boost/intrusive/pack_options.hpp
/////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2013-2013
//
// 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)
//
// See http://www.boost.org/libs/intrusive for documentation.
//
/////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_INTRUSIVE_PACK_OPTIONS_HPP
#define BOOST_INTRUSIVE_PACK_OPTIONS_HPP
#include <boost/intrusive/detail/config_begin.hpp>
#if defined(BOOST_HAS_PRAGMA_ONCE)
# pragma once
#endif
namespace boost {
namespace intrusive {
#ifndef BOOST_INTRUSIVE_DOXYGEN_INVOKED
#if !defined(BOOST_INTRUSIVE_VARIADIC_TEMPLATES)
template<class Prev, class Next>
struct do_pack
{
//Use "pack" member template to pack options
typedef typename Next::template pack<Prev> type;
};
template<class Prev>
struct do_pack<Prev, void>
{
//Avoid packing "void" to shorten template names
typedef Prev type;
};
template
< class DefaultOptions
, class O1 = void
, class O2 = void
, class O3 = void
, class O4 = void
, class O5 = void
, class O6 = void
, class O7 = void
, class O8 = void
, class O9 = void
, class O10 = void
, class O11 = void
>
struct pack_options
{
// join options
typedef
typename do_pack
< typename do_pack
< typename do_pack
< typename do_pack
< typename do_pack
< typename do_pack
< typename do_pack
< typename do_pack
< typename do_pack
< typename do_pack
< typename do_pack
< DefaultOptions
, O1
>::type
, O2
>::type
, O3
>::type
, O4
>::type
, O5
>::type
, O6
>::type
, O7
>::type
, O8
>::type
, O9
>::type
, O10
>::type
, O11
>::type
type;
};
#else
//index_tuple
template<int... Indexes>
struct index_tuple{};
//build_number_seq
template<std::size_t Num, typename Tuple = index_tuple<> >
struct build_number_seq;
template<std::size_t Num, int... Indexes>
struct build_number_seq<Num, index_tuple<Indexes...> >
: build_number_seq<Num - 1, index_tuple<Indexes..., sizeof...(Indexes)> >
{};
template<int... Indexes>
struct build_number_seq<0, index_tuple<Indexes...> >
{ typedef index_tuple<Indexes...> type; };
template<class ...Types>
struct typelist
{};
//invert_typelist
template<class T>
struct invert_typelist;
template<int I, typename Tuple>
struct typelist_element;
template<int I, typename Head, typename... Tail>
struct typelist_element<I, typelist<Head, Tail...> >
{
typedef typename typelist_element<I-1, typelist<Tail...> >::type type;
};
template<typename Head, typename... Tail>
struct typelist_element<0, typelist<Head, Tail...> >
{
typedef Head type;
};
template<int ...Ints, class ...Types>
typelist<typename typelist_element<(sizeof...(Types) - 1) - Ints, typelist<Types...> >::type...>
inverted_typelist(index_tuple<Ints...>, typelist<Types...>)
{
return typelist<typename typelist_element<(sizeof...(Types) - 1) - Ints, typelist<Types...> >::type...>();
}
//sizeof_typelist
template<class Typelist>
struct sizeof_typelist;
template<class ...Types>
struct sizeof_typelist< typelist<Types...> >
{
static const std::size_t value = sizeof...(Types);
};
//invert_typelist_impl
template<class Typelist, class Indexes>
struct invert_typelist_impl;
template<class Typelist, int ...Ints>
struct invert_typelist_impl< Typelist, index_tuple<Ints...> >
{
static const std::size_t last_idx = sizeof_typelist<Typelist>::value - 1;
typedef typelist
<typename typelist_element<last_idx - Ints, Typelist>::type...> type;
};
template<class Typelist, int Int>
struct invert_typelist_impl< Typelist, index_tuple<Int> >
{
typedef Typelist type;
};
template<class Typelist>
struct invert_typelist_impl< Typelist, index_tuple<> >
{
typedef Typelist type;
};
//invert_typelist
template<class Typelist>
struct invert_typelist;
template<class ...Types>
struct invert_typelist< typelist<Types...> >
{
typedef typelist<Types...> typelist_t;
typedef typename build_number_seq<sizeof...(Types)>::type indexes_t;
typedef typename invert_typelist_impl<typelist_t, indexes_t>::type type;
};
//Do pack
template<class Typelist>
struct do_pack;
template<>
struct do_pack<typelist<> >;
template<class Prev>
struct do_pack<typelist<Prev> >
{
typedef Prev type;
};
template<class Prev, class Last>
struct do_pack<typelist<Prev, Last> >
{
typedef typename Prev::template pack<Last> type;
};
template<class ...Others>
struct do_pack<typelist<void, Others...> >
{
typedef typename do_pack<typelist<Others...> >::type type;
};
template<class Prev, class ...Others>
struct do_pack<typelist<Prev, Others...> >
{
typedef typename Prev::template pack
<typename do_pack<typelist<Others...> >::type> type;
};
template<class DefaultOptions, class ...Options>
struct pack_options
{
typedef typelist<DefaultOptions, Options...> typelist_t;
typedef typename invert_typelist<typelist_t>::type inverted_typelist;
typedef typename do_pack<inverted_typelist>::type type;
};
#endif //!defined(BOOST_INTRUSIVE_VARIADIC_TEMPLATES)
#define BOOST_INTRUSIVE_OPTION_TYPE(OPTION_NAME, TYPE, TYPEDEF_EXPR, TYPEDEF_NAME) \
template< class TYPE> \
struct OPTION_NAME \
{ \
template<class Base> \
struct pack : Base \
{ \
typedef TYPEDEF_EXPR TYPEDEF_NAME; \
}; \
}; \
//
#define BOOST_INTRUSIVE_OPTION_CONSTANT(OPTION_NAME, TYPE, VALUE, CONSTANT_NAME) \
template< TYPE VALUE> \
struct OPTION_NAME \
{ \
template<class Base> \
struct pack : Base \
{ \
static const TYPE CONSTANT_NAME = VALUE; \
}; \
}; \
//
#else //#ifndef BOOST_INTRUSIVE_DOXYGEN_INVOKED
//! This class is a utility that takes:
//! - a default options class defining initial static constant
//! and typedefs
//! - several options defined with BOOST_INTRUSIVE_OPTION_CONSTANT and
//! BOOST_INTRUSIVE_OPTION_TYPE
//!
