3 #include <unordered_map> 
    9   template <
typename Key, 
typename T,
 
   10             typename Hash, 
typename KeyEqual, 
typename Alloc>
 
   15     for (
size_t i = 0; i < m.bucket_count(); ++i)
 
   16       res += m.bucket_size(i);
 
   21   template <
typename Key, 
typename T,
 
   22             typename Hash, 
typename KeyEqual, 
typename Alloc>
 
   24   has(
const std::unordered_map<Key, T, Hash, KeyEqual, Alloc>& m,
 
   27     return m.find(k) != std::end(m);
 
size_t collision_count(const std::unordered_map< Key, T, Hash, KeyEqual, Alloc > &m)
Sum of bucket sizes. 
ATTRIBUTE_PURE bool has(const boost::container::flat_set< Key, Compare, Allocator > &s, const Key &e)
Whether e is member of s.