comparison DEPENDENCIES/generic/include/boost/log/expressions/attr.hpp @ 16:2665513ce2d3

Add boost headers

+/*
+ *          Copyright Andrey Semashev 2007 - 2013.
+ * 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   attr.hpp
+ * \author Andrey Semashev
+ * \date   21.07.2012
+ *
+ * The header contains implementation of a generic attribute placeholder in template expressions.
+ */
+
+#ifndef BOOST_LOG_EXPRESSIONS_ATTR_HPP_INCLUDED_
+#define BOOST_LOG_EXPRESSIONS_ATTR_HPP_INCLUDED_
+
+#include <boost/mpl/bool.hpp>
+#include <boost/utility/result_of.hpp>
+#include <boost/phoenix/core/actor.hpp>
+#include <boost/phoenix/core/terminal_fwd.hpp>
+#include <boost/phoenix/core/is_nullary.hpp>
+#include <boost/phoenix/core/environment.hpp>
+#include <boost/fusion/sequence/intrinsic/at_c.hpp>
+#include <boost/type_traits/remove_cv.hpp>
+#include <boost/type_traits/remove_reference.hpp>
+#include <boost/log/detail/config.hpp>
+#include <boost/log/detail/custom_terminal_spec.hpp>
+#include <boost/log/attributes/attribute_name.hpp>
+#include <boost/log/attributes/value_extraction.hpp>
+#include <boost/log/attributes/fallback_policy.hpp>
+#include <boost/log/expressions/attr_fwd.hpp>
+#include <boost/log/detail/header.hpp>
+
+#ifdef BOOST_HAS_PRAGMA_ONCE
+#pragma once
+#endif
+
+namespace boost {
+
+BOOST_LOG_OPEN_NAMESPACE
+
+namespace expressions {
+
+/*!
+ * An attribute value extraction terminal
+ */
+template< typename T, typename FallbackPolicyT, typename TagT >
+class attribute_terminal
+{
+private:
+    //! Value extractor type
+    typedef value_extractor< T, FallbackPolicyT, TagT > value_extractor_type;
+    //! Self type
+    typedef attribute_terminal< T, FallbackPolicyT, TagT > this_type;
+
+public:
+    //! Internal typedef for type categorization
+    typedef void _is_boost_log_terminal;
+
+    //! Attribute tag type
+    typedef TagT tag_type;
+    //! Attribute value type
+    typedef typename value_extractor_type::value_type value_type;
+    //! Fallback policy type
+    typedef typename value_extractor_type::fallback_policy fallback_policy;
+
+    //! Function result type
+    template< typename >
+    struct result;
+
+    template< typename ContextT >
+    struct result< this_type(ContextT) >
+    {
+        typedef typename remove_cv<
+            typename remove_reference< typename phoenix::result_of::env< ContextT >::type >::type
+        >::type env_type;
+        typedef typename env_type::args_type args_type;
+
+        typedef typename boost::result_of< value_extractor_type(attribute_name const&, typename fusion::result_of::at_c< args_type, 0 >::type) >::type type;
+    };
+
+    template< typename ContextT >
+    struct result< const this_type(ContextT) >
+    {
+        typedef typename remove_cv<
+            typename remove_reference< typename phoenix::result_of::env< ContextT >::type >::type
+        >::type env_type;
+        typedef typename env_type::args_type args_type;
+
+        typedef typename boost::result_of< const value_extractor_type(attribute_name const&, typename fusion::result_of::at_c< args_type, 0 >::type) >::type type;
+    };
+
+private:
+    //! Attribute value name
+    const attribute_name m_name;
+    //! Attribute value extractor
+    value_extractor_type m_value_extractor;
+
+public:
+    /*!
+     * Initializing constructor
+     */
+    explicit attribute_terminal(attribute_name const& name) : m_name(name)
+    {
+    }
+
+    /*!
+     * Initializing constructor
+     */
+    template< typename U >
+    attribute_terminal(attribute_name const& name, U const& arg) : m_name(name), m_value_extractor(arg)
+    {
+    }
+
+    /*!
+     * \returns Attribute value name
+     */
+    attribute_name get_name() const
+    {
+        return m_name;
+    }
+
+    /*!
+     * \returns Fallback policy
+     */
+    fallback_policy const& get_fallback_policy() const
+    {
+        return m_value_extractor.get_fallback_policy();
+    }
+
+    /*!
+     * The operator extracts attribute value
+     */
+    template< typename ContextT >
+    typename result< this_type(ContextT const&) >::type
+    operator() (ContextT const& ctx)
+    {
+        return m_value_extractor(m_name, fusion::at_c< 0 >(phoenix::env(ctx).args()));
+    }
+
+    /*!
+     * The operator extracts attribute value
+     */
+    template< typename ContextT >
+    typename result< const this_type(ContextT const&) >::type
+    operator() (ContextT const& ctx) const
+    {
+        return m_value_extractor(m_name, fusion::at_c< 0 >(phoenix::env(ctx).args()));
+    }
+
+    BOOST_DELETED_FUNCTION(attribute_terminal())
+};
+
+/*!
