///////////////////////// ankerl::unordered_dense::{map, set} /////////////////////////
// A fast & densely stored hashmap and hashset based on robin-hood backward shift deletion.
// Version 4.4.0
// https://github.com/martinus/unordered_dense
//
// Licensed under the MIT License <http://opensource.org/licenses/MIT>.
// SPDX-License-Identifier: MIT
// Copyright (c) 2022-2023 Martin Leitner-Ankerl <martin.ankerl@gmail.com>
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#ifndef ANKERL_UNORDERED_DENSE_H
#define ANKERL_UNORDERED_DENSE_H
// see https://semver.org/spec/v2.0.0.html
#define ANKERL_UNORDERED_DENSE_VERSION_MAJOR 4 // NOLINT(cppcoreguidelines-macro-usage) incompatible API changes
#define ANKERL_UNORDERED_DENSE_VERSION_MINOR 4 // NOLINT(cppcoreguidelines-macro-usage) backwards compatible functionality
#define ANKERL_UNORDERED_DENSE_VERSION_PATCH 0 // NOLINT(cppcoreguidelines-macro-usage) backwards compatible bug fixes
// API versioning with inline namespace, see https://www.foonathan.net/2018/11/inline-namespaces/
// NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
#define ANKERL_UNORDERED_DENSE_VERSION_CONCAT1(major, minor, patch) v##major##_##minor##_##patch
// NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
#define ANKERL_UNORDERED_DENSE_VERSION_CONCAT(major, minor, patch) ANKERL_UNORDERED_DENSE_VERSION_CONCAT1(major, minor, patch)
#define ANKERL_UNORDERED_DENSE_NAMESPACE \
ANKERL_UNORDERED_DENSE_VERSION_CONCAT( \
ANKERL_UNORDERED_DENSE_VERSION_MAJOR, ANKERL_UNORDERED_DENSE_VERSION_MINOR, ANKERL_UNORDERED_DENSE_VERSION_PATCH)
#if defined(_MSVC_LANG)
# define ANKERL_UNORDERED_DENSE_CPP_VERSION _MSVC_LANG
#else
# define ANKERL_UNORDERED_DENSE_CPP_VERSION __cplusplus
#endif
#if defined(__GNUC__)
// NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
# define ANKERL_UNORDERED_DENSE_PACK(decl) decl __attribute__((__packed__))
#elif defined(_MSC_VER)
// NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
# define ANKERL_UNORDERED_DENSE_PACK(decl) __pragma(pack(push, 1)) decl __pragma(pack(pop))
#endif
// exceptions
#if defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)
# define ANKERL_UNORDERED_DENSE_HAS_EXCEPTIONS() 1 // NOLINT(cppcoreguidelines-macro-usage)
#else
# define ANKERL_UNORDERED_DENSE_HAS_EXCEPTIONS() 0 // NOLINT(cppcoreguidelines-macro-usage)
#endif
#ifdef _MSC_VER
# define ANKERL_UNORDERED_DENSE_NOINLINE __declspec(noinline)
#else
# define ANKERL_UNORDERED_DENSE_NOINLINE __attribute__((noinline))
#endif
// defined in unordered_dense.cpp
#if !defined(ANKERL_UNORDERED_DENSE_EXPORT)
# define ANKERL_UNORDERED_DENSE_EXPORT
#endif
#if ANKERL_UNORDERED_DENSE_CPP_VERSION < 201703L
# error ankerl::unordered_dense requires C++17 or higher
#else
# include <array> // for array
# include <cstdint> // for uint64_t, uint32_t, uint8_t, UINT64_C
# include <cstring> // for size_t, memcpy, memset
# include <functional> // for equal_to, hash
# include <initializer_list> // for initializer_list
# include <iterator> // for pair, distance
# include <limits> // for numeric_limits
# include <memory> // for allocator, allocator_traits, shared_ptr
# include <optional> // for optional
# include <stdexcept> // for out_of_range
# include <string> // for basic_string
# include <string_view> // for basic_string_view, hash
# include <tuple> // for forward_as_tuple
# include <type_traits> // for enable_if_t, declval, conditional_t, ena...
# include <utility> // for forward, exchange, pair, as_const, piece...
# include <vector> // for vector
# if ANKERL_UNORDERED_DENSE_HAS_EXCEPTIONS() == 0
# include <cstdlib> // for abort
# endif
# if defined(__has_include)
# if __has_include(<memory_resource>)
# define ANKERL_UNORDERED_DENSE_PMR std::pmr // NOLINT(cppcoreguidelines-macro-usage)
# include <memory_resource> // for polymorphic_allocator
# elif __has_include(<experimental/memory_resource>)
# define ANKERL_UNORDERED_DENSE_PMR std::experimental::pmr // NOLINT(cppcoreguidelines-macro-usage)
# include <experimental/memory_resource> // for polymorphic_allocator
# endif
# endif
# if defined(_MSC_VER) && defined(_M_X64)
# include <intrin.h>
# pragma intrinsic(_umul128)
# endif
# if defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__clang__)
# define ANKERL_UNORDERED_DENSE_LIKELY(x) __builtin_expect(x, 1) // NOLINT(cppcoreguidelines-macro-usage)
# define ANKERL_UNORDERED_DENSE_UNLIKELY(x) __builtin_expect(x, 0) // NOLINT(cppcoreguidelines-macro-usage)
# else
# define ANKERL_UNORDERED_DENSE_LIKELY(x) (x) // NOLINT(cppcoreguidelines-macro-usage)
# define ANKERL_UNORDERED_DENSE_UNLIKELY(x) (x) // NOLINT(cppcoreguidelines-macro-usage)
# endif
namespace ankerl::unordered_dense {
inline namespace ANKERL_UNORDERED_DENSE_NAMESPACE {
namespace detail {
# if ANKERL_UNORDERED_DENSE_HAS_EXCEPTIONS()
// make sure this is not inlined as it is slow and dramatically enlarges code, thus making other
// inlinings more difficult. Throws are also generally the slow path.
[[noreturn]] inline ANKERL_UNORDERED_DENSE_NOINLINE void on_error_key_not_found() {
throw std::out_of_range("ankerl::unordered_dense::map::at(): key not found");
}
[[noreturn]] inline ANKERL_UNORDERED_DENSE_NOINLINE void on_error_bucket_overflow() {
throw std::overflow_error("ankerl::unordered_dense: reached max bucket size, cannot increase size");
}
[[noreturn]] inline ANKERL_UNORDERED_DENSE_NOINLINE void on_error_too_many_elements() {
throw std::out_of_range("ankerl::unordered_dense::map::replace(): too many elements");
}
# else
[[noreturn]] inline void on_error_key_not_found() {
abort();
}
[[noreturn]] inline void on_error_bucket_overflow() {
abort();
}
[[noreturn]] inline void on_error_too_many_elements() {
abort();
}
# endif
} // namespace detail
// hash ///////////////////////////////////////////////////////////////////////
// This is a stripped-down implementation of wyhash: https://github.com/wangyi-fudan/wyhash
// No big-endian support (because different values on different machines don't matter),
// hardcodes seed and the secret, reformats the code, and clang-tidy fixes.
namespace detail::wyhash {
inline void mum(uint64_t* a, uint64_t* b) {
# if defined(__SIZEOF_INT128__)
__uint128_t r = *a;
r *= *b;
*a = static_cast<uint64_t>(r);
*b = static_cast<uint64_t>(r >> 64U);
# elif defined(_MSC_VER) && defined(_M_X64)
*a = _umul128(*a, *b, b);
# else
uint64_t ha = *a >> 32U;
uint64_t hb = *b >> 32U;
uint64_t la = static_cast<uint32_t>(*a);
uint64_t lb = static_cast<uint32_t>(*b);
uint64_t hi{};
uint64_t lo{};
uint64_t rh = ha * hb;
uint64_t rm0 = ha * lb;
uint64_t rm1 = hb * la;
uint64_t rl = la * lb;
uint64_t t = rl + (rm0 << 32U);
auto c = static_cast<uint64_t>(t < rl);
lo = t + (rm1 << 32U);
c += static_cast<uint64_t>(lo < t);
hi = rh + (rm0 >> 32U) + (rm1 >> 32U) + c;
*a = lo;
*b = hi;
# endif
}
// multiply and xor mix function, aka MUM
[[nodiscard]] inline auto mix(uint64_t a, uint64_t b) -> uint64_t {
mum(&a, &b);
return a ^ b;
}
// read functions. WARNING: we don't care about endianness, so results are different on big endian!
