-// Copyright 2013 Google Inc. All Rights Reserved.
+// Copyright 2018 The Abseil Authors.
//
// 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
+// https://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,
// See the License for the specific language governing permissions and
// limitations under the License.
//
-// A btree_set<> implements the STL unique sorted associative container
-// interface (a.k.a set<>) using a btree. A btree_multiset<> implements the STL
-// multiple sorted associative container interface (a.k.a multiset<>) using a
-// btree. See btree.h for details of the btree implementation and caveats.
-
-#ifndef UTIL_BTREE_BTREE_SET_H__
-#define UTIL_BTREE_BTREE_SET_H__
+// -----------------------------------------------------------------------------
+// File: btree_set.h
+// -----------------------------------------------------------------------------
+//
+// This header file defines B-tree sets: sorted associative containers of
+// values.
+//
+// * `absl::btree_set<>`
+// * `absl::btree_multiset<>`
+//
+// These B-tree types are similar to the corresponding types in the STL
+// (`std::set` and `std::multiset`) and generally conform to the STL interfaces
+// of those types. However, because they are implemented using B-trees, they
+// are more efficient in most situations.
+//
+// Unlike `std::set` and `std::multiset`, which are commonly implemented using
+// red-black tree nodes, B-tree sets use more generic B-tree nodes able to hold
+// multiple values per node. Holding multiple values per node often makes
+// B-tree sets perform better than their `std::set` counterparts, because
+// multiple entries can be checked within the same cache hit.
+//
+// However, these types should not be considered drop-in replacements for
+// `std::set` and `std::multiset` as there are some API differences, which are
+// noted in this header file.
+//
+// Importantly, insertions and deletions may invalidate outstanding iterators,
+// pointers, and references to elements. Such invalidations are typically only
+// an issue if insertion and deletion operations are interleaved with the use of
+// more than one iterator, pointer, or reference simultaneously. For this
+// reason, `insert()` and `erase()` return a valid iterator at the current
+// position.
-#include <functional>
-#include <memory>
-#include <string>
+#pragma once
#include "btree.h"
#include "btree_container.h"
namespace btree {
-// The btree_set class is needed mainly for its constructors.
-template <typename Key,
- typename Compare = std::less<Key>,
- typename Alloc = std::allocator<Key>,
- int TargetNodeSize = 256>
-class btree_set : public btree_unique_container<
- btree<btree_set_params<Key, Compare, Alloc, TargetNodeSize> > > {
-
- typedef btree_set<Key, Compare, Alloc, TargetNodeSize> self_type;
- typedef btree_set_params<Key, Compare, Alloc, TargetNodeSize> params_type;
- typedef btree<params_type> btree_type;
- typedef btree_unique_container<btree_type> super_type;
+// btree::btree_set<>
+//
+// An `btree::btree_set<K>` is an ordered associative container of unique key
+// values designed to be a more efficient replacement for `std::set` (in most
+// cases).
+//
+// Keys are sorted using an (optional) comparison function, which defaults to
+// `std::less<K>`.
+//
+// An `btree::btree_set<K>` uses a default allocator of `std::allocator<K>` to
+// allocate (and deallocate) nodes, and construct and destruct values within
+// those nodes. You may instead specify a custom allocator `A` (which in turn
+// requires specifying a custom comparator `C`) as in
+// `btree::btree_set<K, C, A>`.
+//
+template <typename Key, typename Compare = std::less<Key>,
+ typename Alloc = std::allocator<Key>>
+class btree_set
+ : public internal::btree_set_container<
+ internal::btree<internal::set_params<
+ Key, Compare, Alloc, /*TargetNodeSize=*/256,
+ /*Multi=*/false>>> {
+ using Base = typename btree_set::btree_set_container;
public:
- typedef typename btree_type::key_compare key_compare;
- typedef typename btree_type::allocator_type allocator_type;
+ // Constructors and Assignment Operators
+ //
+ // A `btree_set` supports the same overload set as `std::set`
+ // for construction and assignment:
+ //
+ // * Default constructor
+ //
+ // btree::btree_set<std::string> set1;
+ //
+ // * Initializer List constructor
+ //
+ // btree::btree_set<std::string> set2 =
+ // {{"huey"}, {"dewey"}, {"louie"},};
+ //
+ // * Copy constructor
+ //
+ // btree::btree_set<std::string> set3(set2);
+ //
+ // * Copy assignment operator
+ //
+ // btree::btree_set<std::string> set4;
+ // set4 = set3;
+ //
+ // * Move constructor
+ //
+ // // Move is guaranteed efficient
+ // btree::btree_set<std::string> set5(std::move(set4));
+ //
+ // * Move assignment operator
+ //
+ // // May be efficient if allocators are compatible
+ // btree::btree_set<std::string> set6;
+ // set6 = std::move(set5);
+ //
+ // * Range constructor
+ //
+ // std::vector<std::string> v = {"a", "b"};
+ // btree::btree_set<std::string> set7(v.begin(), v.end());
+ btree_set() {}
+ using Base::Base;
- public:
- // Default constructor.
