any/meta_any: safe but unspecified state after self move - close #1206

Related Work Items: #1

src/entt/core/any.hpp

@@ -249,12 +249,14 @@ public:
 
     /**
      * @brief Move assignment operator.
+     *
+     * @warning
+     * Self-moving puts objects in a safe but unspecified state.
+     *
      * @param other The instance to move from.
      * @return This any object.
      */
     basic_any &operator=(basic_any &&other) noexcept {
-        ENTT_ASSERT(this != &other, "Self move assignment");
-
         reset();
 
         if(other.mode == any_policy::embedded) {

src/entt/meta/meta.hpp

@@ -357,13 +357,15 @@ public:
 
     /**
      * @brief Move assignment operator.
+     *
+     * @warning
+     * Self-moving puts objects in a safe but unspecified state.
+     *
      * @param other The instance to move from.
      * @return This meta any object.
      */
     meta_any &operator=(meta_any &&other) noexcept {
-        ENTT_ASSERT(this != &other, "Self move assignment");
-
-        release();
+        reset();
         storage = std::move(other.storage);
         ctx = other.ctx;
         node = std::exchange(other.node, internal::meta_type_node{});