<%#
This is an ERB [1] template file used to generate the
<boost/hana/detail/struct_macros.hpp> header. The maximum
number of members that can be handled by the macros can
be controlled with the 'MAX_NUMBER_OF_MEMBERS' variable,
which can be set when calling ERB to generate the header:
export MAX_NUMBER_OF_MEMBERS=55; erb struct_macros.hpp.erb
'MAX_NUMBER_OF_MEMBERS' must be greater than 0. In case 'MAX_NUMBER_OF_MEMBERS'
is not specified, it defaults to 55. To regenerate the default struct macros,
issue the following command from the root of the project:
erb include/boost/hana/detail/struct_macros.hpp.erb > include/boost/hana/detail/struct_macros.hpp
[1]: http://en.wikipedia.org/wiki/ERuby
%>
<%
MAX_NUMBER_OF_MEMBERS = (ENV["MAX_NUMBER_OF_MEMBERS"] || 55).to_i
raise "MAX_NUMBER_OF_MEMBERS must be > 0" if not MAX_NUMBER_OF_MEMBERS > 0
%>
/*!
@file
Defines the `BOOST_HANA_DEFINE_STRUCT`, `BOOST_HANA_ADAPT_STRUCT`, and
`BOOST_HANA_ADAPT_ADT` macros.
Copyright Louis Dionne 2013-2022
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
*/
//////////////////////////////////////////////////////////////////////////////
// THIS FILE IS GENERATED FROM THE <boost/hana/detail/struct_macros.erb.hpp>
// ERB TEMPLATE. DO NOT EDIT THIS FILE DIRECTLY.
//
// THE ERB TEMPLATE CONTAINS INFORMATION ABOUT HOW TO REGENERATE THIS FILE.
//////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_HANA_DETAIL_STRUCT_MACROS_HPP
#define BOOST_HANA_DETAIL_STRUCT_MACROS_HPP
#include <boost/hana/config.hpp>
#include <boost/hana/detail/preprocessor.hpp>
#include <boost/hana/pair.hpp>
#include <boost/hana/string.hpp>
#include <boost/hana/tuple.hpp>
#include <cstddef>
#include <utility>
namespace boost { namespace hana { namespace struct_detail {
template <typename Memptr, Memptr ptr>
struct member_ptr {
template <typename T>
constexpr decltype(auto) operator()(T&& t) const
{ return static_cast<T&&>(t).*ptr; }
};
constexpr std::size_t strlen(char const* s) {
std::size_t n = 0;
while (*s++ != '\0')
++n;
return n;
}
template <std::size_t n, typename Names, std::size_t ...i>
constexpr auto prepare_member_name_impl(std::index_sequence<i...>) {
return hana::string_c<hana::at_c<n>(Names::get())[i]...>;
}
template <std::size_t n, typename Names>
constexpr auto prepare_member_name() {
constexpr std::size_t len = strlen(hana::at_c<n>(Names::get()));
return prepare_member_name_impl<n, Names>(std::make_index_sequence<len>{});
}
} }} // end namespace boost::hana
//////////////////////////////////////////////////////////////////////////////
// BOOST_HANA_PP_NARG
//////////////////////////////////////////////////////////////////////////////
//! @ingroup group-details
//! Macro expanding to the number of arguments it is passed.
//!
//! Specifically, `BOOST_HANA_PP_NARG(x1, ..., xn)` expands to `n`. It is
//! an error to call this macro with 0 arguments.
#ifdef BOOST_HANA_WORKAROUND_MSVC_PREPROCESSOR_616033
# define BOOST_HANA_PP_NARG(...) \
BOOST_HANA_PP_CONCAT(BOOST_HANA_PP_NARG_IMPL(__VA_ARGS__, <%= (1..MAX_NUMBER_OF_MEMBERS).to_a.reverse.join(',') %>,),)
#else
# define BOOST_HANA_PP_NARG(...) \
BOOST_HANA_PP_NARG_IMPL(__VA_ARGS__, <%= (1..MAX_NUMBER_OF_MEMBERS).to_a.reverse.join(',') %>,)
#endif
#define BOOST_HANA_PP_NARG_IMPL(<%= (1..MAX_NUMBER_OF_MEMBERS).to_a.map { |i| "e#{i}" }.join(',') %>, N, ...) N
//////////////////////////////////////////////////////////////////////////////
// BOOST_HANA_PP_BACK
//////////////////////////////////////////////////////////////////////////////
//! @ingroup group-details
//! Expands to its last argument.
