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// -*- C++ -*-
// Copyright (C) 2005-2016 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.
// You should have received a copy of the GNU General Public License
// along with this library; see the file COPYING3. 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 assoc_container_traits_example.cpp
* A basic example showing how to use container_traits for querying container types
* for their behavior.
*/
/**
* The following example shows how to use container_traits in order to print
* out information on an associative container's behavior, e.g., its underlying
* data structure, or whether its objects guarantee storing entries sorted
* by key order.
*/
#include <iostream>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tag_and_trait.hpp>
using namespace std;
using namespace __gnu_pbds;
template<class DS_Category>
void
print_container_category(DS_Category);
template<>
void
print_container_category(cc_hash_tag)
{
cout << "Collision-chaining hash based associative-container:" << endl;
}
template<>
void
print_container_category(gp_hash_tag)
{
cout << "Probing hash based associative-container:" << endl;
}
template<>
void
print_container_category(rb_tree_tag)
{
cout << "Red-black tree associative-container:" << endl;
}
template<>
void
print_container_category(splay_tree_tag)
{
cout << "Splay tree associative-container:" << endl;
}
template<>
void
print_container_category(ov_tree_tag)
{
cout << "Ordered-vector tree associative-container:" << endl;
}
template<>
void
print_container_category(list_update_tag)
{
cout << "List-based associative-container:" << endl;
}
void
print_erase_can_throw(bool can)
{
if (can)
{
cout << "Erase can throw" << endl;
return;
}
cout << "Erase cannot throw" << endl;
}
void
print_order_preserving(bool does)
{
if (does)
{
cout << "Preserves order" << endl;
return;
}
cout << "Does not preserve order" << endl;
}
template<class Invalidation_Guarantee>
void
print_invalidation_guarantee(Invalidation_Guarantee);
template<>
void
print_invalidation_guarantee(basic_invalidation_guarantee)
{
cout << "Guarantees only that found references, pointers, and "
"iterators are valid as long as the container object is not "
"modified" << endl;
}
template<>
void
print_invalidation_guarantee(point_invalidation_guarantee)
{
cout << "Guarantees that found references, pointers, and "
"point_iterators are valid even if the container object "
"is modified" << endl;
}
template<>
void
print_invalidation_guarantee(range_invalidation_guarantee)
{
cout << "Guarantees that iterators remain valid even if the "
"container object is modified" << endl;
}
void
print_reverse_iteration(bool does)
{
if (does)
{
cout << "Supports reverse iteration" << endl;
return;
}
cout << "Does not support reverse iteration" << endl;
}
template<class DS_Traits>
void
print_container_attributes()
{
// First print out the data structure category.
print_container_category(typename DS_Traits::container_category());
// Now print the attributes of the container.
print_erase_can_throw(DS_Traits::erase_can_throw);
print_order_preserving(DS_Traits::order_preserving);
print_invalidation_guarantee(typename DS_Traits::invalidation_guarantee());
print_reverse_iteration(DS_Traits::reverse_iteration);
cout << endl << endl;
}
int
main()
{
{
// Print the attributes of a collision-chaining hash table.
typedef cc_hash_table< int, char> t;
print_container_attributes<container_traits<t> >();
}
{
// Print the attributes of a (general) probing hash table.
typedef gp_hash_table< int, char> t;
print_container_attributes<container_traits<t> >();
}
{
// Print the attributes of a red-black tree.
typedef tree< int, char> t;
print_container_attributes<container_traits<t> >();
}
{
// Print the attributes of a splay tree.
typedef
tree<
int,
char,
less<int>,
splay_tree_tag>
t;
print_container_attributes<container_traits<t> >();
}
{
// Print the attributes of an ordered-vector tree.
typedef
tree<
int,
char,
less<int>,
ov_tree_tag>
t;
print_container_attributes<container_traits<t> >();
}
{
// Print the attributes of an list-based container.
typedef list_update< int, char> t;
print_container_attributes<container_traits<t> >();
}
return 0;
}
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