wip

parallel_hashmap/phmap_base.h

@@ -0,0 +1,511 @@
+#if !defined(phmap_base_h_guard_)
+#define phmap_base_h_guard_
+
+// ---------------------------------------------------------------------------
+// Copyright (c) 2019, Gregory Popovitch - greg7mdp@gmail.com
+//
+// 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
+//
+//      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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Includes work from abseil-cpp (https://github.com/abseil/abseil-cpp)
+// with modifications.
+// 
+// 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
+//
+//      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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ---------------------------------------------------------------------------
+
+#include <stddef.h>
+#include <functional>
+#include <type_traits>
+
+#include "phmap_config.h"
+
+namespace phmap {
+
+namespace type_traits_internal {
+
+template <typename... Ts>
+struct VoidTImpl {
+  using type = void;
+};
+
+// This trick to retrieve a default alignment is necessary for our
+// implementation of aligned_storage_t to be consistent with any implementation
+// of std::aligned_storage.
+// ---------------------------------------------------------------------------
+template <size_t Len, typename T = std::aligned_storage<Len>>
+struct default_alignment_of_aligned_storage;
+
+template <size_t Len, size_t Align>
+struct default_alignment_of_aligned_storage<Len,
+                                            std::aligned_storage<Len, Align>> {
+  static constexpr size_t value = Align;
+};
+
+// NOTE: The `is_detected` family of templates here differ from the library
+// fundamentals specification in that for library fundamentals, `Op<Args...>` is
+// evaluated as soon as the type `is_detected<Op, Args...>` undergoes
+// substitution, regardless of whether or not the `::value` is accessed. That
+// is inconsistent with all other standard traits and prevents lazy evaluation
+// in larger contexts (such as if the `is_detected` check is a trailing argument
+// of a `conjunction`. This implementation opts to instead be lazy in the same
+// way that the standard traits are (this "defect" of the detection idiom
+// specifications has been reported).
+// ---------------------------------------------------------------------------
+
+template <class Enabler, template <class...> class Op, class... Args>
+struct is_detected_impl {
+  using type = std::false_type;
+};
+
+template <template <class...> class Op, class... Args>
+struct is_detected_impl<typename VoidTImpl<Op<Args...>>::type, Op, Args...> {
+  using type = std::true_type;
+};
+
+template <template <class...> class Op, class... Args>
+struct is_detected : is_detected_impl<void, Op, Args...>::type {};
+
+template <class Enabler, class To, template <class...> class Op, class... Args>
+struct is_detected_convertible_impl {
+  using type = std::false_type;
+};
+
+template <class To, template <class...> class Op, class... Args>
+struct is_detected_convertible_impl<
+    typename std::enable_if<std::is_convertible<Op<Args...>, To>::value>::type,
+    To, Op, Args...> {
+  using type = std::true_type;
+};
+
+template <class To, template <class...> class Op, class... Args>
+struct is_detected_convertible
+    : is_detected_convertible_impl<void, To, Op, Args...>::type {};
+
+template <typename T>
+using IsCopyAssignableImpl =
+    decltype(std::declval<T&>() = std::declval<const T&>());
+
+template <typename T>
+using IsMoveAssignableImpl = decltype(std::declval<T&>() = std::declval<T&&>());
+
+}  // namespace type_traits_internal
+
+template <typename T>
+struct is_copy_assignable : type_traits_internal::is_detected<
+                                type_traits_internal::IsCopyAssignableImpl, T> {
+};
+
+template <typename T>
+struct is_move_assignable : type_traits_internal::is_detected<
+                                type_traits_internal::IsMoveAssignableImpl, T> {
+};
+
+// ---------------------------------------------------------------------------
+// void_t()
+//
+// Ignores the type of any its arguments and returns `void`. In general, this
+// metafunction allows you to create a general case that maps to `void` while
+// allowing specializations that map to specific types.
+//
+// This metafunction is designed to be a drop-in replacement for the C++17
+// `std::void_t` metafunction.
+//
+// NOTE: `phmap::void_t` does not use the standard-specified implementation so
+// that it can remain compatible with gcc < 5.1. This can introduce slightly
+// different behavior, such as when ordering partial specializations.
+// ---------------------------------------------------------------------------
+template <typename... Ts>
+using void_t = typename type_traits_internal::VoidTImpl<Ts...>::type;
+
+// ---------------------------------------------------------------------------
+// conjunction
+//
+// Performs a compile-time logical AND operation on the passed types (which
+// must have  `::value` members convertible to `bool`. Short-circuits if it
+// encounters any `false` members (and does not compare the `::value` members
+// of any remaining arguments).
+//
+// This metafunction is designed to be a drop-in replacement for the C++17
+// `std::conjunction` metafunction.
+// ---------------------------------------------------------------------------
+template <typename... Ts>
+struct conjunction;
+
+template <typename T, typename... Ts>
+struct conjunction<T, Ts...>
+    : std::conditional<T::value, conjunction<Ts...>, T>::type {};
+
+template <typename T>
+struct conjunction<T> : T {};
+
+template <>
+struct conjunction<> : std::true_type {};
+
+// ---------------------------------------------------------------------------
+// disjunction
+//
+// Performs a compile-time logical OR operation on the passed types (which
+// must have  `::value` members convertible to `bool`. Short-circuits if it
+// encounters any `true` members (and does not compare the `::value` members
+// of any remaining arguments).
+//
+// This metafunction is designed to be a drop-in replacement for the C++17
+// `std::disjunction` metafunction.
+// ---------------------------------------------------------------------------
+template <typename... Ts>
+struct disjunction;
+
+template <typename T, typename... Ts>
+struct disjunction<T, Ts...> :
+      std::conditional<T::value, T, disjunction<Ts...>>::type {};
+
+template <typename T>
+struct disjunction<T> : T {};
+
+template <>
+struct disjunction<> : std::false_type {};
+
+// ---------------------------------------------------------------------------
+// negation
+//
+// Performs a compile-time logical NOT operation on the passed type (which
+// must have  `::value` members convertible to `bool`.
+//
+// This metafunction is designed to be a drop-in replacement for the C++17
+// `std::negation` metafunction.
+// ---------------------------------------------------------------------------
+template <typename T>
+struct negation : std::integral_constant<bool, !T::value> {};
+
+// ---------------------------------------------------------------------------
+// is_trivially_destructible()
+//
+// Determines whether the passed type `T` is trivially destructable.
+//
+// This metafunction is designed to be a drop-in replacement for the C++11
+// `std::is_trivially_destructible()` metafunction for platforms that have
+// incomplete C++11 support (such as libstdc++ 4.x). On any platforms that do
+// fully support C++11, we check whether this yields the same result as the std
+// implementation.
+//
+// NOTE: the extensions (__has_trivial_xxx) are implemented in gcc (version >=
+// 4.3) and clang. Since we are supporting libstdc++ > 4.7, they should always
+// be present. These  extensions are documented at
+// https://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html#Type-Traits.