[[nodiscard]] inline auto r8(const uint8_t* p) -> uint64_t {
uint64_t v{};
std::memcpy(&v, p, 8U);
return v;
}
[[nodiscard]] inline auto r4(const uint8_t* p) -> uint64_t {
uint32_t v{};
std::memcpy(&v, p, 4);
return v;
}
// reads 1, 2, or 3 bytes
[[nodiscard]] inline auto r3(const uint8_t* p, size_t k) -> uint64_t {
return (static_cast<uint64_t>(p[0]) << 16U) | (static_cast<uint64_t>(p[k >> 1U]) << 8U) | p[k - 1];
}
[[maybe_unused]] [[nodiscard]] inline auto hash(void const* key, size_t len) -> uint64_t {
static constexpr auto secret = std::array{UINT64_C(0xa0761d6478bd642f),
UINT64_C(0xe7037ed1a0b428db),
UINT64_C(0x8ebc6af09c88c6e3),
UINT64_C(0x589965cc75374cc3)};
auto const* p = static_cast<uint8_t const*>(key);
uint64_t seed = secret[0];
uint64_t a{};
uint64_t b{};
if (ANKERL_UNORDERED_DENSE_LIKELY(len <= 16)) {
if (ANKERL_UNORDERED_DENSE_LIKELY(len >= 4)) {
a = (r4(p) << 32U) | r4(p + ((len >> 3U) << 2U));
b = (r4(p + len - 4) << 32U) | r4(p + len - 4 - ((len >> 3U) << 2U));
} else if (ANKERL_UNORDERED_DENSE_LIKELY(len > 0)) {
a = r3(p, len);
b = 0;
} else {
a = 0;
b = 0;
}
} else {
size_t i = len;
if (ANKERL_UNORDERED_DENSE_UNLIKELY(i > 48)) {
uint64_t see1 = seed;
uint64_t see2 = seed;
do {
seed = mix(r8(p) ^ secret[1], r8(p + 8) ^ seed);
see1 = mix(r8(p + 16) ^ secret[2], r8(p + 24) ^ see1);
see2 = mix(r8(p + 32) ^ secret[3], r8(p + 40) ^ see2);
p += 48;
i -= 48;
} while (ANKERL_UNORDERED_DENSE_LIKELY(i > 48));
seed ^= see1 ^ see2;
}
while (ANKERL_UNORDERED_DENSE_UNLIKELY(i > 16)) {
seed = mix(r8(p) ^ secret[1], r8(p + 8) ^ seed);
i -= 16;
p += 16;
}
a = r8(p + i - 16);
b = r8(p + i - 8);
}
return mix(secret[1] ^ len, mix(a ^ secret[1], b ^ seed));
}
[[nodiscard]] inline auto hash(uint64_t x) -> uint64_t {
return detail::wyhash::mix(x, UINT64_C(0x9E3779B97F4A7C15));
}
} /* namespace detail::wyhash */
ANKERL_UNORDERED_DENSE_EXPORT template <typename T, typename Enable = void>
struct hash {
auto operator()(T const& obj) const noexcept(noexcept(std::declval<std::hash<T>>().operator()(std::declval<T const&>())))
-> uint64_t {
return std::hash<T>{}(obj);
}
};
template <typename CharT>
struct hash<std::basic_string<CharT>> {
using is_avalanching = void;
auto operator()(std::basic_string<CharT> const& str) const noexcept -> uint64_t {
return detail::wyhash::hash(str.data(), sizeof(CharT) * str.size());
}
};
template <typename CharT>
struct hash<std::basic_string_view<CharT>> {
using is_avalanching = void;
auto operator()(std::basic_string_view<CharT> const& sv) const noexcept -> uint64_t {
return detail::wyhash::hash(sv.data(), sizeof(CharT) * sv.size());
}
};
template <class T>
struct hash<T*> {
using is_avalanching = void;
auto operator()(T* ptr) const noexcept -> uint64_t {
// NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
return detail::wyhash::hash(reinterpret_cast<uintptr_t>(ptr));
}
};
template <class T>
struct hash<std::unique_ptr<T>> {
using is_avalanching = void;
auto operator()(std::unique_ptr<T> const& ptr) const noexcept -> uint64_t {
// NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
return detail::wyhash::hash(reinterpret_cast<uintptr_t>(ptr.get()));
}
};
template <class T>
struct hash<std::shared_ptr<T>> {
using is_avalanching = void;
auto operator()(std::shared_ptr<T> const& ptr) const noexcept -> uint64_t {
// NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
return detail::wyhash::hash(reinterpret_cast<uintptr_t>(ptr.get()));
}
};
template <typename Enum>
struct hash<Enum, typename std::enable_if<std::is_enum<Enum>::value>::type> {
using is_avalanching = void;
auto operator()(Enum e) const noexcept -> uint64_t {
using underlying = typename std::underlying_type_t<Enum>;
return detail::wyhash::hash(static_cast<underlying>(e));
}
};
template <typename... Args>
struct tuple_hash_helper {
// Converts the value into 64bit. If it is an integral type, just cast it. Mixing is doing the rest.
// If it isn't an integral we need to hash it.
template <typename Arg>
[[nodiscard]] constexpr static auto to64(Arg const& arg) -> uint64_t {
if constexpr (std::is_integral_v<Arg> || std::is_enum_v<Arg>) {
return static_cast<uint64_t>(arg);
} else {
return hash<Arg>{}(arg);
}
}
[[nodiscard]] static auto mix64(uint64_t state, uint64_t v) -> uint64_t {
return detail::wyhash::mix(state + v, uint64_t{0x9ddfea08eb382d69});
}
// Creates a buffer that holds all the data from each element of the tuple. If possible we memcpy the data directly. If
// not, we hash the object and use this for the array. Size of the array is known at compile time, and memcpy is optimized
// away, so filling the buffer is highly efficient. Finally, call wyhash with this buffer.
template <typename T, std::size_t... Idx>
[[nodiscard]] static auto calc_hash(T const& t, std::index_sequence<Idx...>) noexcept -> uint64_t {
auto h = uint64_t{};
((h = mix64(h, to64(std::get<Idx>(t)))), ...);
return h;
}
};
template <typename... Args>
struct hash<std::tuple<Args...>> : tuple_hash_helper<Args...> {
using is_avalanching = void;
auto operator()(std::tuple<Args...> const& t) const noexcept -> uint64_t {
return tuple_hash_helper<Args...>::calc_hash(t, std::index_sequence_for<Args...>{});
}
};
template <typename A, typename B>
struct hash<std::pair<A, B>> : tuple_hash_helper<A, B> {
using is_avalanching = void;
auto operator()(std::pair<A, B> const& t) const noexcept -> uint64_t {
return tuple_hash_helper<A, B>::calc_hash(t, std::index_sequence_for<A, B>{});
}
};
// NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
# define ANKERL_UNORDERED_DENSE_HASH_STATICCAST(T) \
template <> \
struct hash<T> { \
using is_avalanching = void; \
auto operator()(T const& obj) const noexcept -> uint64_t { \
return detail::wyhash::hash(static_cast<uint64_t>(obj)); \
} \
}
# if defined(__GNUC__) && !defined(__clang__)
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wuseless-cast"
# endif
// see https://en.cppreference.com/w/cpp/utility/hash
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(bool);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(char);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(signed char);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(unsigned char);
# if ANKERL_UNORDERED_DENSE_CPP_VERSION >= 202002L && defined(__cpp_char8_t)
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(char8_t);
# endif
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(char16_t);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(char32_t);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(wchar_t);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(short);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(unsigned short);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(int);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(unsigned int);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(long);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(long long);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(unsigned long);
ANKERL_UNORDERED_DENSE_HASH_STATICCAST(unsigned long long);
# if defined(__GNUC__) && !defined(__clang__)
# pragma GCC diagnostic pop
# endif
// bucket_type //////////////////////////////////////////////////////////
namespace bucket_type {
struct standard {
static constexpr uint32_t dist_inc = 1U << 8U; // skip 1 byte fingerprint
static constexpr uint32_t fingerprint_mask = dist_inc - 1; // mask for 1 byte of fingerprint
uint32_t m_dist_and_fingerprint; // upper 3 byte: distance to original bucket. lower byte: fingerprint from hash
uint32_t m_value_idx; // index into the m_values vector.
};
ANKERL_UNORDERED_DENSE_PACK(struct big {
static constexpr uint32_t dist_inc = 1U << 8U; // skip 1 byte fingerprint
static constexpr uint32_t fingerprint_mask = dist_inc - 1; // mask for 1 byte of fingerprint
uint32_t m_dist_and_fingerprint; // upper 3 byte: distance to original bucket. lower byte: fingerprint from hash
size_t m_value_idx; // index into the m_values vector.
});
} /* namespace bucket_type */
namespace detail {
struct nonesuch {};
template <class Default, class AlwaysVoid, template <class...> class Op, class... Args>
struct detector {
using value_t = std::false_type;
using type = Default;
};
template <class Default, template <class...> class Op, class... Args>
struct detector<Default, std::void_t<Op<Args...>>, Op, Args...> {
using value_t = std::true_type;
using type = Op<Args...>;
};
template <template <class...> class Op, class... Args>
using is_detected = typename detail::detector<detail::nonesuch, void, Op, Args...>::value_t;
template <template <class...> class Op, class... Args>
constexpr bool is_detected_v = is_detected<Op, Args...>::value;
template <typename T>
using detect_avalanching = typename T::is_avalanching;
template <typename T>
using detect_is_transparent = typename T::is_transparent;
template <typename T>
using detect_iterator = typename T::iterator;
template <typename T>
using detect_reserve = decltype(std::declval<T&>().reserve(size_t{}));
// enable_if helpers
template <typename Mapped>
constexpr bool is_map_v = !std::is_void_v<Mapped>;
// clang-format off
template <typename Hash, typename KeyEqual>
constexpr bool is_transparent_v = is_detected_v<detect_is_transparent, Hash> && is_detected_v<detect_is_transparent, KeyEqual>;
// clang-format on
template <typename From, typename To1, typename To2>
constexpr bool is_neither_convertible_v = !std::is_convertible_v<From, To1> && !std::is_convertible_v<From, To2>;
template <typename T>
constexpr bool has_reserve = is_detected_v<detect_reserve, T>;
// base type for map has mapped_type
template <class T>
struct base_table_type_map {
using mapped_type = T;
};
// base type for set doesn't have mapped_type
struct base_table_type_set {};
} /* namespace detail */
// Very much like std::deque, but faster for indexing (in most cases). As of now this doesn't implement the full std::vector
// API, but merely what's necessary to work as an underlying container for ankerl::unordered_dense::{map, set}.