- btree_set(const key_compare &comp = key_compare(),
- const allocator_type &alloc = allocator_type())
- : super_type(comp, alloc) {
- }
+ // btree_set::begin()
+ //
+ // Returns an iterator to the beginning of the `btree_set`.
+ using Base::begin;
- // Copy constructor.
- btree_set(const self_type &x)
- : super_type(x) {
- }
+ // btree_set::cbegin()
+ //
+ // Returns a const iterator to the beginning of the `btree_set`.
+ using Base::cbegin;
- // Range constructor.
- template <class InputIterator>
- btree_set(InputIterator b, InputIterator e,
- const key_compare &comp = key_compare(),
- const allocator_type &alloc = allocator_type())
- : super_type(b, e, comp, alloc) {
- }
+ // btree_set::end()
+ //
+ // Returns an iterator to the end of the `btree_set`.
+ using Base::end;
+
+ // btree_set::cend()
+ //
+ // Returns a const iterator to the end of the `btree_set`.
+ using Base::cend;
+
+ // btree_set::empty()
+ //
+ // Returns whether or not the `btree_set` is empty.
+ using Base::empty;
+
+ // btree_set::max_size()
+ //
+ // Returns the largest theoretical possible number of elements within a
+ // `btree_set` under current memory constraints. This value can be thought
+ // of as the largest value of `std::distance(begin(), end())` for a
+ // `btree_set<Key>`.
+ using Base::max_size;
+
+ // btree_set::size()
+ //
+ // Returns the number of elements currently within the `btree_set`.
+ using Base::size;
+
+ // btree_set::clear()
+ //
+ // Removes all elements from the `btree_set`. Invalidates any references,
+ // pointers, or iterators referring to contained elements.
+ using Base::clear;
+
+ // btree_set::erase()
+ //
+ // Erases elements within the `btree_set`. Overloads are listed below.
+ //
+ // iterator erase(iterator position):
+ // iterator erase(const_iterator position):
+ //
+ // Erases the element at `position` of the `btree_set`, returning
+ // the iterator pointing to the element after the one that was erased
+ // (or end() if none exists).
+ //
+ // iterator erase(const_iterator first, const_iterator last):
+ //
+ // Erases the elements in the open interval [`first`, `last`), returning
+ // the iterator pointing to the element after the interval that was erased
+ // (or end() if none exists).
+ //
+ // template <typename K> size_type erase(const K& key):
+ //
+ // Erases the element with the matching key, if it exists, returning the
+ // number of elements erased.
+ using Base::erase;
+
+ // btree_set::insert()
+ //
+ // Inserts an element of the specified value into the `btree_set`,
+ // returning an iterator pointing to the newly inserted element, provided that
+ // an element with the given key does not already exist. If an insertion
+ // occurs, any references, pointers, or iterators are invalidated.
+ // Overloads are listed below.
+ //
+ // std::pair<iterator,bool> insert(const value_type& value):
+ //
+ // Inserts a value into the `btree_set`. Returns a pair consisting of an
+ // iterator to the inserted element (or to the element that prevented the
+ // insertion) and a bool denoting whether the insertion took place.
+ //
+ // std::pair<iterator,bool> insert(value_type&& value):
+ //
+ // Inserts a moveable value into the `btree_set`. Returns a pair
+ // consisting of an iterator to the inserted element (or to the element that
+ // prevented the insertion) and a bool denoting whether the insertion took
+ // place.