+// ---------------------------------------------------------------------------
+template <typename T>
+struct is_trivially_destructible
+    : std::integral_constant<bool, __has_trivial_destructor(T) &&
+                                   std::is_destructible<T>::value> 
+{
+#ifdef PHMAP_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE
+private:
+    static constexpr bool compliant = std::is_trivially_destructible<T>::value ==
+        is_trivially_destructible::value;
+    static_assert(compliant || std::is_trivially_destructible<T>::value,
+                  "Not compliant with std::is_trivially_destructible; "
+                  "Standard: false, Implementation: true");
+    static_assert(compliant || !std::is_trivially_destructible<T>::value,
+                  "Not compliant with std::is_trivially_destructible; "
+                  "Standard: true, Implementation: false");
+#endif 
+};
+
+// ---------------------------------------------------------------------------
+// is_trivially_default_constructible()
+//
+// Determines whether the passed type `T` is trivially default constructible.
+//
+// This metafunction is designed to be a drop-in replacement for the C++11
+// `std::is_trivially_default_constructible()` metafunction for platforms that
+// have incomplete C++11 support (such as libstdc++ 4.x). On any platforms that
+// do fully support C++11, we check whether this yields the same result as the
+// std implementation.
+//
+// NOTE: according to the C++ standard, Section: 20.15.4.3 [meta.unary.prop]
+// "The predicate condition for a template specialization is_constructible<T,
+// Args...> shall be satisfied if and only if the following variable
+// definition would be well-formed for some invented variable t:
+//
+// T t(declval<Args>()...);
+//
+// is_trivially_constructible<T, Args...> additionally requires that the
+// variable definition does not call any operation that is not trivial.
+// For the purposes of this check, the call to std::declval is considered
+// trivial."
+//
+// Notes from https://en.cppreference.com/w/cpp/types/is_constructible:
+// In many implementations, is_nothrow_constructible also checks if the
+// destructor throws because it is effectively noexcept(T(arg)). Same
+// applies to is_trivially_constructible, which, in these implementations, also
+// requires that the destructor is trivial.
+// GCC bug 51452: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51452
+// LWG issue 2116: http://cplusplus.github.io/LWG/lwg-active.html#2116.
+//
+// "T obj();" need to be well-formed and not call any nontrivial operation.
+// Nontrivially destructible types will cause the expression to be nontrivial.
+// ---------------------------------------------------------------------------
+template <typename T>
+struct is_trivially_default_constructible
+    : std::integral_constant<bool, __has_trivial_constructor(T) &&
+                                   std::is_default_constructible<T>::value &&
+                                   is_trivially_destructible<T>::value> 
+{
+#ifdef PHMAP_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE
+private:
+    static constexpr bool compliant =
+        std::is_trivially_default_constructible<T>::value ==
+        is_trivially_default_constructible::value;
+    static_assert(compliant || std::is_trivially_default_constructible<T>::value,
+                  "Not compliant with std::is_trivially_default_constructible; "
+                  "Standard: false, Implementation: true");
+    static_assert(compliant || !std::is_trivially_default_constructible<T>::value,
+                  "Not compliant with std::is_trivially_default_constructible; "
+                  "Standard: true, Implementation: false");
+#endif
+};
+
+// ---------------------------------------------------------------------------
+// is_trivially_copy_constructible()
+//
+// Determines whether the passed type `T` is trivially copy constructible.
+//
+// This metafunction is designed to be a drop-in replacement for the C++11
+// `std::is_trivially_copy_constructible()` metafunction for platforms that have
+// incomplete C++11 support (such as libstdc++ 4.x). On any platforms that do
+// fully support C++11, we check whether this yields the same result as the std
+// implementation.
+//
+// NOTE: `T obj(declval<const T&>());` needs to be well-formed and not call any
+// nontrivial operation.  Nontrivially destructible types will cause the
+// expression to be nontrivial.
+// ---------------------------------------------------------------------------
+template <typename T>
+struct is_trivially_copy_constructible
+    : std::integral_constant<bool, __has_trivial_copy(T) &&
+                                   std::is_copy_constructible<T>::value &&
+                                   is_trivially_destructible<T>::value> 
+{
+#ifdef PHMAP_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE
+private:
+    static constexpr bool compliant =
+        std::is_trivially_copy_constructible<T>::value ==
+        is_trivially_copy_constructible::value;
+    static_assert(compliant || std::is_trivially_copy_constructible<T>::value,
+                  "Not compliant with std::is_trivially_copy_constructible; "
+                  "Standard: false, Implementation: true");
+    static_assert(compliant || !std::is_trivially_copy_constructible<T>::value,
+                  "Not compliant with std::is_trivially_copy_constructible; "
+                  "Standard: true, Implementation: false");
+#endif
+};
+
+// ---------------------------------------------------------------------------
+// is_trivially_copy_assignable()
+//
+// Determines whether the passed type `T` is trivially copy assignable.
+//
+// This metafunction is designed to be a drop-in replacement for the C++11
+// `std::is_trivially_copy_assignable()` metafunction for platforms that have
+// incomplete C++11 support (such as libstdc++ 4.x). On any platforms that do
+// fully support C++11, we check whether this yields the same result as the std
+// implementation.
+//
+// NOTE: `is_assignable<T, U>::value` is `true` if the expression
+// `declval<T>() = declval<U>()` is well-formed when treated as an unevaluated
+// operand. `is_trivially_assignable<T, U>` requires the assignment to call no
+// operation that is not trivial. `is_trivially_copy_assignable<T>` is simply
+// `is_trivially_assignable<T&, const T&>`.
