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// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// The safe_btree_map<> is like btree_map<> except that it removes the caveat
// about insertion and deletion invalidating existing iterators at a small cost
// in making iterators larger and slower.
//
// Revalidation occurs whenever an iterator is accessed. References
// and pointers returned by safe_btree_map<> iterators are not stable,
// they are potentially invalidated by any non-const method on the map.
//
// BEGIN INCORRECT EXAMPLE
// for (auto i = safe_map->begin(); i != safe_map->end(); ++i) {
// const T *value = &i->second; // DO NOT DO THIS
// [code that modifies safe_map and uses value];
// }
// END INCORRECT EXAMPLE
#ifndef UTIL_BTREE_SAFE_BTREE_MAP_H__
#define UTIL_BTREE_SAFE_BTREE_MAP_H__
#include <functional>
#include <memory>
#include <utility>
#include "btree_container.h"
#include "btree_map.h"
#include "safe_btree.h"
namespace btree {
// The safe_btree_map class is needed mainly for its constructors.
template <typename Key, typename Value,
typename Compare = std::less<Key>,
typename Alloc = std::allocator<std::pair<const Key, Value> >,
int TargetNodeSize = 256>
class safe_btree_map : public btree_map_container<
safe_btree<btree_map_params<Key, Value, Compare, Alloc, TargetNodeSize> > > {
typedef safe_btree_map<Key, Value, Compare, Alloc, TargetNodeSize> self_type;
typedef btree_map_params<
Key, Value, Compare, Alloc, TargetNodeSize> params_type;
typedef safe_btree<params_type> btree_type;
typedef btree_map_container<btree_type> super_type;
public:
typedef typename btree_type::key_compare key_compare;
typedef typename btree_type::allocator_type allocator_type;
public:
// Default constructor.
safe_btree_map(const key_compare &comp = key_compare(),
const allocator_type &alloc = allocator_type())
: super_type(comp, alloc) {
}
// Copy constructor.
safe_btree_map(const self_type &x)
: super_type(x) {
}
safe_btree_map(self_type&& x) noexcept
: super_type(std::move(x)) {
}
self_type& operator=(safe_btree_map&& x) noexcept {
return static_cast<self_type&>(super_type::operator=(std::move(x)));
}
// Range constructor.
template <class InputIterator>
safe_btree_map(InputIterator b, InputIterator e,
const key_compare &comp = key_compare(),
const allocator_type &alloc = allocator_type())
: super_type(b, e, comp, alloc) {
}
};
template <typename K, typename V, typename C, typename A, int N>
inline void swap(safe_btree_map<K, V, C, A, N> &x,
safe_btree_map<K, V, C, A, N> &y) {
x.swap(y);
}
} // namespace btree
#endif // UTIL_BTREE_SAFE_BTREE_MAP_H__
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