+ //
+ // iterator insert(const_iterator hint, const value_type& value):
+ // iterator insert(const_iterator hint, value_type&& value):
+ //
+ // Inserts a value, using the position of `hint` as a non-binding suggestion
+ // for where to begin the insertion search. Returns an iterator to the
+ // inserted element, or to the existing element that prevented the
+ // insertion.
+ //
+ // void insert(InputIterator first, InputIterator last):
+ //
+ // Inserts a range of values [`first`, `last`).
+ //
+ // void insert(std::initializer_list<init_type> ilist):
+ //
+ // Inserts the elements within the initializer list `ilist`.
+ using Base::insert;
+
+ // btree_set::emplace()
+ //
+ // Inserts an element of the specified value by constructing it in-place
+ // within the `btree_set`, provided that no element with the given key
+ // already exists.
+ //
+ // The element may be constructed even if there already is an element with the
+ // key in the container, in which case the newly constructed element will be
+ // destroyed immediately.
+ //
+ // If an insertion occurs, any references, pointers, or iterators are
+ // invalidated.
+ using Base::emplace;
+
+ // btree_set::emplace_hint()
+ //
+ // Inserts an element of the specified value by constructing it in-place
+ // within the `btree_set`, using the position of `hint` as a non-binding
+ // suggestion for where to begin the insertion search, and only inserts
+ // provided that no element with the given key already exists.
+ //
+ // The element may be constructed even if there already is an element with the
+ // key in the container, in which case the newly constructed element will be
+ // destroyed immediately.
+ //
+ // If an insertion occurs, any references, pointers, or iterators are
+ // invalidated.
+ using Base::emplace_hint;
+
+ // btree_set::merge()
+ //
+ // Extracts elements from a given `source` btree_set into this
+ // `btree_set`. If the destination `btree_set` already contains an
+ // element with an equivalent key, that element is not extracted.
+ using Base::merge;
+
+ // btree_set::swap(btree_set& other)
+ //
+ // Exchanges the contents of this `btree_set` with those of the `other`
+ // btree_set, avoiding invocation of any move, copy, or swap operations on
+ // individual elements.
+ //
+ // All iterators and references on the `btree_set` remain valid, excepting
+ // for the past-the-end iterator, which is invalidated.
+ using Base::swap;
+
+ // btree_set::contains()
+ //
+ // template <typename K> bool contains(const K& key) const:
+ //
+ // Determines whether an element comparing equal to the given `key` exists
+ // within the `btree_set`, returning `true` if so or `false` otherwise.
+ //
+ // Supports heterogeneous lookup, provided that the set is provided a
+ // compatible heterogeneous comparator.
+ using Base::contains;
+
+ // btree_set::count()
+ //
+ // template <typename K> size_type count(const K& key) const:
+ //
+ // Returns the number of elements comparing equal to the given `key` within
+ // the `btree_set`. Note that this function will return either `1` or `0`
+ // since duplicate elements are not allowed within a `btree_set`.
+ //
+ // Supports heterogeneous lookup, provided that the set is provided a
+ // compatible heterogeneous comparator.
+ using Base::count;
+
+ // btree_set::equal_range()
+ //
+ // Returns a closed range [first, last], defined by a `std::pair` of two
+ // iterators, containing all elements with the passed key in the
+ // `btree_set`.
+ using Base::equal_range;
+
+ // btree_set::find()
+ //
+ // template <typename K> iterator find(const K& key):
+ // template <typename K> const_iterator find(const K& key) const:
+ //
+ // Finds an element with the passed `key` within the `btree_set`.
+ //
+ // Supports heterogeneous lookup, provided that the set is provided a
+ // compatible heterogeneous comparator.
+ using Base::find;
+
+ // btree_set::get_allocator()
+ //
+ // Returns the allocator function associated with this `btree_set`.
+ using Base::get_allocator;
+
+ // btree_set::key_comp();
+ //
+ // Returns the key comparator associated with this `btree_set`.
+ using Base::key_comp;
+
+ // btree_set::value_comp();
+ //
+ // Returns the value comparator associated with this `btree_set`. The keys to
+ // sort the elements are the values themselves, therefore `value_comp` and its
+ // sibling member function `key_comp` are equivalent.
+ using Base::value_comp;
};
-template <typename K, typename C, typename A, int N>
-inline void swap(btree_set<K, C, A, N> &x, btree_set<K, C, A, N> &y) {
- x.swap(y);
+// btree::swap(btree::btree_set<>, btree::btree_set<>)
+//
+// Swaps the contents of two `btree::btree_set` containers.