// It allocates blocks of equal size and puts them into the m_blocks vector. That means it can grow simply by adding a new
// block to the back of m_blocks, and doesn't double its size like an std::vector. The disadvantage is that memory is not
// linear and thus there is one more indirection necessary for indexing.
template <typename T, typename Allocator = std::allocator<T>, size_t MaxSegmentSizeBytes = 4096>
class segmented_vector {
template <bool IsConst>
class iter_t;
public:
using allocator_type = Allocator;
using pointer = typename std::allocator_traits<allocator_type>::pointer;
using const_pointer = typename std::allocator_traits<allocator_type>::const_pointer;
using difference_type = typename std::allocator_traits<allocator_type>::difference_type;
using value_type = T;
using size_type = std::size_t;
using reference = T&;
using const_reference = T const&;
using iterator = iter_t<false>;
using const_iterator = iter_t<true>;
private:
using vec_alloc = typename std::allocator_traits<Allocator>::template rebind_alloc<pointer>;
std::vector<pointer, vec_alloc> m_blocks{};
size_t m_size{};
// Calculates the maximum number for x in (s << x) <= max_val
static constexpr auto num_bits_closest(size_t max_val, size_t s) -> size_t {
auto f = size_t{0};
while (s << (f + 1) <= max_val) {
++f;
}
return f;
}
using self_t = segmented_vector<T, Allocator, MaxSegmentSizeBytes>;
static constexpr auto num_bits = num_bits_closest(MaxSegmentSizeBytes, sizeof(T));
static constexpr auto num_elements_in_block = 1U << num_bits;
static constexpr auto mask = num_elements_in_block - 1U;
/**
* Iterator class doubles as const_iterator and iterator
*/
template <bool IsConst>
class iter_t {
using ptr_t = typename std::conditional_t<IsConst, segmented_vector::const_pointer const*, segmented_vector::pointer*>;
ptr_t m_data{};
size_t m_idx{};
template <bool B>
friend class iter_t;
public:
using difference_type = segmented_vector::difference_type;
using value_type = T;
using reference = typename std::conditional_t<IsConst, value_type const&, value_type&>;
using pointer = typename std::conditional_t<IsConst, segmented_vector::const_pointer, segmented_vector::pointer>;
using iterator_category = std::forward_iterator_tag;
iter_t() noexcept = default;
template <bool OtherIsConst, typename = typename std::enable_if<IsConst && !OtherIsConst>::type>
// NOLINTNEXTLINE(google-explicit-constructor,hicpp-explicit-conversions)
constexpr iter_t(iter_t<OtherIsConst> const& other) noexcept
: m_data(other.m_data)
, m_idx(other.m_idx) {}
constexpr iter_t(ptr_t data, size_t idx) noexcept
: m_data(data)
, m_idx(idx) {}
template <bool OtherIsConst, typename = typename std::enable_if<IsConst && !OtherIsConst>::type>
constexpr auto operator=(iter_t<OtherIsConst> const& other) noexcept -> iter_t& {
m_data = other.m_data;
m_idx = other.m_idx;
return *this;
}
constexpr auto operator++() noexcept -> iter_t& {
++m_idx;
return *this;
}
constexpr auto operator+(difference_type diff) noexcept -> iter_t {
return {m_data, static_cast<size_t>(static_cast<difference_type>(m_idx) + diff)};
}
template <bool OtherIsConst>
constexpr auto operator-(iter_t<OtherIsConst> const& other) noexcept -> difference_type {
return static_cast<difference_type>(m_idx) - static_cast<difference_type>(other.m_idx);
}
constexpr auto operator*() const noexcept -> reference {
return m_data[m_idx >> num_bits][m_idx & mask];
}
constexpr auto operator->() const noexcept -> pointer {
return &m_data[m_idx >> num_bits][m_idx & mask];
}
template <bool O>
constexpr auto operator==(iter_t<O> const& o) const noexcept -> bool {
return m_idx == o.m_idx;
}
template <bool O>
constexpr auto operator!=(iter_t<O> const& o) const noexcept -> bool {
return !(*this == o);
}
};
// slow path: need to allocate a new segment every once in a while
void increase_capacity() {
auto ba = Allocator(m_blocks.get_allocator());
pointer block = std::allocator_traits<Allocator>::allocate(ba, num_elements_in_block);
m_blocks.push_back(block);
}
// Moves everything from other
void append_everything_from(segmented_vector&& other) {
reserve(size() + other.size());
for (auto&& o : other) {
emplace_back(std::move(o));
}
}
// Copies everything from other
void append_everything_from(segmented_vector const& other) {
reserve(size() + other.size());
for (auto const& o : other) {
emplace_back(o);
}
}
void dealloc() {
auto ba = Allocator(m_blocks.get_allocator());
for (auto ptr : m_blocks) {
std::allocator_traits<Allocator>::deallocate(ba, ptr, num_elements_in_block);
}
}
[[nodiscard]] static constexpr auto calc_num_blocks_for_capacity(size_t capacity) {
return (capacity + num_elements_in_block - 1U) / num_elements_in_block;
}
public:
segmented_vector() = default;
// NOLINTNEXTLINE(google-explicit-constructor,hicpp-explicit-conversions)
segmented_vector(Allocator alloc)
: m_blocks(vec_alloc(alloc)) {}
segmented_vector(segmented_vector&& other, Allocator alloc)
: segmented_vector(alloc) {
*this = std::move(other);
}
segmented_vector(segmented_vector const& other, Allocator alloc)
: m_blocks(vec_alloc(alloc)) {
append_everything_from(other);
}
segmented_vector(segmented_vector&& other) noexcept
: segmented_vector(std::move(other), get_allocator()) {}
segmented_vector(segmented_vector const& other) {
append_everything_from(other);
}
auto operator=(segmented_vector const& other) -> segmented_vector& {
if (this == &other) {
return *this;
}
clear();
append_everything_from(other);
return *this;
}
auto operator=(segmented_vector&& other) noexcept -> segmented_vector& {
clear();
dealloc();
if (other.get_allocator() == get_allocator()) {
m_blocks = std::move(other.m_blocks);
m_size = std::exchange(other.m_size, {});
} else {
// make sure to construct with other's allocator!
m_blocks = std::vector<pointer, vec_alloc>(vec_alloc(other.get_allocator()));
append_everything_from(std::move(other));
}
return *this;
}
~segmented_vector() {
clear();
dealloc();
}
[[nodiscard]] constexpr auto size() const -> size_t {
return m_size;
}
[[nodiscard]] constexpr auto capacity() const -> size_t {
return m_blocks.size() * num_elements_in_block;
}
// Indexing is highly performance critical
[[nodiscard]] constexpr auto operator[](size_t i) const noexcept -> T const& {
return m_blocks[i >> num_bits][i & mask];
}
[[nodiscard]] constexpr auto operator[](size_t i) noexcept -> T& {
return m_blocks[i >> num_bits][i & mask];
}
[[nodiscard]] constexpr auto begin() -> iterator {
return {m_blocks.data(), 0U};
}
[[nodiscard]] constexpr auto begin() const -> const_iterator {
return {m_blocks.data(), 0U};
}
[[nodiscard]] constexpr auto cbegin() const -> const_iterator {
return {m_blocks.data(), 0U};
}
[[nodiscard]] constexpr auto end() -> iterator {
return {m_blocks.data(), m_size};
}
[[nodiscard]] constexpr auto end() const -> const_iterator {
return {m_blocks.data(), m_size};
}
[[nodiscard]] constexpr auto cend() const -> const_iterator {
return {m_blocks.data(), m_size};
}
[[nodiscard]] constexpr auto back() -> reference {
return operator[](m_size - 1);
}
[[nodiscard]] constexpr auto back() const -> const_reference {
return operator[](m_size - 1);
}
void pop_back() {
back().~T();
--m_size;
}
[[nodiscard]] auto empty() const {
return 0 == m_size;
}
void reserve(size_t new_capacity) {
m_blocks.reserve(calc_num_blocks_for_capacity(new_capacity));
while (new_capacity > capacity()) {
increase_capacity();
}
}
[[nodiscard]] auto get_allocator() const -> allocator_type {
return allocator_type{m_blocks.get_allocator()};
}
template <class... Args>
auto emplace_back(Args&&... args) -> reference {
if (m_size == capacity()) {
increase_capacity();
}
auto* ptr = static_cast<void*>(&operator[](m_size));
auto& ref = *new (ptr) T(std::forward<Args>(args)...);
++m_size;
return ref;
}
void clear() {
if constexpr (!std::is_trivially_destructible_v<T>) {
for (size_t i = 0, s = size(); i < s; ++i) {
operator[](i).~T();
}
}
m_size = 0;
}
void shrink_to_fit() {
auto ba = Allocator(m_blocks.get_allocator());
auto num_blocks_required = calc_num_blocks_for_capacity(m_size);
while (m_blocks.size() > num_blocks_required) {
std::allocator_traits<Allocator>::deallocate(ba, m_blocks.back(), num_elements_in_block);
m_blocks.pop_back();
}
m_blocks.shrink_to_fit();
}
};
namespace detail {
// This is it, the table. Doubles as map and set, and uses `void` for T when its used as a set.