#define BOOST_HANA_PP_BACK(...) \
BOOST_HANA_PP_BACK_IMPL(BOOST_HANA_PP_NARG(__VA_ARGS__), __VA_ARGS__)
#ifdef BOOST_HANA_WORKAROUND_MSVC_PREPROCESSOR_616033
# define BOOST_HANA_PP_BACK_IMPL(N, ...) BOOST_HANA_PP_BACK_IMPL_I(N, __VA_ARGS__)
# define BOOST_HANA_PP_BACK_IMPL_I(N, ...) \
BOOST_HANA_PP_CONCAT(BOOST_HANA_PP_CONCAT(BOOST_HANA_PP_BACK_IMPL_, N)(__VA_ARGS__),)
#else
# define BOOST_HANA_PP_BACK_IMPL(N, ...) \
BOOST_HANA_PP_CONCAT(BOOST_HANA_PP_BACK_IMPL_, N)(__VA_ARGS__)
#endif
<% (1..MAX_NUMBER_OF_MEMBERS).each do |n| %>
#define BOOST_HANA_PP_BACK_IMPL_<%= n %>(<%= (1..n).to_a.map { |i| "e#{i}" }.join(', ') %>) e<%= n %>
<% end %>
//////////////////////////////////////////////////////////////////////////////
// BOOST_HANA_PP_DROP_BACK
//////////////////////////////////////////////////////////////////////////////
//! @ingroup group-details
//! Expands to all of its arguments, except for the last one.
#define BOOST_HANA_PP_DROP_BACK(...) \
BOOST_HANA_PP_DROP_BACK_IMPL(BOOST_HANA_PP_NARG(__VA_ARGS__), __VA_ARGS__)
#ifdef BOOST_HANA_WORKAROUND_MSVC_PREPROCESSOR_616033
# define BOOST_HANA_PP_DROP_BACK_IMPL(N, ...) BOOST_HANA_PP_DROP_BACK_IMPL_I(N, __VA_ARGS__)
# define BOOST_HANA_PP_DROP_BACK_IMPL_I(N, ...) \
BOOST_HANA_PP_CONCAT(BOOST_HANA_PP_CONCAT(BOOST_HANA_PP_DROP_BACK_IMPL_, N)(__VA_ARGS__),)
#else
# define BOOST_HANA_PP_DROP_BACK_IMPL(N, ...) \
BOOST_HANA_PP_CONCAT(BOOST_HANA_PP_DROP_BACK_IMPL_, N)(__VA_ARGS__)
#endif
<% (1..MAX_NUMBER_OF_MEMBERS).each do |n| %>
#define BOOST_HANA_PP_DROP_BACK_IMPL_<%= n %>(<%= (1..n).to_a.map { |i| "e#{i}" }.join(', ') %>)<%= (1..n-1).to_a.map { |i| "e#{i}" }.join(', ') %>
<% end %>
//////////////////////////////////////////////////////////////////////////////
// BOOST_HANA_ADAPT_STRUCT
//////////////////////////////////////////////////////////////////////////////
template <typename ...>
struct BOOST_HANA_ADAPT_STRUCT_must_be_called_in_the_global_namespace;
#define BOOST_HANA_ADAPT_STRUCT(...) \
template <> \
struct BOOST_HANA_ADAPT_STRUCT_must_be_called_in_the_global_namespace<>; \
BOOST_HANA_ADAPT_STRUCT_IMPL(BOOST_HANA_PP_NARG(__VA_ARGS__), __VA_ARGS__)\
static_assert(true, "force the usage of a trailing semicolon") \
/**/
#ifdef BOOST_HANA_WORKAROUND_MSVC_PREPROCESSOR_616033
# define BOOST_HANA_ADAPT_STRUCT_IMPL(N, ...) BOOST_HANA_ADAPT_STRUCT_IMPL_I(N, __VA_ARGS__)
# define BOOST_HANA_ADAPT_STRUCT_IMPL_I(N, ...) \
BOOST_HANA_PP_CONCAT(BOOST_HANA_PP_CONCAT(BOOST_HANA_ADAPT_STRUCT_IMPL_, N)(__VA_ARGS__),)
#else
# define BOOST_HANA_ADAPT_STRUCT_IMPL(N, ...) \
BOOST_HANA_PP_CONCAT(BOOST_HANA_ADAPT_STRUCT_IMPL_, N)(__VA_ARGS__)
#endif
<% (0..MAX_NUMBER_OF_MEMBERS).each do |n| %>
#define BOOST_HANA_ADAPT_STRUCT_IMPL_<%= n+1 %>(TYPE <%= (1..n).map { |i| ", m#{i}" }.join %>) \
namespace boost { namespace hana { \
template <> \
struct accessors_impl<TYPE> { \
static constexpr auto apply() { \
struct member_names { \
static constexpr auto get() { \
return ::boost::hana::make_tuple( \
<%= (1..n).map { |i| "BOOST_HANA_PP_STRINGIZE(m#{i})" }.join(', ') %> \
); \
} \
}; \
return ::boost::hana::make_tuple( \
<%= (1..n).map { |i| "::boost::hana::make_pair(::boost::hana::struct_detail::prepare_member_name<#{i-1}, member_names>(), ::boost::hana::struct_detail::member_ptr<decltype(&TYPE::m#{i}), &TYPE::m#{i}>{})" }.join(', ') %>\