+template <typename K, typename C, typename A>
+void swap(btree_set<K, C, A> &x, btree_set<K, C, A> &y) {
+ return x.swap(y);
}
-// The btree_multiset class is needed mainly for its constructors.
-template <typename Key,
- typename Compare = std::less<Key>,
- typename Alloc = std::allocator<Key>,
- int TargetNodeSize = 256>
-class btree_multiset : public btree_multi_container<
- btree<btree_set_params<Key, Compare, Alloc, TargetNodeSize> > > {
+// btree::erase_if(btree::btree_set<>, Pred)
+//
+// Erases all elements that satisfy the predicate pred from the container.
+template <typename K, typename C, typename A, typename Pred>
+void erase_if(btree_set<K, C, A> &set, Pred pred) {
+ for (auto it = set.begin(); it != set.end();) {
+ if (pred(*it)) {
+ it = set.erase(it);
+ } else {
+ ++it;
+ }
+ }
+}
- typedef btree_multiset<Key, Compare, Alloc, TargetNodeSize> self_type;
- typedef btree_set_params<Key, Compare, Alloc, TargetNodeSize> params_type;
- typedef btree<params_type> btree_type;
- typedef btree_multi_container<btree_type> super_type;
+// btree::btree_multiset<>
+//
+// An `btree::btree_multiset<K>` is an ordered associative container of
+// keys and associated values designed to be a more efficient replacement
+// for `std::multiset` (in most cases). Unlike `btree::btree_set`, a B-tree
+// multiset allows equivalent elements.
+//
+// Keys are sorted using an (optional) comparison function, which defaults to
+// `std::less<K>`.
+//
+// An `btree::btree_multiset<K>` uses a default allocator of `std::allocator<K>`
+// to allocate (and deallocate) nodes, and construct and destruct values within
+// those nodes. You may instead specify a custom allocator `A` (which in turn
+// requires specifying a custom comparator `C`) as in
+// `btree::btree_multiset<K, C, A>`.
+//
+template <typename Key, typename Compare = std::less<Key>,
+ typename Alloc = std::allocator<Key>>
+class btree_multiset
+ : public internal::btree_multiset_container<
+ internal::btree<internal::set_params<
+ Key, Compare, Alloc, /*TargetNodeSize=*/256,
+ /*Multi=*/true>>> {
+ using Base = typename btree_multiset::btree_multiset_container;
public:
- typedef typename btree_type::key_compare key_compare;
- typedef typename btree_type::allocator_type allocator_type;
+ // Constructors and Assignment Operators
+ //
+ // A `btree_multiset` supports the same overload set as `std::set`
+ // for construction and assignment:
+ //
+ // * Default constructor
+ //
+ // btree::btree_multiset<std::string> set1;
+ //
+ // * Initializer List constructor
+ //
+ // btree::btree_multiset<std::string> set2 =
+ // {{"huey"}, {"dewey"}, {"louie"},};
+ //
+ // * Copy constructor
+ //
+ // btree::btree_multiset<std::string> set3(set2);
+ //
+ // * Copy assignment operator
+ //
+ // btree::btree_multiset<std::string> set4;
+ // set4 = set3;
+ //
+ // * Move constructor
+ //
+ // // Move is guaranteed efficient
+ // btree::btree_multiset<std::string> set5(std::move(set4));
+ //
+ // * Move assignment operator
+ //
+ // // May be efficient if allocators are compatible
+ // btree::btree_multiset<std::string> set6;
+ // set6 = std::move(set5);
+ //
+ // * Range constructor
+ //
+ // std::vector<std::string> v = {"a", "b"};
+ // btree::btree_multiset<std::string> set7(v.begin(), v.end());
+ btree_multiset() {}
+ using Base::Base;
- public:
- // Default constructor.
- btree_multiset(const key_compare &comp = key_compare(),
- const allocator_type &alloc = allocator_type())
- : super_type(comp, alloc) {
- }
+ // btree_multiset::begin()
+ //
+ // Returns an iterator to the beginning of the `btree_multiset`.
+ using Base::begin;
- // Copy constructor.