template <class Key,
class T, // when void, treat it as a set.
class Hash,
class KeyEqual,
class AllocatorOrContainer,
class Bucket,
bool IsSegmented>
class table : public std::conditional_t<is_map_v<T>, base_table_type_map<T>, base_table_type_set> {
using underlying_value_type = typename std::conditional_t<is_map_v<T>, std::pair<Key, T>, Key>;
using underlying_container_type = std::conditional_t<IsSegmented,
segmented_vector<underlying_value_type, AllocatorOrContainer>,
std::vector<underlying_value_type, AllocatorOrContainer>>;
public:
using value_container_type = std::
conditional_t<is_detected_v<detect_iterator, AllocatorOrContainer>, AllocatorOrContainer, underlying_container_type>;
private:
using bucket_alloc =
typename std::allocator_traits<typename value_container_type::allocator_type>::template rebind_alloc<Bucket>;
using bucket_alloc_traits = std::allocator_traits<bucket_alloc>;
static constexpr uint8_t initial_shifts = 64 - 2; // 2^(64-m_shift) number of buckets
static constexpr float default_max_load_factor = 0.8F;
public:
using key_type = Key;
using value_type = typename value_container_type::value_type;
using size_type = typename value_container_type::size_type;
using difference_type = typename value_container_type::difference_type;
using hasher = Hash;
using key_equal = KeyEqual;
using allocator_type = typename value_container_type::allocator_type;
using reference = typename value_container_type::reference;
using const_reference = typename value_container_type::const_reference;
using pointer = typename value_container_type::pointer;
using const_pointer = typename value_container_type::const_pointer;
using const_iterator = typename value_container_type::const_iterator;
using iterator = std::conditional_t<is_map_v<T>, typename value_container_type::iterator, const_iterator>;
using bucket_type = Bucket;
private:
using value_idx_type = decltype(Bucket::m_value_idx);
using dist_and_fingerprint_type = decltype(Bucket::m_dist_and_fingerprint);
static_assert(std::is_trivially_destructible_v<Bucket>, "assert there's no need to call destructor / std::destroy");
static_assert(std::is_trivially_copyable_v<Bucket>, "assert we can just memset / memcpy");
value_container_type m_values{}; // Contains all the key-value pairs in one densely stored container. No holes.
using bucket_pointer = typename std::allocator_traits<bucket_alloc>::pointer;
bucket_pointer m_buckets{};
size_t m_num_buckets = 0;
size_t m_max_bucket_capacity = 0;
float m_max_load_factor = default_max_load_factor;
Hash m_hash{};
KeyEqual m_equal{};
uint8_t m_shifts = initial_shifts;
[[nodiscard]] auto next(value_idx_type bucket_idx) const -> value_idx_type {
return ANKERL_UNORDERED_DENSE_UNLIKELY(bucket_idx + 1U == m_num_buckets)
? 0
: static_cast<value_idx_type>(bucket_idx + 1U);
}
// Helper to access bucket through pointer types
[[nodiscard]] static constexpr auto at(bucket_pointer bucket_ptr, size_t offset) -> Bucket& {
return *(bucket_ptr + static_cast<typename std::allocator_traits<bucket_alloc>::difference_type>(offset));
}
// use the dist_inc and dist_dec functions so that uint16_t types work without warning
[[nodiscard]] static constexpr auto dist_inc(dist_and_fingerprint_type x) -> dist_and_fingerprint_type {
return static_cast<dist_and_fingerprint_type>(x + Bucket::dist_inc);
}
[[nodiscard]] static constexpr auto dist_dec(dist_and_fingerprint_type x) -> dist_and_fingerprint_type {
return static_cast<dist_and_fingerprint_type>(x - Bucket::dist_inc);
}
// The goal of mixed_hash is to always produce a high quality 64bit hash.
template <typename K>
[[nodiscard]] constexpr auto mixed_hash(K const& key) const -> uint64_t {
if constexpr (is_detected_v<detect_avalanching, Hash>) {
// we know that the hash is good because is_avalanching.
if constexpr (sizeof(decltype(m_hash(key))) < sizeof(uint64_t)) {
// 32bit hash and is_avalanching => multiply with a constant to avalanche bits upwards
return m_hash(key) * UINT64_C(0x9ddfea08eb382d69);
} else {
// 64bit and is_avalanching => only use the hash itself.
return m_hash(key);
}
} else {
// not is_avalanching => apply wyhash
return wyhash::hash(m_hash(key));
}
}
[[nodiscard]] constexpr auto dist_and_fingerprint_from_hash(uint64_t hash) const -> dist_and_fingerprint_type {
return Bucket::dist_inc | (static_cast<dist_and_fingerprint_type>(hash) & Bucket::fingerprint_mask);
}
[[nodiscard]] constexpr auto bucket_idx_from_hash(uint64_t hash) const -> value_idx_type {
return static_cast<value_idx_type>(hash >> m_shifts);
}
[[nodiscard]] static constexpr auto get_key(value_type const& vt) -> key_type const& {
if constexpr (is_map_v<T>) {
return vt.first;
} else {
return vt;
}
}
template <typename K>
[[nodiscard]] auto next_while_less(K const& key) const -> Bucket {
auto hash = mixed_hash(key);
auto dist_and_fingerprint = dist_and_fingerprint_from_hash(hash);
auto bucket_idx = bucket_idx_from_hash(hash);
while (dist_and_fingerprint < at(m_buckets, bucket_idx).m_dist_and_fingerprint) {
dist_and_fingerprint = dist_inc(dist_and_fingerprint);
bucket_idx = next(bucket_idx);
}
return {dist_and_fingerprint, bucket_idx};
}
void place_and_shift_up(Bucket bucket, value_idx_type place) {
while (0 != at(m_buckets, place).m_dist_and_fingerprint) {
bucket = std::exchange(at(m_buckets, place), bucket);
bucket.m_dist_and_fingerprint = dist_inc(bucket.m_dist_and_fingerprint);
place = next(place);
}
at(m_buckets, place) = bucket;
}
[[nodiscard]] static constexpr auto calc_num_buckets(uint8_t shifts) -> size_t {
return (std::min)(max_bucket_count(), size_t{1} << (64U - shifts));
}
[[nodiscard]] constexpr auto calc_shifts_for_size(size_t s) const -> uint8_t {
auto shifts = initial_shifts;
while (shifts > 0 && static_cast<size_t>(static_cast<float>(calc_num_buckets(shifts)) * max_load_factor()) < s) {
--shifts;
}
return shifts;
}
// assumes m_values has data, m_buckets=m_buckets_end=nullptr, m_shifts is INITIAL_SHIFTS
void copy_buckets(table const& other) {
// assumes m_values has already the correct data copied over.
if (empty()) {
// when empty, at least allocate an initial buckets and clear them.
allocate_buckets_from_shift();
clear_buckets();
} else {
m_shifts = other.m_shifts;
allocate_buckets_from_shift();
std::memcpy(m_buckets, other.m_buckets, sizeof(Bucket) * bucket_count());
}
}
/**
* True when no element can be added any more without increasing the size
*/
[[nodiscard]] auto is_full() const -> bool {
return size() > m_max_bucket_capacity;
}
void deallocate_buckets() {
auto ba = bucket_alloc(m_values.get_allocator());
if (nullptr != m_buckets) {
bucket_alloc_traits::deallocate(ba, m_buckets, bucket_count());
m_buckets = nullptr;
}
m_num_buckets = 0;
m_max_bucket_capacity = 0;
}
void allocate_buckets_from_shift() {
auto ba = bucket_alloc(m_values.get_allocator());
m_num_buckets = calc_num_buckets(m_shifts);
m_buckets = bucket_alloc_traits::allocate(ba, m_num_buckets);
if (m_num_buckets == max_bucket_count()) {
// reached the maximum, make sure we can use each bucket
m_max_bucket_capacity = max_bucket_count();
} else {
m_max_bucket_capacity = static_cast<value_idx_type>(static_cast<float>(m_num_buckets) * max_load_factor());
}
}
void clear_buckets() {
if (m_buckets != nullptr) {
std::memset(&*m_buckets, 0, sizeof(Bucket) * bucket_count());
}
}
void clear_and_fill_buckets_from_values() {
clear_buckets();
for (value_idx_type value_idx = 0, end_idx = static_cast<value_idx_type>(m_values.size()); value_idx < end_idx;
++value_idx) {
auto const& key = get_key(m_values[value_idx]);
auto [dist_and_fingerprint, bucket] = next_while_less(key);
// we know for certain that key has not yet been inserted, so no need to check it.