+// ---------------------------------------------------------------------------
+template <typename T>
+struct is_trivially_copy_assignable
+    : std::integral_constant<
+          bool, __has_trivial_assign(typename std::remove_reference<T>::type) &&
+                    phmap::is_copy_assignable<T>::value> 
+{
+#ifdef PHMAP_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE
+private:
+    static constexpr bool compliant =
+        std::is_trivially_copy_assignable<T>::value ==
+        is_trivially_copy_assignable::value;
+    static_assert(compliant || std::is_trivially_copy_assignable<T>::value,
+                  "Not compliant with std::is_trivially_copy_assignable; "
+                  "Standard: false, Implementation: true");
+    static_assert(compliant || !std::is_trivially_copy_assignable<T>::value,
+                  "Not compliant with std::is_trivially_copy_assignable; "
+                  "Standard: true, Implementation: false");
+#endif
+};
+
+// -----------------------------------------------------------------------------
+// C++14 "_t" trait aliases
+// -----------------------------------------------------------------------------
+
+template <typename T>
+using remove_cv_t = typename std::remove_cv<T>::type;
+
+template <typename T>
+using remove_const_t = typename std::remove_const<T>::type;
+
+template <typename T>
+using remove_volatile_t = typename std::remove_volatile<T>::type;
+
+template <typename T>
+using add_cv_t = typename std::add_cv<T>::type;
+
+template <typename T>
+using add_const_t = typename std::add_const<T>::type;
+
+template <typename T>
+using add_volatile_t = typename std::add_volatile<T>::type;
+
+template <typename T>
+using remove_reference_t = typename std::remove_reference<T>::type;
+
+template <typename T>
+using add_lvalue_reference_t = typename std::add_lvalue_reference<T>::type;
+
+template <typename T>
+using add_rvalue_reference_t = typename std::add_rvalue_reference<T>::type;
+
+template <typename T>
+using remove_pointer_t = typename std::remove_pointer<T>::type;
+
+template <typename T>
+using add_pointer_t = typename std::add_pointer<T>::type;
+
+template <typename T>
+using make_signed_t = typename std::make_signed<T>::type;
+
+template <typename T>
+using make_unsigned_t = typename std::make_unsigned<T>::type;
+
+template <typename T>
+using remove_extent_t = typename std::remove_extent<T>::type;
+
+template <typename T>
+using remove_all_extents_t = typename std::remove_all_extents<T>::type;
+
+template <size_t Len, size_t Align = type_traits_internal::
+                          default_alignment_of_aligned_storage<Len>::value>
+using aligned_storage_t = typename std::aligned_storage<Len, Align>::type;
+
+template <typename T>
+using decay_t = typename std::decay<T>::type;
+
+template <bool B, typename T = void>
+using enable_if_t = typename std::enable_if<B, T>::type;
+
+template <bool B, typename T, typename F>
+using conditional_t = typename std::conditional<B, T, F>::type;
+
+template <typename... T>
+using common_type_t = typename std::common_type<T...>::type;
+
+template <typename T>
+using underlying_type_t = typename std::underlying_type<T>::type;
+
+template <typename T>
+using result_of_t = typename std::result_of<T>::type;
+
+namespace type_traits_internal {
+
+// ----------------------------------------------------------------------
+// In MSVC we can't probe std::hash or stdext::hash because it triggers a
+// static_assert instead of failing substitution. Libc++ prior to 4.0
+// also used a static_assert.
+// ----------------------------------------------------------------------
+#if defined(_MSC_VER) || (defined(_LIBCPP_VERSION) && \
+                          _LIBCPP_VERSION < 4000 && _LIBCPP_STD_VER > 11)
+    #define PHMAP_META_INTERNAL_STD_HASH_SFINAE_FRIENDLY_ 0
+#else
+    #define PHMAP_META_INTERNAL_STD_HASH_SFINAE_FRIENDLY_ 1
+#endif
+
+#if !PHMAP_META_INTERNAL_STD_HASH_SFINAE_FRIENDLY_
+    template <typename Key, typename = size_t>
+    struct IsHashable : std::true_type {};
+#else   // PHMAP_META_INTERNAL_STD_HASH_SFINAE_FRIENDLY_
+    template <typename Key, typename = void>
+    struct IsHashable : std::false_type {};
+
+    template <typename Key>
+    struct IsHashable<
+        Key,
+        phmap::enable_if_t<std::is_convertible<
+            decltype(std::declval<std::hash<Key>&>()(std::declval<Key const&>())),
+            std::size_t>::value>> : std::true_type {};
+#endif
+
+struct AssertHashEnabledHelper 
+{
+private:
+    static void Sink(...) {}
+    struct NAT {};
+
+    template <class Key>
+    static auto GetReturnType(int)
+        -> decltype(std::declval<std::hash<Key>>()(std::declval<Key const&>()));
+    template <class Key>
+    static NAT GetReturnType(...);
+
+    template <class Key>
+    static std::nullptr_t DoIt() {
+        static_assert(IsHashable<Key>::value,
+                      "std::hash<Key> does not provide a call operator");
+        static_assert(
+            std::is_default_constructible<std::hash<Key>>::value,
+            "std::hash<Key> must be default constructible when it is enabled");
+        static_assert(
+            std::is_copy_constructible<std::hash<Key>>::value,
+            "std::hash<Key> must be copy constructible when it is enabled");
+        static_assert(phmap::is_copy_assignable<std::hash<Key>>::value,
+                      "std::hash<Key> must be copy assignable when it is enabled");
+        // is_destructible is unchecked as it's implied by each of the
+        // is_constructible checks.
+        using ReturnType = decltype(GetReturnType<Key>(0));
+        static_assert(std::is_same<ReturnType, NAT>::value ||
+                      std::is_same<ReturnType, size_t>::value,
+                      "std::hash<Key> must return size_t");
+        return nullptr;
+    }
+
+    template <class... Ts>
+    friend void AssertHashEnabled();
+};
+
+template <class... Ts>
+inline void AssertHashEnabled() 
+{
+    using Helper = AssertHashEnabledHelper;
+    Helper::Sink(Helper::DoIt<Ts>()...);
+}
+
+}  // namespace type_traits_internal
+
+}  // namespace phmap
+
+
+
+#endif // phmap_base_h_guard_

parallel_hashmap/phmap_bits.h

@@ -0,0 +1,358 @@
+#if !defined(phmap_bits_h_guard_)
+#define phmap_bits_h_guard_
+
+// ---------------------------------------------------------------------------
+// Copyright (c) 2019, Gregory Popovitch - greg7mdp@gmail.com
+//
+// 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
+//
+//      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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Includes work from abseil-cpp (https://github.com/abseil/abseil-cpp)
+// with modifications.
+// 
+// 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
+//
+//      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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ---------------------------------------------------------------------------
+
+// The following guarantees declaration of the byte swap functions
+#ifdef _MSC_VER
+    #include <stdlib.h>  // NOLINT(build/include)
+#elif defined(__APPLE__)
+    // Mac OS X / Darwin features
+    #include <libkern/OSByteOrder.h>
+#elif defined(__FreeBSD__)
+    #include <sys/endian.h>
+#elif defined(__GLIBC__)
+    #include <byteswap.h>  // IWYU pragma: export
+#endif
+
+#include <string.h>
+#include <cstdint>
+#include "phmap_config.h"
+
+// -----------------------------------------------------------------------------
+// unaligned APIs
+// -----------------------------------------------------------------------------
+// Portable handling of unaligned loads, stores, and copies.
+// On some platforms, like ARM, the copy functions can be more efficient
+// then a load and a store.
