From fac9931eb6b34b5a66fedba45c4c984fb40d22ff Mon Sep 17 00:00:00 2001
From: arvidn <arvid@libtorrent.org>
Date: Thu, 4 Jan 2018 21:02:34 +0100
Subject: [PATCH] fix noexcept marking on entry, and make move assignment

---
 include/libtorrent/aux_/noexcept_movable.hpp |  4 ++-
 include/libtorrent/entry.hpp                 |  2 +-
 src/entry.cpp                                | 37 +++++++++++++++-----
 3 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/include/libtorrent/aux_/noexcept_movable.hpp b/include/libtorrent/aux_/noexcept_movable.hpp
index 28715ebde..283990c8d 100644
--- a/include/libtorrent/aux_/noexcept_movable.hpp
+++ b/include/libtorrent/aux_/noexcept_movable.hpp
@@ -32,6 +32,8 @@ POSSIBILITY OF SUCH DAMAGE.
 #ifndef TORRENT_NOEXCEPT_MOVABLE_HPP_INCLUDED
 #define TORRENT_NOEXCEPT_MOVABLE_HPP_INCLUDED
 
+#include <type_traits>
+
 namespace libtorrent {
 namespace aux {
 
@@ -42,7 +44,7 @@ namespace aux {
 	template <typename T>
 	struct noexcept_movable : T
 	{
-		noexcept_movable() noexcept {}
+		noexcept_movable() noexcept(std::is_nothrow_default_constructible<T>::value) {}
 		noexcept_movable(noexcept_movable<T>&& rhs) noexcept
 			: T(std::forward<T>(rhs))
 		{}
diff --git a/include/libtorrent/entry.hpp b/include/libtorrent/entry.hpp
index a0b45b424..1ead27943 100644
--- a/include/libtorrent/entry.hpp
+++ b/include/libtorrent/entry.hpp
@@ -274,7 +274,7 @@ namespace aux {
 		const preformatted_type& preformatted() const;
 
 		// swaps the content of *this* with ``e``.
-		void swap(entry& e) noexcept;
+		void swap(entry& e);
 
 		// All of these functions requires the entry to be a dictionary, if it
 		// isn't they will throw ``system_error``.
diff --git a/src/entry.cpp b/src/entry.cpp
index 878f578a5..7edea630f 100644
--- a/src/entry.cpp
+++ b/src/entry.cpp
@@ -143,7 +143,32 @@ namespace {
 	entry& entry::operator=(entry&& e) noexcept
 	{
 		if (&e == this) return *this;
-		swap(e);
+		destruct();
+		const auto t = e.type();
+		switch (t)
+		{
+		case int_t:
+			new (&data) integer_type(std::move(e.integer()));
+			break;
+		case string_t:
+			new (&data) string_type(std::move(e.string()));
+			break;
+		case list_t:
+			new (&data) list_type(std::move(e.list()));
+			break;
+		case dictionary_t:
+			new (&data) dictionary_type(std::move(e.dict()));
+			break;
+		case undefined_t:
+			break;
+		case preformatted_t:
+			new (&data) preformatted_type(std::move(e.preformatted()));
+			break;
+		}
+		m_type = t;
+#if TORRENT_USE_ASSERTS
+		m_type_queried = true;
+#endif
 		return *this;
 	}
 
@@ -281,13 +306,7 @@ namespace {
 	entry::entry(entry&& e) noexcept
 		: m_type(undefined_t)
 	{
-#if TORRENT_USE_ASSERTS
-		uint8_t type_queried = e.m_type_queried;
-#endif
-		swap(e);
-#if TORRENT_USE_ASSERTS
-		m_type_queried = type_queried;
-#endif
+		this->operator=(std::move(e));
 	}
 
 	entry::entry(dictionary_type v)
@@ -581,7 +600,7 @@ namespace {
 #endif
 	}
 
-	void entry::swap(entry& e) noexcept
+	void entry::swap(entry& e)
 	{
 		bool clear_this = false;
 		bool clear_that = false;