); \
} \
}; \
}} \
/**/
<% end %>
//////////////////////////////////////////////////////////////////////////////
// BOOST_HANA_ADAPT_ADT
//////////////////////////////////////////////////////////////////////////////
template <typename ...>
struct BOOST_HANA_ADAPT_ADT_must_be_called_in_the_global_namespace;
#define BOOST_HANA_ADAPT_ADT(...) \
template <> \
struct BOOST_HANA_ADAPT_ADT_must_be_called_in_the_global_namespace<>; \
BOOST_HANA_ADAPT_ADT_IMPL(BOOST_HANA_PP_NARG(__VA_ARGS__), __VA_ARGS__) \
static_assert(true, "force the usage of a trailing semicolon") \
/**/
#ifdef BOOST_HANA_WORKAROUND_MSVC_PREPROCESSOR_616033
# define BOOST_HANA_ADAPT_ADT_IMPL(N, ...) BOOST_HANA_ADAPT_ADT_IMPL_I(N, __VA_ARGS__)
# define BOOST_HANA_ADAPT_ADT_IMPL_I(N, ...) \
BOOST_HANA_PP_CONCAT(BOOST_HANA_PP_CONCAT(BOOST_HANA_ADAPT_ADT_IMPL_, N)(__VA_ARGS__),)
#else
# define BOOST_HANA_ADAPT_ADT_IMPL(N, ...) \
BOOST_HANA_PP_CONCAT(BOOST_HANA_ADAPT_ADT_IMPL_, N)(__VA_ARGS__)
#endif
<% (0..MAX_NUMBER_OF_MEMBERS).each do |n| %>
#define BOOST_HANA_ADAPT_ADT_IMPL_<%= n+1 %>(TYPE <%= (1..n).map { |i| ", m#{i}" }.join %>) \
namespace boost { namespace hana { \
template <> \
struct accessors_impl<TYPE> { \
template <typename ...> \
static constexpr auto apply() { \
struct member_names { \
static constexpr auto get() { \
return ::boost::hana::make_tuple( \
<%= (1..n).map { |i| "BOOST_HANA_PP_STRINGIZE(BOOST_HANA_PP_FRONT m#{i})" }.join(', ') %>\
); \
} \
}; \
return ::boost::hana::make_tuple( \
<%= (1..n).map { |i| "::boost::hana::make_pair(::boost::hana::struct_detail::prepare_member_name<#{i-1}, member_names>(), BOOST_HANA_PP_DROP_FRONT m#{i})" }.join(', ') %>\
); \
} \
}; \
}} \
/**/
<% end %>
//////////////////////////////////////////////////////////////////////////////
// BOOST_HANA_DEFINE_STRUCT
//////////////////////////////////////////////////////////////////////////////
#define BOOST_HANA_DEFINE_STRUCT(...) \
BOOST_HANA_DEFINE_STRUCT_IMPL(BOOST_HANA_PP_NARG(__VA_ARGS__), __VA_ARGS__)
#ifdef BOOST_HANA_WORKAROUND_MSVC_PREPROCESSOR_616033
# define BOOST_HANA_DEFINE_STRUCT_IMPL(N, ...) BOOST_HANA_DEFINE_STRUCT_IMPL_I(N, __VA_ARGS__)
# define BOOST_HANA_DEFINE_STRUCT_IMPL_I(N, ...) \
BOOST_HANA_PP_CONCAT(BOOST_HANA_PP_CONCAT(BOOST_HANA_DEFINE_STRUCT_IMPL_, N)(__VA_ARGS__),)
#else
# define BOOST_HANA_DEFINE_STRUCT_IMPL(N, ...) \
BOOST_HANA_PP_CONCAT(BOOST_HANA_DEFINE_STRUCT_IMPL_, N)(__VA_ARGS__)
#endif
<% (0..MAX_NUMBER_OF_MEMBERS).each do |n| %>
#define BOOST_HANA_DEFINE_STRUCT_IMPL_<%= n+1 %>(TYPE <%= (1..n).map { |i| ", m#{i}" }.join %>) \
<%= (1..n).map { |i| "BOOST_HANA_PP_DROP_BACK m#{i} BOOST_HANA_PP_BACK m#{i};" }.join(' ') %> \
\
struct hana_accessors_impl { \
static constexpr auto apply() { \
struct member_names { \
static constexpr auto get() { \
return ::boost::hana::make_tuple( \
<%= (1..n).map { |i| "BOOST_HANA_PP_STRINGIZE(BOOST_HANA_PP_BACK m#{i})" }.join(', ') %>\
); \
} \
}; \
return ::boost::hana::make_tuple( \
<%= (1..n).map { |i| "::boost::hana::make_pair(::boost::hana::struct_detail::prepare_member_name<#{i-1}, member_names>(), ::boost::hana::struct_detail::member_ptr<decltype(&TYPE::BOOST_HANA_PP_BACK m#{i}), &TYPE::BOOST_HANA_PP_BACK m#{i}>{})" }.join(', ') %>\
); \
} \
} \
/**/
<% end %>
#endif // !BOOST_HANA_DETAIL_STRUCT_MACROS_HPP