- btree_multiset(const self_type &x)
- : super_type(x) {
- }
+ // btree_multiset::cbegin()
+ //
+ // Returns a const iterator to the beginning of the `btree_multiset`.
+ using Base::cbegin;
- // Range constructor.
- template <class InputIterator>
- btree_multiset(InputIterator b, InputIterator e,
- const key_compare &comp = key_compare(),
- const allocator_type &alloc = allocator_type())
- : super_type(b, e, comp, alloc) {
- }
+ // btree_multiset::end()
+ //
+ // Returns an iterator to the end of the `btree_multiset`.
+ using Base::end;
+
+ // btree_multiset::cend()
+ //
+ // Returns a const iterator to the end of the `btree_multiset`.
+ using Base::cend;
+
+ // btree_multiset::empty()
+ //
+ // Returns whether or not the `btree_multiset` is empty.
+ using Base::empty;
+
+ // btree_multiset::max_size()
+ //
+ // Returns the largest theoretical possible number of elements within a
+ // `btree_multiset` under current memory constraints. This value can be
+ // thought of as the largest value of `std::distance(begin(), end())` for a
+ // `btree_multiset<Key>`.
+ using Base::max_size;
+
+ // btree_multiset::size()
+ //
+ // Returns the number of elements currently within the `btree_multiset`.
+ using Base::size;
+
+ // btree_multiset::clear()
+ //
+ // Removes all elements from the `btree_multiset`. Invalidates any references,
+ // pointers, or iterators referring to contained elements.
+ using Base::clear;
+
+ // btree_multiset::erase()
+ //
+ // Erases elements within the `btree_multiset`. Overloads are listed below.
+ //
+ // iterator erase(iterator position):
+ // iterator erase(const_iterator position):
+ //
+ // Erases the element at `position` of the `btree_multiset`, returning
+ // the iterator pointing to the element after the one that was erased
+ // (or end() if none exists).
+ //
+ // iterator erase(const_iterator first, const_iterator last):
+ //
+ // Erases the elements in the open interval [`first`, `last`), returning
+ // the iterator pointing to the element after the interval that was erased
+ // (or end() if none exists).
+ //
+ // template <typename K> size_type erase(const K& key):
+ //
+ // Erases the elements matching the key, if any exist, returning the
+ // number of elements erased.
+ using Base::erase;
+
+ // btree_multiset::insert()
+ //
+ // Inserts an element of the specified value into the `btree_multiset`,
+ // returning an iterator pointing to the newly inserted element.
+ // Any references, pointers, or iterators are invalidated. Overloads are
+ // listed below.
+ //
+ // iterator insert(const value_type& value):
+ //
+ // Inserts a value into the `btree_multiset`, returning an iterator to the
+ // inserted element.
+ //
+ // iterator insert(value_type&& value):
+ //
+ // Inserts a moveable value into the `btree_multiset`, returning an iterator
+ // to the inserted element.
+ //
+ // iterator insert(const_iterator hint, const value_type& value):
+ // iterator insert(const_iterator hint, value_type&& value):
+ //
+ // Inserts a value, using the position of `hint` as a non-binding suggestion
+ // for where to begin the insertion search. Returns an iterator to the
+ // inserted element.
+ //
+ // void insert(InputIterator first, InputIterator last):
+ //
+ // Inserts a range of values [`first`, `last`).
+ //
+ // void insert(std::initializer_list<init_type> ilist):
+ //
+ // Inserts the elements within the initializer list `ilist`.
+ using Base::insert;
+
+ // btree_multiset::emplace()
+ //
+ // Inserts an element of the specified value by constructing it in-place
+ // within the `btree_multiset`. Any references, pointers, or iterators are
+ // invalidated.
+ using Base::emplace;
+
+ // btree_multiset::emplace_hint()
+ //
+ // Inserts an element of the specified value by constructing it in-place
+ // within the `btree_multiset`, using the position of `hint` as a non-binding
+ // suggestion for where to begin the insertion search.
+ //
+ // Any references, pointers, or iterators are invalidated.
+ using Base::emplace_hint;
+
+ // btree_multiset::extract()
+ //
+ // Extracts the indicated element, erasing it in the process, and returns it
+ // as a C++17-compatible node handle. Overloads are listed below.
+ //
+ // node_type extract(const_iterator position):
+ //
+ // Extracts the element at the indicated position and returns a node handle
+ // owning that extracted data.
