[Boost-commit] svn:boost r43774 - sandbox/SOC/2006/coroutine/branches/cleanup/boost/coroutine

From: gpderetta_at_[hidden]
Date: 2008-03-21 16:35:42

Author: giovanni.deretta
Date: 2008-03-21 16:35:41 EDT (Fri, 21 Mar 2008)
New Revision: 43774
URL: http://svn.boost.org/trac/boost/changeset/43774

Log:
removed another useless metaprogramming header
Removed:
   sandbox/SOC/2006/coroutine/branches/cleanup/boost/coroutine/tuple_traits.hpp

Deleted: sandbox/SOC/2006/coroutine/branches/cleanup/boost/coroutine/tuple_traits.hpp
==============================================================================
--- sandbox/SOC/2006/coroutine/branches/cleanup/boost/coroutine/tuple_traits.hpp	2008-03-21 16:35:41 EDT (Fri, 21 Mar 2008)
+++ (empty file)
@@ -1,170 +0,0 @@
-//  Copyright (c) 2006, Giovanni P. Deretta
-//
-//  This code may be used under either of the following two licences:
-//
-//  Permission is hereby granted, free of charge, to any person obtaining a copy 
-//  of this software and associated documentation files (the "Software"), to deal 
-//  in the Software without restriction, including without limitation the rights 
-//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
-//  copies of the Software, and to permit persons to whom the Software is 
-//  furnished to do so, subject to the following conditions:
-//
-//  The above copyright notice and this permission notice shall be included in 
-//  all copies or substantial portions of the Software.
-//
-//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
-//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
-//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
-//  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
-//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
-//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
-//  THE SOFTWARE. OF SUCH DAMAGE.
-//
-//  Or:
-//
-//  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)
-
-#ifndef BOOST_COROUTINE_TUPLE_TRAITS_HPP_20060613
-#define BOOST_COROUTINE_TUPLE_TRAITS_HPP_20060613
-#include <boost/tuple/tuple.hpp>
-#include <boost/preprocessor/repetition/enum_binary_params.hpp>
-#include <boost/preprocessor/facilities/intercept.hpp>
-#include <boost/type_traits.hpp>
-#include <boost/mpl/eval_if.hpp>
-#include <boost/mpl/if.hpp>
-#include <boost/mpl/identity.hpp>
-#include <boost/mpl/bool.hpp>
-#include <boost/coroutine/detail/arg_max.hpp>
-
-namespace boost { namespace coroutines {
-  namespace detail {
-    /*
-     * NOTE & FIXME: coroutine_traits relies on the fact that we can construct a
-     * boost::tuple specifing more arguments of type null_type than
-     * required without generating an error. This is an undocumented
-     * 'feature' and doesn't actually  work for nullary tuples,
-     * so we need to detect this case and handle it with tuple_workaround.
-     * If ever boost::tuple is changed (for example by switching to fusion)
-     * tuple_workaround should be used in all cases to handle extra 
-     * parameters.
-     * The real solution would be to have an internal tuple
-     * type that derives from boost::tuple and handles all cases we care about.
-     * Or better, just use Boost.Fusion.
-     * In general the code in this file needs to be put in a better shape,
-     * eliminating all corner cases.
-     */
-
-    /* 
-     * A boost::tuple<> is not constructible from an arbitrary
-     * number of null_types (while non nullary tuples are).
-     * This class takes care of this assimmetry.
-     */
-    struct tuple_workaround : boost::tuple<> {
-#     define BOOST_COROUTINE_arg_null_typecr(z, n, unused)\
-	const boost::tuples::null_type&                   \
-      /**/
-	
-      tuple_workaround
-      (BOOST_PP_ENUM
-       (BOOST_COROUTINE_ARG_MAX, 
-	BOOST_COROUTINE_arg_null_typecr,
-	~)){}
-	
-      tuple_workaround(const tuple_workaround&) {}
-      tuple_workaround() {}
-#     undef BOOST_COROUTINE_arg_null_typecr
-    };
-  } /* detail */
-
-  // All tuple traits must be derived from this
-  // class to be correctly recognized.
-  struct tuple_traits_tag {};
-      
-  template<typename T>
-  struct get_length {
-   enum { length = T::length };
-  };
-
-  template<typename T>
-  struct is_nullary :  boost::mpl::bool_<boost::tuples::length<T>::value == 0> {  };
-
-  template<typename T>
-  struct is_singular : boost::mpl::bool_<boost::tuples::length<T>::value == 1> {  };
-
-  // Given a tuple_traits, makes a tuple of it
-  // Simply returns the internal tuple type, unless
-  // the tuple is nullary, then apply the nullary tuple workaround
-  template<typename T>
-  struct make_as_tuple :
-    boost::mpl::if_<
-    is_nullary<T>,
-      detail::tuple_workaround,
-      T
-    > {};
-
-  // Used to implement the next metafunction,
-  // Splitted in two parts to satisfy the compiler.
-  template<typename T>
-  struct step_2 :
-      boost::mpl::eval_if<
-      is_singular<T>,
-      boost::tuples::element<0, typename make_as_tuple<T>::type >,
-    boost::mpl::identity<typename make_as_tuple<T>::type> > { };
-
-  // Given a trait class return the internal tuple type modified 
-  // as a return value.
-  // The algorithm is as follow:
-  // - If the tuple is nullary returns 'void'. 
-  // - If it singular returns the first type
-  // - Else return the tuple itself.
-  template<typename T>
-  struct make_result_type :
-    boost::mpl::eval_if<
-    is_nullary<T>,
-    boost::mpl::identity<void>,
-    step_2<T> > { };
-
-  template<
-    BOOST_PP_ENUM_BINARY_PARAMS
-  (BOOST_COROUTINE_ARG_MAX,
-   typename T, 
-   = boost::tuples::null_type BOOST_PP_INTERCEPT)>
-  struct tuple_traits : tuple_traits_tag {
-  public:	
-
-    // This is the straightforward boost::tuple trait
-    // derived from the argument list. It is not 
-    // directly used in all cases.
-    typedef boost::tuple
-    <BOOST_PP_ENUM_PARAMS
-    (BOOST_COROUTINE_ARG_MAX, T)> internal_tuple_type;
-
-    // FIXME: Currently coroutine code does not use this typedef in all cases
-    // and expect it to be equal to boost::tuples::null_type
-    typedef boost::tuples::null_type null_type;
-    enum {length = boost::tuples::length<internal_tuple_type>::value};
-
-    // Return the element at the Indext'th position in the typelist.
-    // If the index is not less than the tuple length, it returns 
-    // null_type.
-    template<int Index> 
-    struct at : 
-      boost::mpl::eval_if_c<
-      Index < 
-      boost::tuples::length<typename tuple_traits::internal_tuple_type>::value,
-      boost::tuples::element<Index, typename tuple_traits::internal_tuple_type>,	
-      boost::mpl::identity<typename tuple_traits::null_type> >{};
-
-    typedef typename make_as_tuple<internal_tuple_type>::type
-    as_tuple;	
-
-    typedef typename make_result_type<internal_tuple_type>::type as_result;
-
-  };
-    
-  template<typename T>
-  struct is_tuple_traits : boost::is_base_of<tuple_traits_tag, T> {};
-} }
-#endif