+// -----------------------------------------------------------------------------
+
+#if defined(ADDRESS_SANITIZER) || defined(THREAD_SANITIZER) ||\
+    defined(MEMORY_SANITIZER)
+#include <stdint.h>
+
+extern "C" {
+    uint16_t __sanitizer_unaligned_load16(const void *p);
+    uint32_t __sanitizer_unaligned_load32(const void *p);
+    uint64_t __sanitizer_unaligned_load64(const void *p);
+    void __sanitizer_unaligned_store16(void *p, uint16_t v);
+    void __sanitizer_unaligned_store32(void *p, uint32_t v);
+    void __sanitizer_unaligned_store64(void *p, uint64_t v);
+}  // extern "C"
+
+namespace phmap {
+namespace bits {
+
+inline uint16_t UnalignedLoad16(const void *p) {
+  return __sanitizer_unaligned_load16(p);
+}
+
+inline uint32_t UnalignedLoad32(const void *p) {
+  return __sanitizer_unaligned_load32(p);
+}
+
+inline uint64_t UnalignedLoad64(const void *p) {
+  return __sanitizer_unaligned_load64(p);
+}
+
+inline void UnalignedStore16(void *p, uint16_t v) {
+  __sanitizer_unaligned_store16(p, v);
+}
+
+inline void UnalignedStore32(void *p, uint32_t v) {
+  __sanitizer_unaligned_store32(p, v);
+}
+
+inline void UnalignedStore64(void *p, uint64_t v) {
+  __sanitizer_unaligned_store64(p, v);
+}
+
+}  // namespace bits
+}  // namespace phmap
+
+#define PHMAP_INTERNAL_UNALIGNED_LOAD16(_p) (phmap::bits::UnalignedLoad16(_p))
+#define PHMAP_INTERNAL_UNALIGNED_LOAD32(_p) (phmap::bits::UnalignedLoad32(_p))
+#define PHMAP_INTERNAL_UNALIGNED_LOAD64(_p) (phmap::bits::UnalignedLoad64(_p))
+
+#define PHMAP_INTERNAL_UNALIGNED_STORE16(_p, _val) (phmap::bits::UnalignedStore16(_p, _val))
+#define PHMAP_INTERNAL_UNALIGNED_STORE32(_p, _val) (phmap::bits::UnalignedStore32(_p, _val))
+#define PHMAP_INTERNAL_UNALIGNED_STORE64(_p, _val) (phmap::bits::UnalignedStore64(_p, _val))
+
+#elif defined(UNDEFINED_BEHAVIOR_SANITIZER)
+
+namespace phmap {
+namespace bits {
+
+inline uint16_t UnalignedLoad16(const void *p) {
+  uint16_t t;
+  memcpy(&t, p, sizeof t);
+  return t;
+}
+
+inline uint32_t UnalignedLoad32(const void *p) {
+  uint32_t t;
+  memcpy(&t, p, sizeof t);
+  return t;
+}
+
+inline uint64_t UnalignedLoad64(const void *p) {
+  uint64_t t;
+  memcpy(&t, p, sizeof t);
+  return t;
+}
+
+inline void UnalignedStore16(void *p, uint16_t v) { memcpy(p, &v, sizeof v); }
+
+inline void UnalignedStore32(void *p, uint32_t v) { memcpy(p, &v, sizeof v); }
+
+inline void UnalignedStore64(void *p, uint64_t v) { memcpy(p, &v, sizeof v); }
+
+}  // namespace bits
+}  // namespace phmap
+
+#define PHMAP_INTERNAL_UNALIGNED_LOAD16(_p) \
+  (phmap::bits::UnalignedLoad16(_p))
+#define PHMAP_INTERNAL_UNALIGNED_LOAD32(_p) \
+  (phmap::bits::UnalignedLoad32(_p))
+#define PHMAP_INTERNAL_UNALIGNED_LOAD64(_p) \
+  (phmap::bits::UnalignedLoad64(_p))
+
+#define PHMAP_INTERNAL_UNALIGNED_STORE16(_p, _val) \
+  (phmap::bits::UnalignedStore16(_p, _val))
+#define PHMAP_INTERNAL_UNALIGNED_STORE32(_p, _val) \
+  (phmap::bits::UnalignedStore32(_p, _val))
+#define PHMAP_INTERNAL_UNALIGNED_STORE64(_p, _val) \
+  (phmap::bits::UnalignedStore64(_p, _val))
+
+#elif defined(__x86_64__) || defined(_M_X64) || defined(__i386) || \
+    defined(_M_IX86) || defined(__ppc__) || defined(__PPC__) ||    \
+    defined(__ppc64__) || defined(__PPC64__)
+
+// x86 and x86-64 can perform unaligned loads/stores directly;
+// modern PowerPC hardware can also do unaligned integer loads and stores;
+// but note: the FPU still sends unaligned loads and stores to a trap handler!
+
+#define PHMAP_INTERNAL_UNALIGNED_LOAD16(_p) \
+  (*reinterpret_cast<const uint16_t *>(_p))
+#define PHMAP_INTERNAL_UNALIGNED_LOAD32(_p) \
+  (*reinterpret_cast<const uint32_t *>(_p))
+#define PHMAP_INTERNAL_UNALIGNED_LOAD64(_p) \
+  (*reinterpret_cast<const uint64_t *>(_p))
+
+#define PHMAP_INTERNAL_UNALIGNED_STORE16(_p, _val) \
+  (*reinterpret_cast<uint16_t *>(_p) = (_val))
+#define PHMAP_INTERNAL_UNALIGNED_STORE32(_p, _val) \
+  (*reinterpret_cast<uint32_t *>(_p) = (_val))
+#define PHMAP_INTERNAL_UNALIGNED_STORE64(_p, _val) \
+  (*reinterpret_cast<uint64_t *>(_p) = (_val))
+
+#elif defined(__arm__) && \
+      !defined(__ARM_ARCH_5__) && \
+      !defined(__ARM_ARCH_5T__) && \
+      !defined(__ARM_ARCH_5TE__) && \
+      !defined(__ARM_ARCH_5TEJ__) && \
+      !defined(__ARM_ARCH_6__) && \
+      !defined(__ARM_ARCH_6J__) && \
+      !defined(__ARM_ARCH_6K__) && \
+      !defined(__ARM_ARCH_6Z__) && \
+      !defined(__ARM_ARCH_6ZK__) && \
+      !defined(__ARM_ARCH_6T2__)
+
+
+namespace phmap {
+namespace bits {
+
+struct Unaligned16Struct 
+{
+    uint16_t value;
+    uint8_t dummy;  // To make the size non-power-of-two.
+} PHMAP_ATTRIBUTE_PACKED;
+
+struct Unaligned32Struct 
+{
+    uint32_t value;
+    uint8_t dummy;  // To make the size non-power-of-two.
+} PHMAP_ATTRIBUTE_PACKED;
+
+}  // namespace bits
+}  // namespace phmap
+
+#define PHMAP_INTERNAL_UNALIGNED_LOAD16(_p)                                  \
+  ((reinterpret_cast<const ::phmap::bits::Unaligned16Struct *>(_p))->value)
+#define PHMAP_INTERNAL_UNALIGNED_LOAD32(_p)                                  \
+  ((reinterpret_cast<const ::phmap::bits::Unaligned32Struct *>(_p))->value)
+
+#define PHMAP_INTERNAL_UNALIGNED_STORE16(_p, _val)                      \
+  ((reinterpret_cast< ::phmap::bits::Unaligned16Struct *>(_p))->value = (_val))
+#define PHMAP_INTERNAL_UNALIGNED_STORE32(_p, _val)                      \
+  ((reinterpret_cast< ::phmap::bits::Unaligned32Struct *>(_p))->value = (_val))
+
+namespace phmap {
+namespace bits {
+
+inline uint64_t UnalignedLoad64(const void *p) 
+{
+    uint64_t t;
+    memcpy(&t, p, sizeof t);
+    return t;
+}
+
+inline void UnalignedStore64(void *p, uint64_t v) { memcpy(p, &v, sizeof v); }
+
+}  // namespace bits
+}  // namespace phmap
+
+#define PHMAP_INTERNAL_UNALIGNED_LOAD64(_p) \
+  (phmap::bits::UnalignedLoad64(_p))
+#define PHMAP_INTERNAL_UNALIGNED_STORE64(_p, _val) \
+  (phmap::bits::UnalignedStore64(_p, _val))
+
+#else
+
+// PHMAP_INTERNAL_NEED_ALIGNED_LOADS is defined when the underlying platform
+// doesn't support unaligned access.
