Update code to be valid when the internal buckets_ data member is moved-from

include/boost/unordered/detail/implementation.hpp

@@ -2054,12 +2054,14 @@ namespace boost {
 
         std::size_t bucket_size(std::size_t index) const
         {
-          bucket_iterator itb = buckets_.at(index);
-          node_pointer n = itb->next;
           std::size_t count = 0;
-          while (n) {
-            ++count;
-            n = n->next;
+          if (size_ > 0) {
+            bucket_iterator itb = buckets_.at(index);
+            node_pointer n = itb->next;
+            while (n) {
+              ++count;
+              n = n->next;
+            }
           }
           return count;
         }
@@ -2420,11 +2422,14 @@ namespace boost {
         node_pointer find_node_impl(
           Key const& x, bucket_iterator itb) const
         {
-          key_equal const& pred = this->key_eq();
-          node_pointer p = itb->next;
-          for (; p; p = p->next) {
-            if (pred(x, extractor::extract(p->value()))) {
-              break;
+          node_pointer p = node_pointer();
+          if (itb != buckets_.end()) {
+            key_equal const& pred = this->key_eq();
+            p = itb->next;
+            for (; p; p = p->next) {
+              if (pred(x, extractor::extract(p->value()))) {
+                break;
+              }
             }
           }
           return p;
@@ -2453,11 +2458,13 @@ namespace boost {
         inline iterator transparent_find(
           Key const& k, Hash const& h, Pred const& pred) const
         {
-          std::size_t const key_hash = h(k);
-          bucket_iterator itb = buckets_.at(buckets_.position(key_hash));
-          for (node_pointer p = itb->next; p; p = p->next) {
-            if (BOOST_LIKELY(pred(k, extractor::extract(p->value())))) {
-              return iterator(p, itb);
+          if (size_ > 0) {
+            std::size_t const key_hash = h(k);
+            bucket_iterator itb = buckets_.at(buckets_.position(key_hash));
+            for (node_pointer p = itb->next; p; p = p->next) {
+              if (BOOST_LIKELY(pred(k, extractor::extract(p->value())))) {
+                return iterator(p, itb);
+              }
             }
           }
 
@@ -2467,11 +2474,13 @@ namespace boost {
         template <class Key>
         node_pointer* find_prev(Key const& key, bucket_iterator itb)
         {
-          key_equal pred = this->key_eq();
-          for (node_pointer* pp = boost::addressof(itb->next); *pp;
-               pp = boost::addressof((*pp)->next)) {
-            if (pred(key, extractor::extract((*pp)->value()))) {
-              return pp;
+          if (size_ > 0) {
+            key_equal pred = this->key_eq();
+            for (node_pointer* pp = boost::addressof(itb->next); *pp;
+                pp = boost::addressof((*pp)->next)) {
+              if (pred(key, extractor::extract((*pp)->value()))) {
+                return pp;
+              }
             }
           }
           typedef node_pointer* node_pointer_pointer;