// Copyright (c) 2016-2020 Antony Polukhin
|
//
|
// 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_PFR_DETAIL_CORE17_HPP
|
#define BOOST_PFR_DETAIL_CORE17_HPP
|
|
#include <boost/pfr/detail/core17_generated.hpp>
|
#include <boost/pfr/detail/fields_count.hpp>
|
#include <boost/pfr/detail/for_each_field_impl.hpp>
|
#include <boost/pfr/detail/rvalue_t.hpp>
|
|
namespace boost { namespace pfr { namespace detail {
|
|
#ifndef _MSC_VER // MSVC fails to compile the following code, but compiles the structured bindings in core17_generated.hpp
|
struct do_not_define_std_tuple_size_for_me {
|
bool test1 = true;
|
};
|
|
template <class T>
|
constexpr bool do_structured_bindings_work() noexcept { // ******************************************* IN CASE OF ERROR READ THE FOLLOWING LINES IN boost/pfr/detail/core17.hpp FILE:
|
T val{};
|
const auto& [a] = val; // ******************************************* IN CASE OF ERROR READ THE FOLLOWING LINES IN boost/pfr/detail/core17.hpp FILE:
|
|
/****************************************************************************
|
*
|
* It looks like your compiler or Standard Library can not handle C++17
|
* structured bindings.
|
*
|
* Workaround: Define BOOST_PFR_USE_CPP17 to 0
|
* It will disable the C++17 features for Boost.PFR library.
|
*
|
* Sorry for the inconvenience caused.
|
*
|
****************************************************************************/
|
|
return a;
|
}
|
|
static_assert(
|
do_structured_bindings_work<do_not_define_std_tuple_size_for_me>(),
|
"====================> Boost.PFR: Your compiler can not handle C++17 structured bindings. Read the above comments for workarounds."
|
);
|
#endif // #ifndef _MSC_VER
|
|
template <class T>
|
constexpr auto tie_as_tuple(T& val) noexcept {
|
static_assert(
|
!std::is_union<T>::value,
|
"====================> Boost.PFR: For safety reasons it is forbidden to reflect unions. See `Reflection of unions` section in the docs for more info."
|
);
|
typedef size_t_<boost::pfr::detail::fields_count<T>()> fields_count_tag;
|
return boost::pfr::detail::tie_as_tuple(val, fields_count_tag{});
|
}
|
|
template <class T, class F, std::size_t... I>
|
void for_each_field_dispatcher(T& t, F&& f, std::index_sequence<I...>) {
|
static_assert(
|
!std::is_union<T>::value,
|
"====================> Boost.PFR: For safety reasons it is forbidden to reflect unions. See `Reflection of unions` section in the docs for more info."
|
);
|
std::forward<F>(f)(
|
detail::tie_as_tuple(t)
|
);
|
}
|
|
}}} // namespace boost::pfr::detail
|
|
#endif // BOOST_PFR_DETAIL_CORE17_HPP
|