place_and_shift_up({dist_and_fingerprint, value_idx}, bucket);
}
}
void increase_size() {
if (m_max_bucket_capacity == max_bucket_count()) {
// remove the value again, we can't add it!
m_values.pop_back();
on_error_bucket_overflow();
}
--m_shifts;
deallocate_buckets();
allocate_buckets_from_shift();
clear_and_fill_buckets_from_values();
}
template <typename Op>
void do_erase(value_idx_type bucket_idx, Op handle_erased_value) {
auto const value_idx_to_remove = at(m_buckets, bucket_idx).m_value_idx;
// shift down until either empty or an element with correct spot is found
auto next_bucket_idx = next(bucket_idx);
while (at(m_buckets, next_bucket_idx).m_dist_and_fingerprint >= Bucket::dist_inc * 2) {
at(m_buckets, bucket_idx) = {dist_dec(at(m_buckets, next_bucket_idx).m_dist_and_fingerprint),
at(m_buckets, next_bucket_idx).m_value_idx};
bucket_idx = std::exchange(next_bucket_idx, next(next_bucket_idx));
}
at(m_buckets, bucket_idx) = {};
handle_erased_value(std::move(m_values[value_idx_to_remove]));
// update m_values
if (value_idx_to_remove != m_values.size() - 1) {
// no luck, we'll have to replace the value with the last one and update the index accordingly
auto& val = m_values[value_idx_to_remove];
val = std::move(m_values.back());
// update the values_idx of the moved entry. No need to play the info game, just look until we find the values_idx
auto mh = mixed_hash(get_key(val));
bucket_idx = bucket_idx_from_hash(mh);
auto const values_idx_back = static_cast<value_idx_type>(m_values.size() - 1);
while (values_idx_back != at(m_buckets, bucket_idx).m_value_idx) {
bucket_idx = next(bucket_idx);
}
at(m_buckets, bucket_idx).m_value_idx = value_idx_to_remove;
}
m_values.pop_back();
}
template <typename K, typename Op>
auto do_erase_key(K&& key, Op handle_erased_value) -> size_t {
if (empty()) {
return 0;
}
auto [dist_and_fingerprint, bucket_idx] = next_while_less(key);
while (dist_and_fingerprint == at(m_buckets, bucket_idx).m_dist_and_fingerprint &&
!m_equal(key, get_key(m_values[at(m_buckets, bucket_idx).m_value_idx]))) {
dist_and_fingerprint = dist_inc(dist_and_fingerprint);
bucket_idx = next(bucket_idx);
}
if (dist_and_fingerprint != at(m_buckets, bucket_idx).m_dist_and_fingerprint) {
return 0;
}
do_erase(bucket_idx, handle_erased_value);
return 1;
}
template <class K, class M>
auto do_insert_or_assign(K&& key, M&& mapped) -> std::pair<iterator, bool> {
auto it_isinserted = try_emplace(std::forward<K>(key), std::forward<M>(mapped));
if (!it_isinserted.second) {
it_isinserted.first->second = std::forward<M>(mapped);
}
return it_isinserted;
}
template <typename... Args>
auto do_place_element(dist_and_fingerprint_type dist_and_fingerprint, value_idx_type bucket_idx, Args&&... args)
-> std::pair<iterator, bool> {
// emplace the new value. If that throws an exception, no harm done; index is still in a valid state
m_values.emplace_back(std::forward<Args>(args)...);
auto value_idx = static_cast<value_idx_type>(m_values.size() - 1);
if (ANKERL_UNORDERED_DENSE_UNLIKELY(is_full())) {
increase_size();
} else {
place_and_shift_up({dist_and_fingerprint, value_idx}, bucket_idx);
}
// place element and shift up until we find an empty spot
return {begin() + static_cast<difference_type>(value_idx), true};
}
template <typename K, typename... Args>
auto do_try_emplace(K&& key, Args&&... args) -> std::pair<iterator, bool> {
auto hash = mixed_hash(key);
auto dist_and_fingerprint = dist_and_fingerprint_from_hash(hash);
auto bucket_idx = bucket_idx_from_hash(hash);
while (true) {
auto* bucket = &at(m_buckets, bucket_idx);
if (dist_and_fingerprint == bucket->m_dist_and_fingerprint) {
if (m_equal(key, get_key(m_values[bucket->m_value_idx]))) {
return {begin() + static_cast<difference_type>(bucket->m_value_idx), false};
}
} else if (dist_and_fingerprint > bucket->m_dist_and_fingerprint) {
return do_place_element(dist_and_fingerprint,
bucket_idx,
std::piecewise_construct,
std::forward_as_tuple(std::forward<K>(key)),
std::forward_as_tuple(std::forward<Args>(args)...));
}
dist_and_fingerprint = dist_inc(dist_and_fingerprint);
bucket_idx = next(bucket_idx);
}
}
template <typename K>
auto do_find(K const& key) -> iterator {
if (ANKERL_UNORDERED_DENSE_UNLIKELY(empty())) {
return end();
}
auto mh = mixed_hash(key);
auto dist_and_fingerprint = dist_and_fingerprint_from_hash(mh);
auto bucket_idx = bucket_idx_from_hash(mh);
auto* bucket = &at(m_buckets, bucket_idx);
// unrolled loop. *Always* check a few directly, then enter the loop. This is faster.
if (dist_and_fingerprint == bucket->m_dist_and_fingerprint && m_equal(key, get_key(m_values[bucket->m_value_idx]))) {
return begin() + static_cast<difference_type>(bucket->m_value_idx);
}
dist_and_fingerprint = dist_inc(dist_and_fingerprint);
bucket_idx = next(bucket_idx);
bucket = &at(m_buckets, bucket_idx);
if (dist_and_fingerprint == bucket->m_dist_and_fingerprint && m_equal(key, get_key(m_values[bucket->m_value_idx]))) {
return begin() + static_cast<difference_type>(bucket->m_value_idx);
}
dist_and_fingerprint = dist_inc(dist_and_fingerprint);
bucket_idx = next(bucket_idx);
bucket = &at(m_buckets, bucket_idx);
while (true) {
if (dist_and_fingerprint == bucket->m_dist_and_fingerprint) {
if (m_equal(key, get_key(m_values[bucket->m_value_idx]))) {
return begin() + static_cast<difference_type>(bucket->m_value_idx);
}
} else if (dist_and_fingerprint > bucket->m_dist_and_fingerprint) {
return end();
}
dist_and_fingerprint = dist_inc(dist_and_fingerprint);
bucket_idx = next(bucket_idx);
bucket = &at(m_buckets, bucket_idx);
}
}
template <typename K>
auto do_find(K const& key) const -> const_iterator {
return const_cast<table*>(this)->do_find(key); // NOLINT(cppcoreguidelines-pro-type-const-cast)
}
template <typename K, typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto do_at(K const& key) -> Q& {
if (auto it = find(key); ANKERL_UNORDERED_DENSE_LIKELY(end() != it)) {
return it->second;
}
on_error_key_not_found();
}
template <typename K, typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto do_at(K const& key) const -> Q const& {
return const_cast<table*>(this)->at(key); // NOLINT(cppcoreguidelines-pro-type-const-cast)
}
public:
explicit table(size_t bucket_count,
Hash const& hash = Hash(),
KeyEqual const& equal = KeyEqual(),
allocator_type const& alloc_or_container = allocator_type())
: m_values(alloc_or_container)
, m_hash(hash)
, m_equal(equal) {
if (0 != bucket_count) {
reserve(bucket_count);
} else {
allocate_buckets_from_shift();
clear_buckets();
}
}
table()
: table(0) {}
table(size_t bucket_count, allocator_type const& alloc)
: table(bucket_count, Hash(), KeyEqual(), alloc) {}
table(size_t bucket_count, Hash const& hash, allocator_type const& alloc)
: table(bucket_count, hash, KeyEqual(), alloc) {}
explicit table(allocator_type const& alloc)
: table(0, Hash(), KeyEqual(), alloc) {}
template <class InputIt>
table(InputIt first,
InputIt last,
size_type bucket_count = 0,
Hash const& hash = Hash(),
KeyEqual const& equal = KeyEqual(),
allocator_type const& alloc = allocator_type())
: table(bucket_count, hash, equal, alloc) {
insert(first, last);
}
template <class InputIt>
table(InputIt first, InputIt last, size_type bucket_count, allocator_type const& alloc)
: table(first, last, bucket_count, Hash(), KeyEqual(), alloc) {}
template <class InputIt>
table(InputIt first, InputIt last, size_type bucket_count, Hash const& hash, allocator_type const& alloc)
: table(first, last, bucket_count, hash, KeyEqual(), alloc) {}
table(table const& other)
: table(other, other.m_values.get_allocator()) {}
table(table const& other, allocator_type const& alloc)
: m_values(other.m_values, alloc)
, m_max_load_factor(other.m_max_load_factor)
, m_hash(other.m_hash)
, m_equal(other.m_equal) {
copy_buckets(other);
}
table(table&& other) noexcept
: table(std::move(other), other.m_values.get_allocator()) {}
table(table&& other, allocator_type const& alloc) noexcept
: m_values(alloc) {
*this = std::move(other);
}
table(std::initializer_list<value_type> ilist,
size_t bucket_count = 0,
Hash const& hash = Hash(),
KeyEqual const& equal = KeyEqual(),
allocator_type const& alloc = allocator_type())
: table(bucket_count, hash, equal, alloc) {
insert(ilist);
}
table(std::initializer_list<value_type> ilist, size_type bucket_count, allocator_type const& alloc)
: table(ilist, bucket_count, Hash(), KeyEqual(), alloc) {}
table(std::initializer_list<value_type> init, size_type bucket_count, Hash const& hash, allocator_type const& alloc)
: table(init, bucket_count, hash, KeyEqual(), alloc) {}
~table() {
if (nullptr != m_buckets) {
auto ba = bucket_alloc(m_values.get_allocator());
bucket_alloc_traits::deallocate(ba, m_buckets, bucket_count());
}
}
auto operator=(table const& other) -> table& {
if (&other != this) {
deallocate_buckets(); // deallocate before m_values is set (might have another allocator)
m_values = other.m_values;
m_max_load_factor = other.m_max_load_factor;
m_hash = other.m_hash;
m_equal = other.m_equal;
m_shifts = initial_shifts;
copy_buckets(other);
}
return *this;
}
auto operator=(table&& other) noexcept(noexcept(std::is_nothrow_move_assignable_v<value_container_type> &&
std::is_nothrow_move_assignable_v<Hash> &&
std::is_nothrow_move_assignable_v<KeyEqual>)) -> table& {
if (&other != this) {
deallocate_buckets(); // deallocate before m_values is set (might have another allocator)
m_values = std::move(other.m_values);
other.m_values.clear();
// we can only reuse m_buckets when both maps have the same allocator!
