+// A type transform to remove constness from the first part of a pair.
+// Pairs like that are used as the value_type of associative containers,
+// and this transform produces a similar but assignable pair.
+template <typename T>
+struct RemoveConstFromKey {
+ typedef T type;
+};
+
+// Partially specialized to remove constness from std::pair<const K, V>.
+template <typename K, typename V>
+struct RemoveConstFromKey<std::pair<const K, V> > {
+ typedef std::pair<K, V> type;
+};
+