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author | Chanho Park <chanho61.park@samsung.com> | 2014-12-11 18:55:56 +0900 |
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committer | Chanho Park <chanho61.park@samsung.com> | 2014-12-11 18:55:56 +0900 |
commit | 08c1e93fa36a49f49325a07fe91ff92c964c2b6c (patch) | |
tree | 7a7053ceb8874b28ec4b868d4c49b500008a102e /boost/log/detail/singleton.hpp | |
parent | bb4dd8289b351fae6b55e303f189127a394a1edd (diff) | |
download | boost-08c1e93fa36a49f49325a07fe91ff92c964c2b6c.tar.gz boost-08c1e93fa36a49f49325a07fe91ff92c964c2b6c.tar.bz2 boost-08c1e93fa36a49f49325a07fe91ff92c964c2b6c.zip |
Imported Upstream version 1.57.0upstream/1.57.0
Diffstat (limited to 'boost/log/detail/singleton.hpp')
-rw-r--r-- | boost/log/detail/singleton.hpp | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/boost/log/detail/singleton.hpp b/boost/log/detail/singleton.hpp new file mode 100644 index 0000000000..ac1ac1afe0 --- /dev/null +++ b/boost/log/detail/singleton.hpp @@ -0,0 +1,89 @@ +/* + * 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 singleton.hpp + * \author Andrey Semashev + * \date 20.04.2008 + * + * \brief This header is the Boost.Log library implementation, see the library documentation + * at http://www.boost.org/doc/libs/release/libs/log/doc/html/index.html. + */ + +#ifndef BOOST_LOG_DETAIL_SINGLETON_HPP_INCLUDED_ +#define BOOST_LOG_DETAIL_SINGLETON_HPP_INCLUDED_ + +#include <boost/log/detail/config.hpp> +#include <boost/log/utility/once_block.hpp> +#include <boost/log/detail/header.hpp> + +#ifdef BOOST_HAS_PRAGMA_ONCE +#pragma once +#endif + +namespace boost { + +BOOST_LOG_OPEN_NAMESPACE + +namespace aux { + +//! A base class for singletons, constructed on-demand +template< typename DerivedT, typename StorageT = DerivedT > +class lazy_singleton +{ +public: + BOOST_DEFAULTED_FUNCTION(lazy_singleton(), {}) + + //! Returns the singleton instance + static StorageT& get() + { + BOOST_LOG_ONCE_BLOCK() + { + DerivedT::init_instance(); + } + return get_instance(); + } + + //! Initializes the singleton instance + static void init_instance() + { + get_instance(); + } + + BOOST_DELETED_FUNCTION(lazy_singleton(lazy_singleton const&)) + BOOST_DELETED_FUNCTION(lazy_singleton& operator= (lazy_singleton const&)) + +protected: + //! Returns the singleton instance (not thread-safe) + static StorageT& get_instance() + { + static StorageT instance; + return instance; + } +}; + +//! A base class for singletons, constructed on namespace scope initialization stage +template< typename DerivedT, typename StorageT = DerivedT > +class singleton : + public lazy_singleton< DerivedT, StorageT > +{ +public: + static StorageT& instance; +}; + +template< typename DerivedT, typename StorageT > +StorageT& singleton< DerivedT, StorageT >::instance = + lazy_singleton< DerivedT, StorageT >::get(); + +} // namespace aux + +BOOST_LOG_CLOSE_NAMESPACE // namespace log + +} // namespace boost + +#include <boost/log/detail/footer.hpp> + +#endif // BOOST_LOG_DETAIL_SINGLETON_HPP_INCLUDED_ |