+#define PHMAP_INTERNAL_NEED_ALIGNED_LOADS
+
+// These functions are provided for architectures that don't support
+// unaligned loads and stores.
+
+namespace phmap {
+namespace bits {
+
+inline uint16_t UnalignedLoad16(const void *p) {
+  uint16_t t;
+  memcpy(&t, p, sizeof t);
+  return t;
+}
+
+inline uint32_t UnalignedLoad32(const void *p) {
+  uint32_t t;
+  memcpy(&t, p, sizeof t);
+  return t;
+}
+
+inline uint64_t UnalignedLoad64(const void *p) {
+  uint64_t t;
+  memcpy(&t, p, sizeof t);
+  return t;
+}
+
+inline void UnalignedStore16(void *p, uint16_t v) { memcpy(p, &v, sizeof v); }
+
+inline void UnalignedStore32(void *p, uint32_t v) { memcpy(p, &v, sizeof v); }
+
+inline void UnalignedStore64(void *p, uint64_t v) { memcpy(p, &v, sizeof v); }
+
+}  // namespace bits
+}  // namespace phmap
+
+#define PHMAP_INTERNAL_UNALIGNED_LOAD16(_p) (phmap::bits::UnalignedLoad16(_p))
+#define PHMAP_INTERNAL_UNALIGNED_LOAD32(_p) (phmap::bits::UnalignedLoad32(_p))
+#define PHMAP_INTERNAL_UNALIGNED_LOAD64(_p) (phmap::bits::UnalignedLoad64(_p))
+
+#define PHMAP_INTERNAL_UNALIGNED_STORE16(_p, _val) (phmap::bits::UnalignedStore16(_p, _val))
+#define PHMAP_INTERNAL_UNALIGNED_STORE32(_p, _val) (phmap::bits::UnalignedStore32(_p, _val))
+#define PHMAP_INTERNAL_UNALIGNED_STORE64(_p, _val) (phmap::bits::UnalignedStore64(_p, _val))
+
+#endif
+
+// -----------------------------------------------------------------------------
+// File: optimization.h
+// -----------------------------------------------------------------------------
+
+#if defined(__pnacl__)
+    #define PHMAP_BLOCK_TAIL_CALL_OPTIMIZATION() if (volatile int x = 0) { (void)x; }
+#elif defined(__clang__)
+    // Clang will not tail call given inline volatile assembly.
+    #define PHMAP_BLOCK_TAIL_CALL_OPTIMIZATION() __asm__ __volatile__("")
+#elif defined(__GNUC__)
+    // GCC will not tail call given inline volatile assembly.
+    #define PHMAP_BLOCK_TAIL_CALL_OPTIMIZATION() __asm__ __volatile__("")
+#elif defined(_MSC_VER)
+    #include <intrin.h>
+    // The __nop() intrinsic blocks the optimisation.
+    #define PHMAP_BLOCK_TAIL_CALL_OPTIMIZATION() __nop()
+#else
+    #define PHMAP_BLOCK_TAIL_CALL_OPTIMIZATION() if (volatile int x = 0) { (void)x; }
+#endif
+
+#if defined(__GNUC__)
+    // Cache line alignment
+    #if defined(__i386__) || defined(__x86_64__)
+        #define PHMAP_CACHELINE_SIZE 64
+    #elif defined(__powerpc64__)
+        #define PHMAP_CACHELINE_SIZE 128
+    #elif defined(__aarch64__)
+        // We would need to read special register ctr_el0 to find out L1 dcache size.
+        // This value is a good estimate based on a real aarch64 machine.
+        #define PHMAP_CACHELINE_SIZE 64
+    #elif defined(__arm__)
+        // Cache line sizes for ARM: These values are not strictly correct since
+        // cache line sizes depend on implementations, not architectures.  There
+        // are even implementations with cache line sizes configurable at boot
+        // time.
+        #if defined(__ARM_ARCH_5T__)
+            #define PHMAP_CACHELINE_SIZE 32
+        #elif defined(__ARM_ARCH_7A__)
+            #define PHMAP_CACHELINE_SIZE 64
+        #endif
+    #endif
+
+    #ifndef PHMAP_CACHELINE_SIZE
+        // A reasonable default guess.  Note that overestimates tend to waste more
+        // space, while underestimates tend to waste more time.
+        #define PHMAP_CACHELINE_SIZE 64
+    #endif
+
+    #define PHMAP_CACHELINE_ALIGNED __attribute__((aligned(PHMAP_CACHELINE_SIZE)))
+#elif defined(_MSC_VER)
+    #define PHMAP_CACHELINE_SIZE 64
+    #define PHMAP_CACHELINE_ALIGNED __declspec(align(PHMAP_CACHELINE_SIZE))
+#else
+    #define PHMAP_CACHELINE_SIZE 64
+    #define PHMAP_CACHELINE_ALIGNED
+#endif
+
+
+#if PHMAP_HAVE_BUILTIN(__builtin_expect) || \
+    (defined(__GNUC__) && !defined(__clang__))
+    #define PHMAP_PREDICT_FALSE(x) (__builtin_expect(x, 0))
+    #define PHMAP_PREDICT_TRUE(x) (__builtin_expect(!!(x), 1))
+#else
+    #define PHMAP_PREDICT_FALSE(x) (x)
+    #define PHMAP_PREDICT_TRUE(x) (x)
+#endif
+
+
+#endif // phmap_bits_h_guard_

parallel_hashmap/phmap_config.h

@@ -0,0 +1,631 @@
+#if !defined(phmap_config_h_guard_)
+#define phmap_config_h_guard_
+
+// ---------------------------------------------------------------------------
+// Copyright (c) 2019, Gregory Popovitch - greg7mdp@gmail.com
+//
+// 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
+//
+//      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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Includes work from abseil-cpp (https://github.com/abseil/abseil-cpp)
+// with modifications.
+// 
+// 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
+//
+//      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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ---------------------------------------------------------------------------
+
+
+// Included for the __GLIBC__ macro (or similar macros on other systems).
+#include <limits.h>
+
+#ifdef __cplusplus
+    // Included for __GLIBCXX__, _LIBCPP_VERSION
+    #include <cstddef>
+#endif  // __cplusplus
+
+#if defined(__APPLE__)
+    // Included for TARGET_OS_IPHONE, __IPHONE_OS_VERSION_MIN_REQUIRED,
+    // __IPHONE_8_0.
