Silence warnings in tests about unused variables and local typedefs.

test/counting_iterator_test.cpp

@@ -153,7 +153,6 @@ template <class CountingIterator, class Value>
 void test_aux(CountingIterator start, CountingIterator finish, Value v1)
 {
     typedef typename CountingIterator::iterator_category category;
-    typedef typename CountingIterator::value_type value_type;
 
     // If it's a RandomAccessIterator we can do a few delicate tests
     category_test(start, finish, v1, category());