+ //
+ // template <typename K> node_type extract(const K& x):
+ //
+ // Extracts the element with the key matching the passed key value and
+ // returns a node handle owning that extracted data. If the `btree_multiset`
+ // does not contain an element with a matching key, this function returns an
+ // empty node handle.
+ //
+ // NOTE: In this context, `node_type` refers to the C++17 concept of a
+ // move-only type that owns and provides access to the elements in associative
+ // containers (https://en.cppreference.com/w/cpp/container/node_handle).
+ // It does NOT refer to the data layout of the underlying btree.
+ using Base::extract;
+
+ // btree_multiset::merge()
+ //
+ // Extracts elements from a given `source` btree_multiset into this
+ // `btree_multiset`. If the destination `btree_multiset` already contains an
+ // element with an equivalent key, that element is not extracted.
+ using Base::merge;
+
+ // btree_multiset::swap(btree_multiset& other)
+ //
+ // Exchanges the contents of this `btree_multiset` with those of the `other`
+ // btree_multiset, avoiding invocation of any move, copy, or swap operations
+ // on individual elements.
+ //
+ // All iterators and references on the `btree_multiset` remain valid,
+ // excepting for the past-the-end iterator, which is invalidated.
+ using Base::swap;
+
+ // btree_multiset::contains()
+ //
+ // template <typename K> bool contains(const K& key) const:
+ //
+ // Determines whether an element comparing equal to the given `key` exists
+ // within the `btree_multiset`, returning `true` if so or `false` otherwise.
+ //
+ // Supports heterogeneous lookup, provided that the set is provided a
+ // compatible heterogeneous comparator.
+ using Base::contains;
+
+ // btree_multiset::count()
+ //
+ // template <typename K> size_type count(const K& key) const:
+ //
+ // Returns the number of elements comparing equal to the given `key` within
+ // the `btree_multiset`.
+ //
+ // Supports heterogeneous lookup, provided that the set is provided a
+ // compatible heterogeneous comparator.
+ using Base::count;
+
+ // btree_multiset::equal_range()
+ //
+ // Returns a closed range [first, last], defined by a `std::pair` of two
+ // iterators, containing all elements with the passed key in the
+ // `btree_multiset`.
+ using Base::equal_range;
+
+ // btree_multiset::find()
+ //
+ // template <typename K> iterator find(const K& key):
+ // template <typename K> const_iterator find(const K& key) const:
+ //
+ // Finds an element with the passed `key` within the `btree_multiset`.
+ //
+ // Supports heterogeneous lookup, provided that the set is provided a
+ // compatible heterogeneous comparator.
+ using Base::find;
+
+ // btree_multiset::get_allocator()
+ //
+ // Returns the allocator function associated with this `btree_multiset`.
+ using Base::get_allocator;
+
+ // btree_multiset::key_comp();
+ //
+ // Returns the key comparator associated with this `btree_multiset`.
+ using Base::key_comp;
+
+ // btree_multiset::value_comp();
+ //
+ // Returns the value comparator associated with this `btree_multiset`. The
+ // keys to sort the elements are the values themselves, therefore `value_comp`
+ // and its sibling member function `key_comp` are equivalent.
+ using Base::value_comp;
};
-template <typename K, typename C, typename A, int N>
-inline void swap(btree_multiset<K, C, A, N> &x,
- btree_multiset<K, C, A, N> &y) {
- x.swap(y);
+// btree::swap(btree::btree_multiset<>, btree::btree_multiset<>)
+//
+// Swaps the contents of two `btree::btree_multiset` containers.
+template <typename K, typename C, typename A>
+void swap(btree_multiset<K, C, A> &x, btree_multiset<K, C, A> &y) {
+ return x.swap(y);
}
-} // namespace btree
+// btree::erase_if(btree::btree_multiset<>, Pred)
+//
+// Erases all elements that satisfy the predicate pred from the container.
+template <typename K, typename C, typename A, typename Pred>
+void erase_if(btree_multiset<K, C, A> &set, Pred pred) {
+ for (auto it = set.begin(); it != set.end();) {
+ if (pred(*it)) {
+ it = set.erase(it);
+ } else {
+ ++it;
+ }
+ }
+}
-#endif // UTIL_BTREE_BTREE_SET_H__
+} // namespace btree
projects / ceph.git / blobdiff