+    #include <Availability.h>
+    #include <TargetConditionals.h>
+#endif
+
+// -----------------------------------------------------------------------------
+// Some sanity checks
+// -----------------------------------------------------------------------------
+#if defined(__CYGWIN__)
+    #error "Cygwin is not supported."
+#endif
+
+#if defined(_MSC_FULL_VER) && _MSC_FULL_VER < 190023918 && !defined(__clang__)
+    #error "phmap requires Visual Studio 2015 Update 2 or higher."
+#endif
+
+// We support gcc 4.7 and later.
+#if defined(__GNUC__) && !defined(__clang__)
+    #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
+        #error "phmap requires gcc 4.7 or higher."
+    #endif
+#endif
+
+// We support Apple Xcode clang 4.2.1 (version 421.11.65) and later.
+// This corresponds to Apple Xcode version 4.5.
+#if defined(__apple_build_version__) && __apple_build_version__ < 4211165
+    #error "phmap requires __apple_build_version__ of 4211165 or higher."
+#endif
+
+// Enforce C++11 as the minimum. 
+#if defined(__cplusplus) && !defined(_MSC_VER)
+    #if __cplusplus < 201103L
+        #error "C++ versions less than C++11 are not supported."
+    #endif
+#endif
+
+// We have chosen glibc 2.12 as the minimum 
+#if defined(__GLIBC__) && defined(__GLIBC_PREREQ)
+    #if !__GLIBC_PREREQ(2, 12)
+        #error "Minimum required version of glibc is 2.12."
+    #endif
+#endif
+
+#if defined(_STLPORT_VERSION)
+    #error "STLPort is not supported."
+#endif
+
+#if CHAR_BIT != 8
+    #error "phmap assumes CHAR_BIT == 8."
+#endif
+
+// phmap currently assumes that an int is 4 bytes. 
+#if INT_MAX < 2147483647
+    #error "phmap assumes that int is at least 4 bytes. "
+#endif
+
+
+// -----------------------------------------------------------------------------
+// Compiler Feature Checks
+// -----------------------------------------------------------------------------
+
+#ifdef __has_builtin
+    #define PHMAP_HAVE_BUILTIN(x) __has_builtin(x)
+#else
+    #define PHMAP_HAVE_BUILTIN(x) 0
+#endif
+
+// ----------------------------------------------------------------
+// Checks whether `std::is_trivially_destructible<T>` is supported.
+// ----------------------------------------------------------------
+#ifdef PHMAP_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE
+    #error PHMAP_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE cannot be directly set
+#elif defined(_LIBCPP_VERSION) ||                                        \
+    (!defined(__clang__) && defined(__GNUC__) && defined(__GLIBCXX__) && \
+     (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))) ||        \
+    defined(_MSC_VER)
+    #define PHMAP_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE 1
+#endif
+
+// --------------------------------------------------------------
+// Checks whether `std::is_trivially_default_constructible<T>` is 
+// supported.
+// --------------------------------------------------------------
+#if defined(PHMAP_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE)
+    #error PHMAP_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE cannot be directly set
+#elif defined(PHMAP_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE)
+    #error PHMAP_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE cannot directly set
+#elif (defined(__clang__) && defined(_LIBCPP_VERSION)) ||        \
+    (!defined(__clang__) && defined(__GNUC__) &&                 \
+     (__GNUC__ > 5 || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1)) && \
+     (defined(_LIBCPP_VERSION) || defined(__GLIBCXX__))) ||      \
+    (defined(_MSC_VER) && !defined(__NVCC__))
+    #define PHMAP_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE 1
+    #define PHMAP_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE 1
+#endif
+
+// -------------------------------------------------------------------
+// Checks whether C++11's `thread_local` storage duration specifier is
+// supported.
+// -------------------------------------------------------------------
+#ifdef PHMAP_HAVE_THREAD_LOCAL
+    #error PHMAP_HAVE_THREAD_LOCAL cannot be directly set
+#elif defined(__APPLE__)
+    #if __has_feature(cxx_thread_local) && \
+        !(TARGET_OS_IPHONE && __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_9_0)
+        #define PHMAP_HAVE_THREAD_LOCAL 1
+    #endif
+#else  // !defined(__APPLE__)
+    #define PHMAP_HAVE_THREAD_LOCAL 1
+#endif
+
+#if defined(__ANDROID__) && defined(__clang__)
+
+    #if __has_include(<android/ndk-version.h>)
+        #include <android/ndk-version.h>
+    #endif  // __has_include(<android/ndk-version.h>)
+
+    #if defined(__ANDROID__) && defined(__clang__) && defined(__NDK_MAJOR__) && \
+        defined(__NDK_MINOR__) &&                                               \
+        ((__NDK_MAJOR__ < 12) || ((__NDK_MAJOR__ == 12) && (__NDK_MINOR__ < 1)))
+        #undef PHMAP_HAVE_TLS
+        #undef PHMAP_HAVE_THREAD_LOCAL
+    #endif
+#endif 
+
+// ------------------------------------------------------------
+// Checks whether the __int128 compiler extension for a 128-bit 
+// integral type is supported.
+// ------------------------------------------------------------
+#ifdef PHMAP_HAVE_INTRINSIC_INT128
+    #error PHMAP_HAVE_INTRINSIC_INT128 cannot be directly set
+#elif defined(__SIZEOF_INT128__)
+    #if (defined(__clang__) && !defined(_WIN32) && !defined(__aarch64__)) || \
+        (defined(__CUDACC__) && __CUDACC_VER_MAJOR__ >= 9) ||                \
+        (defined(__GNUC__) && !defined(__clang__) && !defined(__CUDACC__))
+        #define PHMAP_HAVE_INTRINSIC_INT128 1
+    #elif defined(__CUDACC__)
+        #if __CUDACC_VER__ >= 70000
+            #define PHMAP_HAVE_INTRINSIC_INT128 1
+        #endif  // __CUDACC_VER__ >= 70000
+    #endif  // defined(__CUDACC__)
+#endif
+
+// ------------------------------------------------------------------
+// Checks whether the compiler both supports and enables exceptions. 
+// ------------------------------------------------------------------
+#ifdef PHMAP_HAVE_EXCEPTIONS
+    #error PHMAP_HAVE_EXCEPTIONS cannot be directly set.
+#elif defined(__clang__)
+    #if defined(__EXCEPTIONS) && __has_feature(cxx_exceptions)
+        #define PHMAP_HAVE_EXCEPTIONS 1
+    #endif  // defined(__EXCEPTIONS) && __has_feature(cxx_exceptions)
+#elif !(defined(__GNUC__) && (__GNUC__ < 5) && !defined(__EXCEPTIONS)) &&    \
+    !(defined(__GNUC__) && (__GNUC__ >= 5) && !defined(__cpp_exceptions)) && \
+    !(defined(_MSC_VER) && !defined(_CPPUNWIND))
+    #define PHMAP_HAVE_EXCEPTIONS 1
+#endif
+
+
+// -----------------------------------------------------------------------
+// Checks whether the platform has an mmap(2) implementation as defined in
+// POSIX.1-2001.
