diff options
Diffstat (limited to 'abseil-cpp/absl/container/flat_hash_set.h')
| -rw-r--r-- | abseil-cpp/absl/container/flat_hash_set.h | 41 |
1 files changed, 22 insertions, 19 deletions
diff --git a/abseil-cpp/absl/container/flat_hash_set.h b/abseil-cpp/absl/container/flat_hash_set.h index 81e145a..c789c7e 100644 --- a/abseil-cpp/absl/container/flat_hash_set.h +++ b/abseil-cpp/absl/container/flat_hash_set.h @@ -67,11 +67,15 @@ struct FlatHashSetPolicy; // // By default, `flat_hash_set` uses the `absl::Hash` hashing framework. All // fundamental and Abseil types that support the `absl::Hash` framework have a -// compatible equality operator for comparing insertions into `flat_hash_map`. +// compatible equality operator for comparing insertions into `flat_hash_set`. // If your type is not yet supported by the `absl::Hash` framework, see // absl/hash/hash.h for information on extending Abseil hashing to user-defined // types. // +// Using `absl::flat_hash_set` at interface boundaries in dynamically loaded +// libraries (e.g. .dll, .so) is unsupported due to way `absl::Hash` values may +// be randomized across dynamically loaded libraries. +// // NOTE: A `flat_hash_set` stores its keys directly inside its implementation // array to avoid memory indirection. Because a `flat_hash_set` is designed to // move data when rehashed, set keys will not retain pointer stability. If you @@ -106,7 +110,7 @@ class flat_hash_set public: // Constructors and Assignment Operators // - // A flat_hash_set supports the same overload set as `std::unordered_map` + // A flat_hash_set supports the same overload set as `std::unordered_set` // for construction and assignment: // // * Default constructor @@ -173,7 +177,7 @@ class flat_hash_set // available within the `flat_hash_set`. // // NOTE: this member function is particular to `absl::flat_hash_set` and is - // not provided in the `std::unordered_map` API. + // not provided in the `std::unordered_set` API. using Base::capacity; // flat_hash_set::empty() @@ -223,7 +227,11 @@ class flat_hash_set // iterator erase(const_iterator first, const_iterator last): // // Erases the elements in the open interval [`first`, `last`), returning an - // iterator pointing to `last`. + // iterator pointing to `last`. The special case of calling + // `erase(begin(), end())` resets the reserved growth such that if + // `reserve(N)` has previously been called and there has been no intervening + // call to `clear()`, then after calling `erase(begin(), end())`, it is safe + // to assume that inserting N elements will not cause a rehash. // // size_type erase(const key_type& key): // @@ -324,7 +332,7 @@ class flat_hash_set // flat_hash_set::merge() // - // Extracts elements from a given `source` flat hash map into this + // Extracts elements from a given `source` flat hash set into this // `flat_hash_set`. If the destination `flat_hash_set` already contains an // element with an equivalent key, that element is not extracted. using Base::merge; @@ -332,15 +340,15 @@ class flat_hash_set // flat_hash_set::swap(flat_hash_set& other) // // Exchanges the contents of this `flat_hash_set` with those of the `other` - // flat hash map, avoiding invocation of any move, copy, or swap operations on + // flat hash set, avoiding invocation of any move, copy, or swap operations on // individual elements. // // All iterators and references on the `flat_hash_set` remain valid, excepting // for the past-the-end iterator, which is invalidated. // // `swap()` requires that the flat hash set's hashing and key equivalence - // functions be Swappable, and are exchaged using unqualified calls to - // non-member `swap()`. If the map's allocator has + // functions be Swappable, and are exchanged using unqualified calls to + // non-member `swap()`. If the set's allocator has // `std::allocator_traits<allocator_type>::propagate_on_container_swap::value` // set to `true`, the allocators are also exchanged using an unqualified call // to non-member `swap()`; otherwise, the allocators are not swapped. @@ -395,14 +403,14 @@ class flat_hash_set // flat_hash_set::bucket_count() // // Returns the number of "buckets" within the `flat_hash_set`. Note that - // because a flat hash map contains all elements within its internal storage, + // because a flat hash set contains all elements within its internal storage, // this value simply equals the current capacity of the `flat_hash_set`. using Base::bucket_count; // flat_hash_set::load_factor() // // Returns the current load factor of the `flat_hash_set` (the average number - // of slots occupied with a value within the hash map). + // of slots occupied with a value within the hash set). using Base::load_factor; // flat_hash_set::max_load_factor() @@ -443,9 +451,11 @@ class flat_hash_set // erase_if(flat_hash_set<>, Pred) // // Erases all elements that satisfy the predicate `pred` from the container `c`. +// Returns the number of erased elements. template <typename T, typename H, typename E, typename A, typename Predicate> -void erase_if(flat_hash_set<T, H, E, A>& c, Predicate pred) { - container_internal::EraseIf(pred, &c); +typename flat_hash_set<T, H, E, A>::size_type erase_if( + flat_hash_set<T, H, E, A>& c, Predicate pred) { + return container_internal::EraseIf(pred, &c); } namespace container_internal { @@ -468,13 +478,6 @@ struct FlatHashSetPolicy { absl::allocator_traits<Allocator>::destroy(*alloc, slot); } - template <class Allocator> - static void transfer(Allocator* alloc, slot_type* new_slot, - slot_type* old_slot) { - construct(alloc, new_slot, std::move(*old_slot)); - destroy(alloc, old_slot); - } - static T& element(slot_type* slot) { return *slot; } template <class F, class... 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