Bugfix: move construct an empty fast_io::list

- before this patch, the list_move.cc#L10 will crash

Author: SekaiArendelle

include/fast_io_dsal/impl/list.h

@@ -907,15 +907,19 @@ class list
 	}
 
 	inline constexpr list(list &&other) noexcept
-		: imp(other.imp)
 		  #if 0
-		  , allochdl(std::move(other.allochdl))
+		  : allochdl(std::move(other.allochdl))
 		  #endif
 	{
-		auto prev = static_cast<::fast_io::containers::details::list_node_common *>(imp.prev);
-		auto next = static_cast<::fast_io::containers::details::list_node_common *>(imp.next);
-		next->prev = prev->next = __builtin_addressof(imp);
-		other.imp = {__builtin_addressof(other.imp), __builtin_addressof(other.imp)};
+		if (other.empty()) {
+			imp = {__builtin_addressof(imp), __builtin_addressof(imp)};
+		} else {
+			imp = other.imp;
+			auto prev = static_cast<::fast_io::containers::details::list_node_common *>(imp.prev);
+			auto next = static_cast<::fast_io::containers::details::list_node_common *>(imp.next);
+			next->prev = prev->next = __builtin_addressof(imp);
+			other.imp = {__builtin_addressof(other.imp), __builtin_addressof(other.imp)};
+		}
 	}
 
 	inline constexpr list &operator=(list &&other) noexcept

tests/0026.container/0002.list/list_move.cc

@@ -0,0 +1,27 @@
+
+#include <fast_io_dsal/list.h>
+
+int main() {
+    ::fast_io::list<int> l1{};
+    if (!l1.empty()) {
+        ::fast_io::fast_terminate();
+    }
+
+    ::fast_io::list<int> l2(::std::move(l1));
+    if (!l2.empty()) {
+        ::fast_io::fast_terminate();
+    }
+
+    ::fast_io::list<int> l3{};
+    l3.emplace_back(1);
+    if (l3.empty()) {
+        ::fast_io::fast_terminate();
+    }
+
+    ::fast_io::list<int> l4(::std::move(l3));
+    if (l4.empty()) {
+        ::fast_io::fast_terminate();
+    }
+
+    return 0;
+}