+// -----------------------------------------------------------------------
+#ifdef PHMAP_HAVE_MMAP
+    #error PHMAP_HAVE_MMAP cannot be directly set
+#elif defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__) ||   \
+    defined(__ros__) || defined(__native_client__) || defined(__asmjs__) || \
+    defined(__wasm__) || defined(__Fuchsia__) || defined(__sun) || \
+    defined(__ASYLO__)
+    #define PHMAP_HAVE_MMAP 1
+#endif
+
+// -----------------------------------------------------------------------
+// Checks the endianness of the platform.
+// -----------------------------------------------------------------------
+#if defined(PHMAP_IS_BIG_ENDIAN)
+    #error "PHMAP_IS_BIG_ENDIAN cannot be directly set."
+#endif
+
+#if defined(PHMAP_IS_LITTLE_ENDIAN)
+    #error "PHMAP_IS_LITTLE_ENDIAN cannot be directly set."
+#endif
+
+#if (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
+     __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+    #define PHMAP_IS_LITTLE_ENDIAN 1
+#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \
+    __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+    #define PHMAP_IS_BIG_ENDIAN 1
+#elif defined(_WIN32)
+    #define PHMAP_IS_LITTLE_ENDIAN 1
+#else
+    #error "phmap endian detection needs to be set up for your compiler"
+#endif
+
+#if defined(__APPLE__) && defined(_LIBCPP_VERSION) && \
+    defined(__MAC_OS_X_VERSION_MIN_REQUIRED__) &&     \
+    __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 101400
+    #define PHMAP_INTERNAL_MACOS_CXX17_TYPES_UNAVAILABLE 1
+#else
+    #define PHMAP_INTERNAL_MACOS_CXX17_TYPES_UNAVAILABLE 0
+#endif
+
+// ---------------------------------------------------------------------------
+// Checks whether C++17 std::any is available by checking whether <any> exists.
+// ---------------------------------------------------------------------------
+#ifdef PHMAP_HAVE_STD_ANY
+    #error "PHMAP_HAVE_STD_ANY cannot be directly set."
+#endif
+
+#ifdef __has_include
+    #if __has_include(<any>) && __cplusplus >= 201703L && \
+        !PHMAP_INTERNAL_MACOS_CXX17_TYPES_UNAVAILABLE
+        #define PHMAP_HAVE_STD_ANY 1
+    #endif
+#endif
+
+#ifdef PHMAP_HAVE_STD_OPTIONAL
+    #error "PHMAP_HAVE_STD_OPTIONAL cannot be directly set."
+#endif
+
+#ifdef __has_include
+    #if __has_include(<optional>) && __cplusplus >= 201703L && \
+        !PHMAP_INTERNAL_MACOS_CXX17_TYPES_UNAVAILABLE
+        #define PHMAP_HAVE_STD_OPTIONAL 1
+    #endif
+#endif
+
+#ifdef PHMAP_HAVE_STD_VARIANT
+    #error "PHMAP_HAVE_STD_VARIANT cannot be directly set."
+#endif
+
+#ifdef __has_include
+    #if __has_include(<variant>) && __cplusplus >= 201703L && \
+        !PHMAP_INTERNAL_MACOS_CXX17_TYPES_UNAVAILABLE
+        #define PHMAP_HAVE_STD_VARIANT 1
+    #endif
+#endif
+
+#ifdef PHMAP_HAVE_STD_STRING_VIEW
+    #error "PHMAP_HAVE_STD_STRING_VIEW cannot be directly set."
+#endif
+
+#ifdef __has_include
+    #if __has_include(<string_view>) && __cplusplus >= 201703L
+        #define PHMAP_HAVE_STD_STRING_VIEW 1
+    #endif
+#endif
+
+#if defined(_MSC_VER) && _MSC_VER >= 1910 && \
+    ((defined(_MSVC_LANG) && _MSVC_LANG > 201402) || __cplusplus > 201402)
+    // #define PHMAP_HAVE_STD_ANY 1
+    #define PHMAP_HAVE_STD_OPTIONAL 1
+    #define PHMAP_HAVE_STD_VARIANT 1
+    #define PHMAP_HAVE_STD_STRING_VIEW 1
+#endif
+
+// In debug mode, MSVC 2017's std::variant throws a EXCEPTION_ACCESS_VIOLATION
+// SEH exception from emplace for variant<SomeStruct> when constructing the
+// struct can throw. This defeats some of variant_test and
+// variant_exception_safety_test.
+#if defined(_MSC_VER) && _MSC_VER >= 1700 && defined(_DEBUG)
+    #define PHMAP_INTERNAL_MSVC_2017_DBG_MODE
+#endif
+
+
+// -----------------------------------------------------------------------------
+// Sanitizer Attributes
+// -----------------------------------------------------------------------------
+//
+// Sanitizer-related attributes are not "defined" in this file (and indeed
+// are not defined as such in any file). To utilize the following
+// sanitizer-related attributes within your builds, define the following macros
+// within your build using a `-D` flag, along with the given value for
+// `-fsanitize`:
+//
+//   * `ADDRESS_SANITIZER` + `-fsanitize=address` (Clang, GCC 4.8)
+//   * `MEMORY_SANITIZER` + `-fsanitize=memory` (Clang-only)
+//   * `THREAD_SANITIZER + `-fsanitize=thread` (Clang, GCC 4.8+)
+//   * `UNDEFINED_BEHAVIOR_SANITIZER` + `-fsanitize=undefined` (Clang, GCC 4.9+)
+//   * `CONTROL_FLOW_INTEGRITY` + -fsanitize=cfi (Clang-only)
+// -----------------------------------------------------------------------------
+
+// -----------------------------------------------------------------------------
+// A function-like feature checking macro that is a wrapper around
+// `__has_attribute`, which is defined by GCC 5+ and Clang and evaluates to a
+// nonzero constant integer if the attribute is supported or 0 if not.
+//
+// It evaluates to zero if `__has_attribute` is not defined by the compiler.
+// -----------------------------------------------------------------------------
+#ifdef __has_attribute
+    #define PHMAP_HAVE_ATTRIBUTE(x) __has_attribute(x)
+#else
+    #define PHMAP_HAVE_ATTRIBUTE(x) 0
+#endif
+
+// -----------------------------------------------------------------------------
+// A function-like feature checking macro that accepts C++11 style attributes.
+// It's a wrapper around `__has_cpp_attribute`, defined by ISO C++ SD-6
+// (https://en.cppreference.com/w/cpp/experimental/feature_test). If we don't
+// find `__has_cpp_attribute`, will evaluate to 0.
