeftLockT, RightLockT, false >
+{
+    typedef LeftLockT type;
+};
+
+} // namespace aux
+
+#if defined(BOOST_LOG_DOXYGEN_PASS)
+
+/*!
+ * \brief The metafunction selects the most strict lock type of the specified.
+ *
+ * The template supports all lock types provided by the Boost.Thread
+ * library (except for \c upgrade_to_unique_lock), plus additional
+ * pseudo-lock \c no_lock that indicates no locking at all.
+ * Exclusive locks are considered the strictest, shared locks are weaker,
+ * and \c no_lock is the weakest.
+ */
+template< typename... LocksT >
+struct strictest_lock
+{
+    typedef implementation_defined type;
+};
+
+#else // defined(BOOST_LOG_DOXYGEN_PASS)
+
+#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+
+template< typename LockT, typename... LocksT >
+struct strictest_lock;
+
+template< typename LockT >
+struct strictest_lock< LockT >
+{
+    typedef LockT type;
+};
+
+template< typename LeftLockT, typename RightLockT >
+struct strictest_lock< LeftLockT, RightLockT >
+{
+    typedef typename aux::strictest_lock_impl< LeftLockT, RightLockT >::type type;
+};
+
+template< typename LeftLockT, typename RightLockT, typename... LocksT >
+struct strictest_lock< LeftLockT, RightLockT, LocksT... >
+{
+    typedef typename strictest_lock<
+        typename aux::strictest_lock_impl< LeftLockT, RightLockT >::type,
+        LocksT...
+    >::type type;
+};
+
+#else // !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+
+#   define BOOST_LOG_TYPE_INTERNAL(z, i, data) BOOST_PP_CAT(T, BOOST_PP_INC(i))
+
+template<
+    typename T,
+    BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(BOOST_PP_DEC(BOOST_LOG_STRICTEST_LOCK_LIMIT), typename T, void)
+>
+struct strictest_lock
+{
+    typedef typename strictest_lock<
+        typename boost::log::aux::strictest_lock_impl< T, T0 >::type
+        BOOST_PP_ENUM_TRAILING(BOOST_PP_SUB(BOOST_LOG_STRICTEST_LOCK_LIMIT, 2), BOOST_LOG_TYPE_INTERNAL, ~)
+    >::type type;
+};
+
+template< typename T >
+struct strictest_lock<
+    T
+    BOOST_PP_ENUM_TRAILING(BOOST_PP_DEC(BOOST_LOG_STRICTEST_LOCK_LIMIT), BOOST_LOG_PP_IDENTITY, void)
+>
+{
+    typedef T type;
+};
+
+#   undef BOOST_LOG_TYPE_INTERNAL
+
+#endif // !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+
+#endif // defined(BOOST_LOG_DOXYGEN_PASS)
+
+BOOST_LOG_CLOSE_NAMESPACE // namespace log
+
+} // namespace boost
+
+#include <boost/log/detail/footer.hpp>
+
+#endif // BOOST_LOG_UTILITY_STRICTEST_LOCK_HPP_INCLUDED_