if (get_allocator() == other.get_allocator()) {
m_buckets = std::exchange(other.m_buckets, nullptr);
m_num_buckets = std::exchange(other.m_num_buckets, 0);
m_max_bucket_capacity = std::exchange(other.m_max_bucket_capacity, 0);
m_shifts = std::exchange(other.m_shifts, initial_shifts);
m_max_load_factor = std::exchange(other.m_max_load_factor, default_max_load_factor);
m_hash = std::exchange(other.m_hash, {});
m_equal = std::exchange(other.m_equal, {});
other.allocate_buckets_from_shift();
other.clear_buckets();
} else {
// set max_load_factor *before* copying the other's buckets, so we have the same
// behavior
m_max_load_factor = other.m_max_load_factor;
// copy_buckets sets m_buckets, m_num_buckets, m_max_bucket_capacity, m_shifts
copy_buckets(other);
// clear's the other's buckets so other is now already usable.
other.clear_buckets();
m_hash = other.m_hash;
m_equal = other.m_equal;
}
// map "other" is now already usable, it's empty.
}
return *this;
}
auto operator=(std::initializer_list<value_type> ilist) -> table& {
clear();
insert(ilist);
return *this;
}
auto get_allocator() const noexcept -> allocator_type {
return m_values.get_allocator();
}
// iterators //////////////////////////////////////////////////////////////
auto begin() noexcept -> iterator {
return m_values.begin();
}
auto begin() const noexcept -> const_iterator {
return m_values.begin();
}
auto cbegin() const noexcept -> const_iterator {
return m_values.cbegin();
}
auto end() noexcept -> iterator {
return m_values.end();
}
auto cend() const noexcept -> const_iterator {
return m_values.cend();
}
auto end() const noexcept -> const_iterator {
return m_values.end();
}
// capacity ///////////////////////////////////////////////////////////////
[[nodiscard]] auto empty() const noexcept -> bool {
return m_values.empty();
}
[[nodiscard]] auto size() const noexcept -> size_t {
return m_values.size();
}
[[nodiscard]] static constexpr auto max_size() noexcept -> size_t {
if constexpr ((std::numeric_limits<value_idx_type>::max)() == (std::numeric_limits<size_t>::max)()) {
return size_t{1} << (sizeof(value_idx_type) * 8 - 1);
} else {
return size_t{1} << (sizeof(value_idx_type) * 8);
}
}
// modifiers //////////////////////////////////////////////////////////////
void clear() {
m_values.clear();
clear_buckets();
}
auto insert(value_type const& value) -> std::pair<iterator, bool> {
return emplace(value);
}
auto insert(value_type&& value) -> std::pair<iterator, bool> {
return emplace(std::move(value));
}
template <class P, std::enable_if_t<std::is_constructible_v<value_type, P&&>, bool> = true>
auto insert(P&& value) -> std::pair<iterator, bool> {
return emplace(std::forward<P>(value));
}
auto insert(const_iterator /*hint*/, value_type const& value) -> iterator {
return insert(value).first;
}
auto insert(const_iterator /*hint*/, value_type&& value) -> iterator {
return insert(std::move(value)).first;
}
template <class P, std::enable_if_t<std::is_constructible_v<value_type, P&&>, bool> = true>
auto insert(const_iterator /*hint*/, P&& value) -> iterator {
return insert(std::forward<P>(value)).first;
}
template <class InputIt>
void insert(InputIt first, InputIt last) {
while (first != last) {
insert(*first);
++first;
}
}
void insert(std::initializer_list<value_type> ilist) {
insert(ilist.begin(), ilist.end());
}
// nonstandard API: *this is emptied.
// Also see "A Standard flat_map" https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p0429r9.pdf
auto extract() && -> value_container_type {
return std::move(m_values);
}
// nonstandard API:
// Discards the internally held container and replaces it with the one passed. Erases non-unique elements.
auto replace(value_container_type&& container) {
if (ANKERL_UNORDERED_DENSE_UNLIKELY(container.size() > max_size())) {
on_error_too_many_elements();
}
auto shifts = calc_shifts_for_size(container.size());
if (0 == m_num_buckets || shifts < m_shifts || container.get_allocator() != m_values.get_allocator()) {
m_shifts = shifts;
deallocate_buckets();
allocate_buckets_from_shift();
}
clear_buckets();
m_values = std::move(container);
// can't use clear_and_fill_buckets_from_values() because container elements might not be unique
auto value_idx = value_idx_type{};
// loop until we reach the end of the container. duplicated entries will be replaced with back().
while (value_idx != static_cast<value_idx_type>(m_values.size())) {
auto const& key = get_key(m_values[value_idx]);
auto hash = mixed_hash(key);
auto dist_and_fingerprint = dist_and_fingerprint_from_hash(hash);
auto bucket_idx = bucket_idx_from_hash(hash);
bool key_found = false;
while (true) {
auto const& bucket = at(m_buckets, bucket_idx);
if (dist_and_fingerprint > bucket.m_dist_and_fingerprint) {
break;
}
if (dist_and_fingerprint == bucket.m_dist_and_fingerprint &&
m_equal(key, get_key(m_values[bucket.m_value_idx]))) {
key_found = true;
break;
}
dist_and_fingerprint = dist_inc(dist_and_fingerprint);
bucket_idx = next(bucket_idx);
}
if (key_found) {
if (value_idx != static_cast<value_idx_type>(m_values.size() - 1)) {
m_values[value_idx] = std::move(m_values.back());
}
m_values.pop_back();
} else {
place_and_shift_up({dist_and_fingerprint, value_idx}, bucket_idx);
++value_idx;
}
}
}
template <class M, typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto insert_or_assign(Key const& key, M&& mapped) -> std::pair<iterator, bool> {
return do_insert_or_assign(key, std::forward<M>(mapped));
}
template <class M, typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto insert_or_assign(Key&& key, M&& mapped) -> std::pair<iterator, bool> {
return do_insert_or_assign(std::move(key), std::forward<M>(mapped));
}
template <typename K,
typename M,
typename Q = T,
typename H = Hash,
typename KE = KeyEqual,
std::enable_if_t<is_map_v<Q> && is_transparent_v<H, KE>, bool> = true>
auto insert_or_assign(K&& key, M&& mapped) -> std::pair<iterator, bool> {
return do_insert_or_assign(std::forward<K>(key), std::forward<M>(mapped));
}
template <class M, typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto insert_or_assign(const_iterator /*hint*/, Key const& key, M&& mapped) -> iterator {
return do_insert_or_assign(key, std::forward<M>(mapped)).first;
}
template <class M, typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto insert_or_assign(const_iterator /*hint*/, Key&& key, M&& mapped) -> iterator {
return do_insert_or_assign(std::move(key), std::forward<M>(mapped)).first;
}
template <typename K,
typename M,
typename Q = T,
typename H = Hash,
typename KE = KeyEqual,
std::enable_if_t<is_map_v<Q> && is_transparent_v<H, KE>, bool> = true>
auto insert_or_assign(const_iterator /*hint*/, K&& key, M&& mapped) -> iterator {
return do_insert_or_assign(std::forward<K>(key), std::forward<M>(mapped)).first;
}
// Single arguments for unordered_set can be used without having to construct the value_type
template <class K,
typename Q = T,
typename H = Hash,
typename KE = KeyEqual,
std::enable_if_t<!is_map_v<Q> && is_transparent_v<H, KE>, bool> = true>
auto emplace(K&& key) -> std::pair<iterator, bool> {
auto hash = mixed_hash(key);
auto dist_and_fingerprint = dist_and_fingerprint_from_hash(hash);
auto bucket_idx = bucket_idx_from_hash(hash);
while (dist_and_fingerprint <= at(m_buckets, bucket_idx).m_dist_and_fingerprint) {
if (dist_and_fingerprint == at(m_buckets, bucket_idx).m_dist_and_fingerprint &&
m_equal(key, m_values[at(m_buckets, bucket_idx).m_value_idx])) {
// found it, return without ever actually creating anything
return {begin() + static_cast<difference_type>(at(m_buckets, bucket_idx).m_value_idx), false};
}
dist_and_fingerprint = dist_inc(dist_and_fingerprint);
bucket_idx = next(bucket_idx);
}
// value is new, insert element first, so when exception happens we are in a valid state
return do_place_element(dist_and_fingerprint, bucket_idx, std::forward<K>(key));
}
template <class... Args>
auto emplace(Args&&... args) -> std::pair<iterator, bool> {
// we have to instantiate the value_type to be able to access the key.
