/// @} group hashes
- // Hint about performance of hash functor. If not fast the hash-based
- // containers will cache the hash code.
- // Default behavior is to consider that hashers are fast unless specified
- // otherwise.
+ /** Hint about performance of hash functions.
+ *
+ * If a given hash function object is not fast, the hash-based containers
+ * will cache the hash code.
+ * The default behavior is to consider that hashers are fast unless specified
+ * otherwise.
+ *
+ * Users can specialize this for their own hash functions in order to force
+ * caching of hash codes in unordered containers. Specializing this trait
+ * affects the ABI of the unordered containers, so use it carefully.
+ */
template<typename _Hash>
struct __is_fast_hash : public std::true_type
{ };
#include <bits/hashtable_policy.h>
#include <bits/enable_special_members.h>
+#include <bits/stl_function.h> // __has_is_transparent_t
#if __cplusplus > 201402L
# include <bits/node_handle.h>
#endif
-#include <bits/functional_hash.h>
-#include <bits/stl_function.h> // equal_to, _Identity, _Select1st
namespace std _GLIBCXX_VISIBILITY(default)
{
#define _HASHTABLE_POLICY_H 1
#include <tuple> // for std::tuple, std::forward_as_tuple
+#include <bits/functional_hash.h> // for __is_fast_hash
#include <bits/stl_algobase.h> // for std::min, std::is_permutation.
+#include <bits/stl_pair.h> // for std::pair
#include <ext/aligned_buffer.h> // for __gnu_cxx::__aligned_buffer
#include <ext/alloc_traits.h> // for std::__alloc_rebind
#include <ext/numeric_traits.h> // for __gnu_cxx::__int_traits
#ifndef _UNORDERED_MAP_H
#define _UNORDERED_MAP_H
+#include <bits/hashtable.h>
+#include <bits/allocator.h>
+#include <bits/functional_hash.h> // hash
+#include <bits/stl_function.h> // equal_to
+
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
#ifndef _UNORDERED_SET_H
#define _UNORDERED_SET_H
+#include <bits/hashtable.h>
+#include <bits/allocator.h>
+#include <bits/functional_hash.h> // hash
+#include <bits/stl_function.h> // equal_to
+
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
# include <bits/c++0x_warning.h>
#else
-#include <type_traits>
#include <initializer_list>
-#include <bits/allocator.h>
-#include <ext/alloc_traits.h>
-#include <ext/aligned_buffer.h>
-#include <bits/stl_pair.h>
-#include <bits/stl_function.h> // equal_to, _Identity, _Select1st
-#include <bits/functional_hash.h>
-#include <bits/hashtable.h>
#include <bits/unordered_map.h>
#include <bits/range_access.h>
#include <bits/erase_if.h>
# include <bits/c++0x_warning.h>
#else
-#include <type_traits>
#include <initializer_list>
-#include <bits/allocator.h>
-#include <ext/alloc_traits.h>
-#include <ext/aligned_buffer.h>
-#include <bits/stl_pair.h>
-#include <bits/stl_function.h> // equal_to, _Identity, _Select1st
-#include <bits/functional_hash.h>
-#include <bits/hashtable.h>
#include <bits/unordered_set.h>
#include <bits/range_access.h>
#include <bits/erase_if.h>