整理

include/boost/pfr/detail/for_each_field.hpp

@@ -0,0 +1,65 @@
+// Copyright (c) 2016-2025 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_FOR_EACH_FIELD_HPP
+#define BOOST_PFR_DETAIL_FOR_EACH_FIELD_HPP
+#pragma once
+
+#include <boost/pfr/detail/config.hpp>
+
+#include <boost/pfr/detail/core.hpp>
+#include <boost/pfr/detail/fields_count.hpp>
+#include <boost/pfr/detail/for_each_field_impl.hpp>
+#include <boost/pfr/detail/make_integer_sequence.hpp>
+
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <type_traits>      // metaprogramming stuff
+#include <utility>          // forward_like
+#endif
+
+namespace boost { namespace pfr { namespace detail {
+
+template <class T, class F>
+constexpr void for_each_field(T&& value, F&& func) {
+#if BOOST_PFR_USE_CPP26
+    using no_ref = std::remove_reference_t<T>;
+    if constexpr (std::is_aggregate_v<no_ref> || std::is_bounded_array_v<no_ref>) {
+        auto &&[... members] = value;
+        ::boost::pfr::detail::for_each_field_impl(value,
+                                                  std::forward<F>(func),
+                                                  std::make_index_sequence<sizeof...(members)>{},
+                                                  std::is_rvalue_reference<T &&>{});
+    } else {
+        ::boost::pfr::detail::for_each_field_impl(value,
+                                                  std::forward<F>(func),
+                                                  std::make_index_sequence<1>{},
+                                                  std::is_rvalue_reference<T &&>{});
+    }
+#else
+    constexpr std::size_t fields_count_val = boost::pfr::detail::fields_count<std::remove_reference_t<T>>();
+
+    ::boost::pfr::detail::for_each_field_dispatcher(
+        value,
+        [f = std::forward<F>(func)](auto&& t) mutable {
+            // MSVC related workaround. Its lambdas do not capture constexprs.
+            constexpr std::size_t fields_count_val_in_lambda
+                = boost::pfr::detail::fields_count<std::remove_reference_t<T>>();
+
+            ::boost::pfr::detail::for_each_field_impl(
+                t,
+                std::forward<F>(f),
+                detail::make_index_sequence<fields_count_val_in_lambda>{},
+                std::is_rvalue_reference<T&&>{}
+            );
+        },
+        detail::make_index_sequence<fields_count_val>{}
+    );
+#endif
+}
+
+}}} // namespace boost::pfr::detail
+
+
+#endif // BOOST_PFR_DETAIL_FOR_EACH_FIELD_HPP