// 1. emplace_back the object so it is constructed. 2. If the key is already there, pop it later in the loop.
auto& key = get_key(m_values.emplace_back(std::forward<Args>(args)...));
auto hash = mixed_hash(key);
auto dist_and_fingerprint = dist_and_fingerprint_from_hash(hash);
auto bucket_idx = bucket_idx_from_hash(hash);
while (dist_and_fingerprint <= at(m_buckets, bucket_idx).m_dist_and_fingerprint) {
if (dist_and_fingerprint == at(m_buckets, bucket_idx).m_dist_and_fingerprint &&
m_equal(key, get_key(m_values[at(m_buckets, bucket_idx).m_value_idx]))) {
m_values.pop_back(); // value was already there, so get rid of it
return {begin() + static_cast<difference_type>(at(m_buckets, bucket_idx).m_value_idx), false};
}
dist_and_fingerprint = dist_inc(dist_and_fingerprint);
bucket_idx = next(bucket_idx);
}
// value is new, place the bucket and shift up until we find an empty spot
auto value_idx = static_cast<value_idx_type>(m_values.size() - 1);
if (ANKERL_UNORDERED_DENSE_UNLIKELY(is_full())) {
// increase_size just rehashes all the data we have in m_values
increase_size();
} else {
// place element and shift up until we find an empty spot
place_and_shift_up({dist_and_fingerprint, value_idx}, bucket_idx);
}
return {begin() + static_cast<difference_type>(value_idx), true};
}
template <class... Args>
auto emplace_hint(const_iterator /*hint*/, Args&&... args) -> iterator {
return emplace(std::forward<Args>(args)...).first;
}
template <class... Args, typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto try_emplace(Key const& key, Args&&... args) -> std::pair<iterator, bool> {
return do_try_emplace(key, std::forward<Args>(args)...);
}
template <class... Args, typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto try_emplace(Key&& key, Args&&... args) -> std::pair<iterator, bool> {
return do_try_emplace(std::move(key), std::forward<Args>(args)...);
}
template <class... Args, typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto try_emplace(const_iterator /*hint*/, Key const& key, Args&&... args) -> iterator {
return do_try_emplace(key, std::forward<Args>(args)...).first;
}
template <class... Args, typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto try_emplace(const_iterator /*hint*/, Key&& key, Args&&... args) -> iterator {
return do_try_emplace(std::move(key), std::forward<Args>(args)...).first;
}
template <
typename K,
typename... Args,
typename Q = T,
typename H = Hash,
typename KE = KeyEqual,
std::enable_if_t<is_map_v<Q> && is_transparent_v<H, KE> && is_neither_convertible_v<K&&, iterator, const_iterator>,
bool> = true>
auto try_emplace(K&& key, Args&&... args) -> std::pair<iterator, bool> {
return do_try_emplace(std::forward<K>(key), std::forward<Args>(args)...);
}
template <
typename K,
typename... Args,
typename Q = T,
typename H = Hash,
typename KE = KeyEqual,
std::enable_if_t<is_map_v<Q> && is_transparent_v<H, KE> && is_neither_convertible_v<K&&, iterator, const_iterator>,
bool> = true>
auto try_emplace(const_iterator /*hint*/, K&& key, Args&&... args) -> iterator {
return do_try_emplace(std::forward<K>(key), std::forward<Args>(args)...).first;
}
auto erase(iterator it) -> iterator {
auto hash = mixed_hash(get_key(*it));
auto bucket_idx = bucket_idx_from_hash(hash);
auto const value_idx_to_remove = static_cast<value_idx_type>(it - cbegin());
while (at(m_buckets, bucket_idx).m_value_idx != value_idx_to_remove) {
bucket_idx = next(bucket_idx);
}
do_erase(bucket_idx, [](value_type&& /*unused*/) {
});
return begin() + static_cast<difference_type>(value_idx_to_remove);
}
auto extract(iterator it) -> value_type {
auto hash = mixed_hash(get_key(*it));
auto bucket_idx = bucket_idx_from_hash(hash);
auto const value_idx_to_remove = static_cast<value_idx_type>(it - cbegin());
while (at(m_buckets, bucket_idx).m_value_idx != value_idx_to_remove) {
bucket_idx = next(bucket_idx);
}
auto tmp = std::optional<value_type>{};
do_erase(bucket_idx, [&tmp](value_type&& val) {
tmp = std::move(val);
});
return std::move(tmp).value();
}
template <typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto erase(const_iterator it) -> iterator {
return erase(begin() + (it - cbegin()));
}
template <typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto extract(const_iterator it) -> value_type {
return extract(begin() + (it - cbegin()));
}
auto erase(const_iterator first, const_iterator last) -> iterator {
auto const idx_first = first - cbegin();
auto const idx_last = last - cbegin();
auto const first_to_last = std::distance(first, last);
auto const last_to_end = std::distance(last, cend());
// remove elements from left to right which moves elements from the end back
auto const mid = idx_first + (std::min)(first_to_last, last_to_end);
auto idx = idx_first;
while (idx != mid) {
erase(begin() + idx);
++idx;
}
// all elements from the right are moved, now remove the last element until all done
idx = idx_last;
while (idx != mid) {
--idx;
erase(begin() + idx);
}
return begin() + idx_first;
}
auto erase(Key const& key) -> size_t {
return do_erase_key(key, [](value_type&& /*unused*/) {
});
}
auto extract(Key const& key) -> std::optional<value_type> {
auto tmp = std::optional<value_type>{};
do_erase_key(key, [&tmp](value_type&& val) {
tmp = std::move(val);
});
return tmp;
}
template <class K, class H = Hash, class KE = KeyEqual, std::enable_if_t<is_transparent_v<H, KE>, bool> = true>
auto erase(K&& key) -> size_t {
return do_erase_key(std::forward<K>(key), [](value_type&& /*unused*/) {
});
}
template <class K, class H = Hash, class KE = KeyEqual, std::enable_if_t<is_transparent_v<H, KE>, bool> = true>
auto extract(K&& key) -> std::optional<value_type> {
auto tmp = std::optional<value_type>{};
do_erase_key(std::forward<K>(key), [&tmp](value_type&& val) {
tmp = std::move(val);
});
return tmp;
}
void swap(table& other) noexcept(noexcept(std::is_nothrow_swappable_v<value_container_type> &&
std::is_nothrow_swappable_v<Hash> && std::is_nothrow_swappable_v<KeyEqual>)) {
using std::swap;
swap(other, *this);
}
// lookup /////////////////////////////////////////////////////////////////
template <typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto at(key_type const& key) -> Q& {
return do_at(key);
}
template <typename K,
typename Q = T,
typename H = Hash,
typename KE = KeyEqual,
std::enable_if_t<is_map_v<Q> && is_transparent_v<H, KE>, bool> = true>
auto at(K const& key) -> Q& {
return do_at(key);
}
template <typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto at(key_type const& key) const -> Q const& {
return do_at(key);
}
template <typename K,
typename Q = T,
typename H = Hash,
typename KE = KeyEqual,
std::enable_if_t<is_map_v<Q> && is_transparent_v<H, KE>, bool> = true>
auto at(K const& key) const -> Q const& {
return do_at(key);
}
template <typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto operator[](Key const& key) -> Q& {
return try_emplace(key).first->second;
}
template <typename Q = T, std::enable_if_t<is_map_v<Q>, bool> = true>
auto operator[](Key&& key) -> Q& {
return try_emplace(std::move(key)).first->second;
}
template <typename K,
typename Q = T,
typename H = Hash,
typename KE = KeyEqual,
std::enable_if_t<is_map_v<Q> && is_transparent_v<H, KE>, bool> = true>
auto operator[](K&& key) -> Q& {
return try_emplace(std::forward<K>(key)).first->second;
}
auto count(Key const& key) const -> size_t {
return find(key) == end() ? 0 : 1;
}
template <class K, class H = Hash, class KE = KeyEqual, std::enable_if_t<is_transparent_v<H, KE>, bool> = true>
auto count(K const& key) const -> size_t {
return find(key) == end() ? 0 : 1;
}
auto find(Key const& key) -> iterator {
return do_find(key);
}
auto find(Key const& key) const -> const_iterator {
return do_find(key);
