hashtable (identity<>::operator(), [...]): Return by const ref.

2006-05-13  Peter Doerfler  <gcc@pdoerfler.com>

	* include/tr1/hashtable (identity<>::operator(),
	extract1st<>::operator()): Return by const ref.

From-SVN: r113737

libstdc++-v3/ChangeLog

+2006-05-13  Peter Doerfler  <gcc@pdoerfler.com>
+
+	* include/tr1/hashtable (identity<>::operator(),
+	extract1st<>::operator()): Return by const ref.
+
 2006-05-10  Steve Ellcey  <sje@cup.hp.com>
 
 	* testsuite/lib/libstdc++.exp (check_v3_target_cxa_atexit):

libstdc++-v3/include/tr1/hashtable

@@ -404,7 +404,7 @@ namespace Internal
   template<typename T>
     struct identity
     {
-      T
+      const T&
       operator()(const T& t) const
       { return t; }
     };
@@ -412,7 +412,7 @@ namespace Internal
   template<typename Pair>
     struct extract1st
     {
-      typename Pair::first_type
+      const typename Pair::first_type&
       operator()(const Pair& p) const
       { return p.first; }
     };