types_traits.hpp
Go to the documentation of this file.
// -*- C++ -*-
// Copyright (C) 2005-2026 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the terms
// of the GNU General Public License as published by the Free Software
// Foundation; either version 3, or (at your option) any later
// version.
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
// Permission to use, copy, modify, sell, and distribute this software
// is hereby granted without fee, provided that the above copyright
// notice appears in all copies, and that both that copyright notice
// and this permission notice appear in supporting documentation. None
// of the above authors, nor IBM Haifa Research Laboratories, make any
// representation about the suitability of this software for any
// purpose. It is provided "as is" without express or implied
// warranty.
/**
* @file detail/types_traits.hpp
* Contains a traits class of types used by containers.
*/
#ifndef PB_DS_TYPES_TRAITS_HPP
#define PB_DS_TYPES_TRAITS_HPP
#include <algorithm>
#include <utility>
#include <ext/pb_ds/tag_and_trait.hpp>
#include <ext/pb_ds/detail/type_utils.hpp>
#include <memory>
namespace __gnu_pbds
{
namespace detail
{
/**
* @addtogroup traits Traits
* @{
*/
/// Primary template.
template<typename Key, typename Mapped>
struct no_throw_copies
{
static const bool __simple = is_simple<Key>::value
&& is_simple<Mapped>::value;
typedef integral_constant<int, __simple> indicator;
};
/// Specialization.
template<typename Key>
struct no_throw_copies<Key, null_type>
{
typedef integral_constant<int, is_simple<Key>::value> indicator;
};
/// Stored value.
template<typename _Tv>
struct stored_value
{
typedef _Tv value_type;
value_type m_value;
};
/// Stored hash.
template<typename _Th>
struct stored_hash
{
typedef _Th hash_type;
hash_type m_hash;
};
/// Primary template for representation of stored data.
/// Two types of data can be stored: value and hash.
template<typename _Tv, typename _Th, bool Store_Hash>
struct stored_data
: public stored_value<_Tv>, public stored_hash<_Th>
{ };
/// Specialization for representation of stored data of just value type.
template<typename _Tv, typename _Th>
struct stored_data<_Tv, _Th, false>
: public stored_value<_Tv>
{ };
/// Choose value_type to be a key/value pair or just a key.
template<typename Key, typename Mapped>
struct select_value_type
{
typedef std::pair<const Key, Mapped> type;
};
/// Specialization for sets where the key is the value_type.
template<typename Key>
struct select_value_type<Key, null_type>
{
typedef Key type;
};
/// Base class for conditionally defining a static data member.
template<typename Key, typename Mapped, typename _Alloc, bool Store_Hash>
struct maybe_null_type
{ };
/// Specialization that defines a static data member of type null_type.
template<typename Key,typename _Alloc, bool Store_Hash>
struct maybe_null_type<Key, null_type, _Alloc, Store_Hash>
{
static null_type s_null_type;
};
template<typename Key,typename _Alloc, bool Store_Hash>
null_type
maybe_null_type<Key, null_type, _Alloc, Store_Hash>::s_null_type;
/// Consistent API for accessing allocator-related types.
template<typename _Alloc, typename T>
struct rebind_traits
#if __cplusplus >= 201103L
: std::allocator_traits<_Alloc>::template rebind_traits<T>
{
using reference = T&;
using const_reference = const T&;
};
#else
: _Alloc::template rebind<T>::other
{
typedef typename _Alloc::template rebind<T>::other allocator_type;
};
#endif
/// Traits for abstract types.
template<typename Key, typename Mapped, typename _Alloc, bool Store_Hash>
struct types_traits
: public maybe_null_type<Key, Mapped, _Alloc, Store_Hash>
{
public:
typedef typename _Alloc::size_type size_type;
typedef typename select_value_type<Key, Mapped>::type value_type;
typedef Key key_type;
typedef Mapped mapped_type;
private:
typedef rebind_traits<_Alloc, value_type> __rebind_va;
typedef rebind_traits<_Alloc, key_type> __rebind_ka;
typedef rebind_traits<_Alloc, mapped_type> __rebind_ma;
typedef no_throw_copies<Key, Mapped> __nothrowcopy;
public:
typedef typename __rebind_ma::pointer mapped_pointer;
typedef typename __rebind_ma::const_pointer mapped_const_pointer;
typedef typename __rebind_ma::reference mapped_reference;
typedef typename __rebind_ma::const_reference mapped_const_reference;
typedef typename __rebind_va::pointer pointer;
typedef typename __rebind_va::const_pointer const_pointer;
typedef typename __rebind_va::reference reference;
typedef typename __rebind_va::const_reference const_reference;
typedef stored_data<value_type, size_type, Store_Hash> stored_data_type;
typedef typename __rebind_ka::pointer key_pointer;
typedef typename __rebind_ka::const_pointer key_const_pointer;
typedef typename __rebind_ka::reference key_reference;
typedef typename __rebind_ka::const_reference key_const_reference;
typedef std::pair<size_type, size_type> comp_hash;
typedef integral_constant<int, Store_Hash> store_extra;
typedef typename __nothrowcopy::indicator no_throw_indicator;
store_extra m_store_extra_indicator;
no_throw_indicator m_no_throw_copies_indicator;
};
///@}
} // namespace detail
} // namespace __gnu_pbds
#endif
algorithm
memory
utility
tag_and_trait.hpp
type_utils.hpp
__gnu_pbds
GNU extensions for policy-based data structures for public use.
Definition assoc_container.hpp:52
std::allocator_traits
Uniform interface to all allocator types.
Definition bits/alloc_traits.h:250
std::pair
Struct holding two objects of arbitrary type.
Definition stl_pair.h:304
__gnu_pbds::null_type
Represents no type, or absence of type, for template tricks.
Definition tag_and_trait.hpp:210
__gnu_pbds::detail::no_throw_copies
Primary template.
Definition types_traits.hpp:62
__gnu_pbds::detail::stored_value
Stored value.
Definition types_traits.hpp:79
__gnu_pbds::detail::stored_hash
Stored hash.
Definition types_traits.hpp:87
__gnu_pbds::detail::stored_data
Primary template for representation of stored data. Two types of data can be stored: value and hash.
Definition types_traits.hpp:97
__gnu_pbds::detail::select_value_type
Choose value_type to be a key/value pair or just a key.
Definition types_traits.hpp:108
__gnu_pbds::detail::maybe_null_type
Base class for conditionally defining a static data member.
Definition types_traits.hpp:122
__gnu_pbds::detail::rebind_traits
Consistent API for accessing allocator-related types.
Definition types_traits.hpp:140
__gnu_pbds::detail::types_traits
Traits for abstract types.
Definition types_traits.hpp:156