}
template <class K, class H = Hash, class KE = KeyEqual, std::enable_if_t<is_transparent_v<H, KE>, bool> = true>
auto find(K const& key) -> iterator {
return do_find(key);
}
template <class K, class H = Hash, class KE = KeyEqual, std::enable_if_t<is_transparent_v<H, KE>, bool> = true>
auto find(K const& key) const -> const_iterator {
return do_find(key);
}
auto contains(Key const& key) const -> bool {
return find(key) != end();
}
template <class K, class H = Hash, class KE = KeyEqual, std::enable_if_t<is_transparent_v<H, KE>, bool> = true>
auto contains(K const& key) const -> bool {
return find(key) != end();
}
auto equal_range(Key const& key) -> std::pair<iterator, iterator> {
auto it = do_find(key);
return {it, it == end() ? end() : it + 1};
}
auto equal_range(const Key& key) const -> std::pair<const_iterator, const_iterator> {
auto it = do_find(key);
return {it, it == end() ? end() : it + 1};
}
template <class K, class H = Hash, class KE = KeyEqual, std::enable_if_t<is_transparent_v<H, KE>, bool> = true>
auto equal_range(K const& key) -> std::pair<iterator, iterator> {
auto it = do_find(key);
return {it, it == end() ? end() : it + 1};
}
template <class K, class H = Hash, class KE = KeyEqual, std::enable_if_t<is_transparent_v<H, KE>, bool> = true>
auto equal_range(K const& key) const -> std::pair<const_iterator, const_iterator> {
auto it = do_find(key);
return {it, it == end() ? end() : it + 1};
}
// bucket interface ///////////////////////////////////////////////////////
auto bucket_count() const noexcept -> size_t { // NOLINT(modernize-use-nodiscard)
return m_num_buckets;
}
static constexpr auto max_bucket_count() noexcept -> size_t { // NOLINT(modernize-use-nodiscard)
return max_size();
}
// hash policy ////////////////////////////////////////////////////////////
[[nodiscard]] auto load_factor() const -> float {
return bucket_count() ? static_cast<float>(size()) / static_cast<float>(bucket_count()) : 0.0F;
}
[[nodiscard]] auto max_load_factor() const -> float {
return m_max_load_factor;
}
void max_load_factor(float ml) {
m_max_load_factor = ml;
if (m_num_buckets != max_bucket_count()) {
m_max_bucket_capacity = static_cast<value_idx_type>(static_cast<float>(bucket_count()) * max_load_factor());
}
}
void rehash(size_t count) {
count = (std::min)(count, max_size());
auto shifts = calc_shifts_for_size((std::max)(count, size()));
if (shifts != m_shifts) {
m_shifts = shifts;
deallocate_buckets();
m_values.shrink_to_fit();
allocate_buckets_from_shift();
clear_and_fill_buckets_from_values();
}
}
void reserve(size_t capa) {
capa = (std::min)(capa, max_size());
if constexpr (has_reserve<value_container_type>) {
// std::deque doesn't have reserve(). Make sure we only call when available
m_values.reserve(capa);
}
auto shifts = calc_shifts_for_size((std::max)(capa, size()));
if (0 == m_num_buckets || shifts < m_shifts) {
m_shifts = shifts;
deallocate_buckets();
allocate_buckets_from_shift();
clear_and_fill_buckets_from_values();
}
}
// observers //////////////////////////////////////////////////////////////
auto hash_function() const -> hasher {
return m_hash;
}
auto key_eq() const -> key_equal {
return m_equal;
}
// nonstandard API: expose the underlying values container
[[nodiscard]] auto values() const noexcept -> value_container_type const& {
return m_values;
}
// non-member functions ///////////////////////////////////////////////////
friend auto operator==(table const& a, table const& b) -> bool {
if (&a == &b) {
return true;
}
if (a.size() != b.size()) {
return false;
}
for (auto const& b_entry : b) {
auto it = a.find(get_key(b_entry));
if constexpr (is_map_v<T>) {
// map: check that key is here, then also check that value is the same
if (a.end() == it || !(b_entry.second == it->second)) {
return false;
}
} else {
// set: only check that the key is here
if (a.end() == it) {
return false;
}
}
}
return true;
}
friend auto operator!=(table const& a, table const& b) -> bool {
return !(a == b);
}
};
} /* namespace detail */
ANKERL_UNORDERED_DENSE_EXPORT template <class Key,
class T,
class Hash = hash<Key>,
class KeyEqual = std::equal_to<Key>,
class AllocatorOrContainer = std::allocator<std::pair<Key, T>>,
class Bucket = bucket_type::standard>
using map = detail::table<Key, T, Hash, KeyEqual, AllocatorOrContainer, Bucket, false>;
ANKERL_UNORDERED_DENSE_EXPORT template <class Key,
class T,
class Hash = hash<Key>,
class KeyEqual = std::equal_to<Key>,
class AllocatorOrContainer = std::allocator<std::pair<Key, T>>,
class Bucket = bucket_type::standard>
using segmented_map = detail::table<Key, T, Hash, KeyEqual, AllocatorOrContainer, Bucket, true>;
ANKERL_UNORDERED_DENSE_EXPORT template <class Key,
class Hash = hash<Key>,
class KeyEqual = std::equal_to<Key>,
class AllocatorOrContainer = std::allocator<Key>,
class Bucket = bucket_type::standard>
using set = detail::table<Key, void, Hash, KeyEqual, AllocatorOrContainer, Bucket, false>;
ANKERL_UNORDERED_DENSE_EXPORT template <class Key,
class Hash = hash<Key>,
class KeyEqual = std::equal_to<Key>,
class AllocatorOrContainer = std::allocator<Key>,
class Bucket = bucket_type::standard>
using segmented_set = detail::table<Key, void, Hash, KeyEqual, AllocatorOrContainer, Bucket, true>;
# if defined(ANKERL_UNORDERED_DENSE_PMR)
namespace pmr {
ANKERL_UNORDERED_DENSE_EXPORT template <class Key,
class T,
class Hash = hash<Key>,
class KeyEqual = std::equal_to<Key>,
class Bucket = bucket_type::standard>
using map =
detail::table<Key, T, Hash, KeyEqual, ANKERL_UNORDERED_DENSE_PMR::polymorphic_allocator<std::pair<Key, T>>, Bucket, false>;
ANKERL_UNORDERED_DENSE_EXPORT template <class Key,
class T,
class Hash = hash<Key>,
class KeyEqual = std::equal_to<Key>,
class Bucket = bucket_type::standard>
using segmented_map =
detail::table<Key, T, Hash, KeyEqual, ANKERL_UNORDERED_DENSE_PMR::polymorphic_allocator<std::pair<Key, T>>, Bucket, true>;
ANKERL_UNORDERED_DENSE_EXPORT template <class Key,
class Hash = hash<Key>,
class KeyEqual = std::equal_to<Key>,
class Bucket = bucket_type::standard>
using set = detail::table<Key, void, Hash, KeyEqual, ANKERL_UNORDERED_DENSE_PMR::polymorphic_allocator<Key>, Bucket, false>;
ANKERL_UNORDERED_DENSE_EXPORT template <class Key,
class Hash = hash<Key>,
class KeyEqual = std::equal_to<Key>,
class Bucket = bucket_type::standard>
using segmented_set =
detail::table<Key, void, Hash, KeyEqual, ANKERL_UNORDERED_DENSE_PMR::polymorphic_allocator<Key>, Bucket, true>;
} /* namespace pmr */
# endif
// deduction guides ///////////////////////////////////////////////////////////
// deduction guides for alias templates are only possible since C++20
// see https://en.cppreference.com/w/cpp/language/class_template_argument_deduction
} /* namespace ANKERL_UNORDERED_DENSE_NAMESPACE */
} /* namespace ankerl::unordered_dense */
// std extensions /////////////////////////////////////////////////////////////
namespace std { // NOLINT(cert-dcl58-cpp)
ANKERL_UNORDERED_DENSE_EXPORT template <class Key,
class T,
class Hash,
class KeyEqual,
class AllocatorOrContainer,
class Bucket,
class Pred,
bool IsSegmented>
// NOLINTNEXTLINE(cert-dcl58-cpp)
auto erase_if(ankerl::unordered_dense::detail::table<Key, T, Hash, KeyEqual, AllocatorOrContainer, Bucket, IsSegmented>& map,
Pred pred) -> size_t {
using map_t = ankerl::unordered_dense::detail::table<Key, T, Hash, KeyEqual, AllocatorOrContainer, Bucket, IsSegmented>;
// going back to front because erase() invalidates the end iterator
auto const old_size = map.size();
auto idx = old_size;
while (idx) {
--idx;
auto it = map.begin() + static_cast<typename map_t::difference_type>(idx);
if (pred(*it)) {
map.erase(it);
}
}
return old_size - map.size();
}
} /* namespace std */
#endif
#endif