+ * An attribute value extraction terminal actor
+ */
+template< typename T, typename FallbackPolicyT, typename TagT, template< typename > class ActorT >
+class attribute_actor :
+    public ActorT< attribute_terminal< T, FallbackPolicyT, TagT > >
+{
+public:
+    //! Attribute tag type
+    typedef TagT tag_type;
+    //! Fallback policy
+    typedef FallbackPolicyT fallback_policy;
+    //! Base terminal type
+    typedef attribute_terminal< T, fallback_policy, tag_type > terminal_type;
+    //! Attribute value type
+    typedef typename terminal_type::value_type value_type;
+
+    //! Base actor type
+    typedef ActorT< terminal_type > base_type;
+
+public:
+    //! Initializing constructor
+    explicit attribute_actor(base_type const& act) : base_type(act)
+    {
+    }
+
+    /*!
+     * \returns The attribute name
+     */
+    attribute_name get_name() const
+    {
+        return this->proto_expr_.child0.get_name();
+    }
+
+    /*!
+     * \returns Fallback policy
+     */
+    fallback_policy const& get_fallback_policy() const
+    {
+        return this->proto_expr_.child0.get_fallback_policy();
+    }
+
+    //! Expression with cached attribute name
+    typedef attribute_actor< value_type, fallback_to_none, tag_type, ActorT > or_none_result_type;
+
+    //! Generates an expression that extracts the attribute value or a default value
+    or_none_result_type or_none() const
+    {
+        typedef typename or_none_result_type::terminal_type result_terminal;
+        typename or_none_result_type::base_type act = {{ result_terminal(get_name()) }};
+        return or_none_result_type(act);
+    }
+
+    //! Expression with cached attribute name
+    typedef attribute_actor< value_type, fallback_to_throw, tag_type, ActorT > or_throw_result_type;
+
+    //! Generates an expression that extracts the attribute value or throws an exception
+    or_throw_result_type or_throw() const
+    {
+        typedef typename or_throw_result_type::terminal_type result_terminal;
+        typename or_throw_result_type::base_type act = {{ result_terminal(get_name()) }};
+        return or_throw_result_type(act);
+    }
+
+    //! Generates an expression that extracts the attribute value or a default value
+    template< typename DefaultT >
+    attribute_actor< value_type, fallback_to_default< DefaultT >, tag_type, ActorT > or_default(DefaultT const& def_val) const
+    {
+        typedef attribute_actor< value_type, fallback_to_default< DefaultT >, tag_type, ActorT > or_default_result_type;
+        typedef typename or_default_result_type::terminal_type result_terminal;
+        typename or_default_result_type::base_type act = {{ result_terminal(get_name(), def_val) }};
+        return or_default_result_type(act);
+    }
+};
+
+/*!
+ * The function generates a terminal node in a template expression. The node will extract the value of the attribute
+ * with the specified name and type.
+ */
+template< typename AttributeValueT >
+BOOST_FORCEINLINE attribute_actor< AttributeValueT > attr(attribute_name const& name)
+{
+    typedef attribute_actor< AttributeValueT > result_type;
+    typedef typename result_type::terminal_type result_terminal;
+    typename result_type::base_type act = {{ result_terminal(name) }};
+    return result_type(act);
+}
+
+/*!
+ * The function generates a terminal node in a template expression. The node will extract the value of the attribute
+ * with the specified name and type.
+ */
+template< typename AttributeValueT, typename TagT >
+BOOST_FORCEINLINE attribute_actor< AttributeValueT, fallback_to_none, TagT > attr(attribute_name const& name)
+{
+    typedef attribute_actor< AttributeValueT, fallback_to_none, TagT > result_type;
+    typedef typename result_type::terminal_type result_terminal;
+    typename result_type::base_type act = {{ result_terminal(name) }};
+    return result_type(act);
+}
+
+} // namespace expressions
+
+BOOST_LOG_CLOSE_NAMESPACE // namespace log
+
+#ifndef BOOST_LOG_DOXYGEN_PASS
+
+namespace phoenix {
+
+namespace result_of {
+
+template< typename T, typename FallbackPolicyT, typename TagT >
+struct is_nullary< custom_terminal< boost::log::expressions::attribute_terminal< T, FallbackPolicyT, TagT > > > :
+    public mpl::false_
+{
+};
+
+} // namespace result_of
+
+} // namespace phoenix
+
+#endif
+
+} // namespace boost
+
+#include <boost/log/detail/footer.hpp>
+#if defined(BOOST_LOG_EXPRESSIONS_FORMATTERS_STREAM_HPP_INCLUDED_)
+#include <boost/log/detail/attr_output_impl.hpp>
+#endif
+
+#endif // BOOST_LOG_EXPRESSIONS_ATTR_HPP_INCLUDED_