//! and packs them together in a new type that defines all options as
//! member typedefs or static constant values. Given options of form:
//!
//! \code
//! BOOST_INTRUSIVE_OPTION_TYPE(my_pointer, VoidPointer, VoidPointer, my_pointer_type)
//! BOOST_INTRUSIVE_OPTION_CONSTANT(incremental, bool, Enabled, is_incremental)
//! \endcode
//!
//! the following expression
//!
//! \code
//!
//! struct default_options
//! {
//! typedef long int_type;
//! static const int int_constant = -1;
//! };
//!
//! pack_options< default_options, my_pointer<void*>, incremental<true> >::type
//! \endcode
//!
//! will create a type that will contain the following typedefs/constants
//!
//! \code
//! struct unspecified_type
//! {
//! //Default options
//! typedef long int_type;
//! static const int int_constant = -1;
//!
//! //Packed options (will ovewrite any default option)
//! typedef void* my_pointer_type;
//! static const bool is_incremental = true;
//! };
//! \endcode
//!
//! If an option is specified in the default options argument and later
//! redefined as an option, the last definition will prevail.
template<class DefaultOptions, class ...Options>
struct pack_options
{
typedef unspecified_type type;
};
//! Defines an option class of name OPTION_NAME that can be used to specify a type
//! of type TYPE...
//!
//! \code
//! struct OPTION_NAME<class TYPE>
//! { unspecified_content };
//! \endcode
//!
//! ...that after being combined with
//! <code>boost::intrusive::pack_options</code>,
//! will typedef TYPE as a typedef of name TYPEDEF_NAME. Example:
//!
//! \code
//! //[includes and namespaces omitted for brevity]
//!
//! //This macro will create the following class:
//! // template<class VoidPointer>
//! // struct my_pointer
//! // { unspecified_content };
//! BOOST_INTRUSIVE_OPTION_TYPE(my_pointer, VoidPointer, boost::remove_pointer<VoidPointer>::type, my_pointer_type)
//!
//! struct empty_default{};
//!
//! typedef pack_options< empty_default, typename my_pointer<void*> >::type::my_pointer_type type;
//!
//! BOOST_STATIC_ASSERT(( boost::is_same<type, void>::value ));
//!
//! \endcode
#define BOOST_INTRUSIVE_OPTION_TYPE(OPTION_NAME, TYPE, TYPEDEF_EXPR, TYPEDEF_NAME)
//! Defines an option class of name OPTION_NAME that can be used to specify a constant
//! of type TYPE with value VALUE...
//!
//! \code
//! struct OPTION_NAME<TYPE VALUE>
//! { unspecified_content };
//! \endcode
//!
//! ...that after being combined with
//! <code>boost::intrusive::pack_options</code>,
//! will contain a CONSTANT_NAME static constant of value VALUE. Example:
//!
//! \code
//! //[includes and namespaces omitted for brevity]
//!
//! //This macro will create the following class:
//! // template<bool Enabled>
//! // struct incremental
//! // { unspecified_content };
//! BOOST_INTRUSIVE_OPTION_CONSTANT(incremental, bool, Enabled, is_incremental)
//!
//! struct empty_default{};
//!
//! const bool is_incremental = pack_options< empty_default, incremental<true> >::type::is_incremental;
//!
//! BOOST_STATIC_ASSERT(( is_incremental == true ));
//!
//! \endcode
#define BOOST_INTRUSIVE_OPTION_CONSTANT(OPTION_NAME, TYPE, VALUE, CONSTANT_NAME)
#endif //#ifndef BOOST_INTRUSIVE_DOXYGEN_INVOKED
} //namespace intrusive {
} //namespace boost {
#include <boost/intrusive/detail/config_end.hpp>
#endif //#ifndef BOOST_INTRUSIVE_PACK_OPTIONS_HPP