+// -----------------------------------------------------------------------------
+#if defined(__cplusplus) && defined(__has_cpp_attribute)
+    #define PHMAP_HAVE_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
+#else
+    #define PHMAP_HAVE_CPP_ATTRIBUTE(x) 0
+#endif
+
+// -----------------------------------------------------------------------------
+// Function Attributes
+// -----------------------------------------------------------------------------
+#if PHMAP_HAVE_ATTRIBUTE(format) || (defined(__GNUC__) && !defined(__clang__))
+    #define PHMAP_PRINTF_ATTRIBUTE(string_index, first_to_check) \
+      __attribute__((__format__(__printf__, string_index, first_to_check)))
+    #define PHMAP_SCANF_ATTRIBUTE(string_index, first_to_check) \
+      __attribute__((__format__(__scanf__, string_index, first_to_check)))
+#else
+    #define PHMAP_PRINTF_ATTRIBUTE(string_index, first_to_check)
+    #define PHMAP_SCANF_ATTRIBUTE(string_index, first_to_check)
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(always_inline) || \
+    (defined(__GNUC__) && !defined(__clang__))
+    #define PHMAP_ATTRIBUTE_ALWAYS_INLINE __attribute__((always_inline))
+    #define PHMAP_HAVE_ATTRIBUTE_ALWAYS_INLINE 1
+#else
+    #define PHMAP_ATTRIBUTE_ALWAYS_INLINE
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(noinline) || (defined(__GNUC__) && !defined(__clang__))
+    #define PHMAP_ATTRIBUTE_NOINLINE __attribute__((noinline))
+    #define PHMAP_HAVE_ATTRIBUTE_NOINLINE 1
+#else
+    #define PHMAP_ATTRIBUTE_NOINLINE
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(disable_tail_calls)
+    #define PHMAP_HAVE_ATTRIBUTE_NO_TAIL_CALL 1
+    #define PHMAP_ATTRIBUTE_NO_TAIL_CALL __attribute__((disable_tail_calls))
+#elif defined(__GNUC__) && !defined(__clang__)
+    #define PHMAP_HAVE_ATTRIBUTE_NO_TAIL_CALL 1
+    #define PHMAP_ATTRIBUTE_NO_TAIL_CALL \
+      __attribute__((optimize("no-optimize-sibling-calls")))
+#else
+    #define PHMAP_ATTRIBUTE_NO_TAIL_CALL
+    #define PHMAP_HAVE_ATTRIBUTE_NO_TAIL_CALL 0
+#endif
+
+#if (PHMAP_HAVE_ATTRIBUTE(weak) || \
+     (defined(__GNUC__) && !defined(__clang__))) && \
+    !(defined(__llvm__) && defined(_WIN32))
+    #undef PHMAP_ATTRIBUTE_WEAK
+    #define PHMAP_ATTRIBUTE_WEAK __attribute__((weak))
+    #define PHMAP_HAVE_ATTRIBUTE_WEAK 1
+#else
+    #define PHMAP_ATTRIBUTE_WEAK
+    #define PHMAP_HAVE_ATTRIBUTE_WEAK 0
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(nonnull) || (defined(__GNUC__) && !defined(__clang__))
+    #define PHMAP_ATTRIBUTE_NONNULL(arg_index) __attribute__((nonnull(arg_index)))
+#else
+    #define PHMAP_ATTRIBUTE_NONNULL(...)
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(noreturn) || (defined(__GNUC__) && !defined(__clang__))
+    #define PHMAP_ATTRIBUTE_NORETURN __attribute__((noreturn))
+#elif defined(_MSC_VER)
+    #define PHMAP_ATTRIBUTE_NORETURN __declspec(noreturn)
+#else
+    #define PHMAP_ATTRIBUTE_NORETURN
+#endif
+
+#if defined(__GNUC__) && defined(ADDRESS_SANITIZER)
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_ADDRESS __attribute__((no_sanitize_address))
+#else
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_ADDRESS
+#endif
+
+#if defined(__GNUC__) && defined(MEMORY_SANITIZER)
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_MEMORY __attribute__((no_sanitize_memory))
+#else
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_MEMORY
+#endif
+
+#if defined(__GNUC__) && defined(THREAD_SANITIZER)
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_THREAD __attribute__((no_sanitize_thread))
+#else
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_THREAD
+#endif
+
+#if defined(__GNUC__) && \
+    (defined(UNDEFINED_BEHAVIOR_SANITIZER) || defined(ADDRESS_SANITIZER))
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_UNDEFINED \
+      __attribute__((no_sanitize("undefined")))
+#else
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_UNDEFINED
+#endif
+
+#if defined(__GNUC__) && defined(CONTROL_FLOW_INTEGRITY)
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_CFI __attribute__((no_sanitize("cfi")))
+#else
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_CFI
+#endif
+
+#if defined(__GNUC__) && defined(SAFESTACK_SANITIZER)
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_SAFESTACK \
+      __attribute__((no_sanitize("safe-stack")))
+#else
+    #define PHMAP_ATTRIBUTE_NO_SANITIZE_SAFESTACK
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(returns_nonnull) || \
+    (defined(__GNUC__) && \
+     (__GNUC__ > 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)) && \
+     !defined(__clang__))
+    #define PHMAP_ATTRIBUTE_RETURNS_NONNULL __attribute__((returns_nonnull))
+#else
+    #define PHMAP_ATTRIBUTE_RETURNS_NONNULL
+#endif
+
+#ifdef PHMAP_HAVE_ATTRIBUTE_SECTION
+    #error PHMAP_HAVE_ATTRIBUTE_SECTION cannot be directly set
+#elif (PHMAP_HAVE_ATTRIBUTE(section) ||                \
+       (defined(__GNUC__) && !defined(__clang__))) && \
+    !defined(__APPLE__) && PHMAP_HAVE_ATTRIBUTE_WEAK
+    #define PHMAP_HAVE_ATTRIBUTE_SECTION 1
+    #ifndef PHMAP_ATTRIBUTE_SECTION
+        #define PHMAP_ATTRIBUTE_SECTION(name) \
+          __attribute__((section(#name))) __attribute__((noinline))
+    #endif
+    #ifndef PHMAP_ATTRIBUTE_SECTION_VARIABLE
+        #define PHMAP_ATTRIBUTE_SECTION_VARIABLE(name) __attribute__((section(#name)))
+    #endif
+    #ifndef PHMAP_DECLARE_ATTRIBUTE_SECTION_VARS
+        #define PHMAP_DECLARE_ATTRIBUTE_SECTION_VARS(name) \
+          extern char __start_##name[] PHMAP_ATTRIBUTE_WEAK;    \
+          extern char __stop_##name[] PHMAP_ATTRIBUTE_WEAK
+    #endif
+    #ifndef PHMAP_DEFINE_ATTRIBUTE_SECTION_VARS
+        #define PHMAP_INIT_ATTRIBUTE_SECTION_VARS(name)
+        #define PHMAP_DEFINE_ATTRIBUTE_SECTION_VARS(name)
+    #endif
+    #define PHMAP_ATTRIBUTE_SECTION_START(name) \
+      (reinterpret_cast<void *>(__start_##name))
+    #define PHMAP_ATTRIBUTE_SECTION_STOP(name) \
+      (reinterpret_cast<void *>(__stop_##name))
+#else  // !PHMAP_HAVE_ATTRIBUTE_SECTION
+    #define PHMAP_HAVE_ATTRIBUTE_SECTION 0
+    #define PHMAP_ATTRIBUTE_SECTION(name)
+    #define PHMAP_ATTRIBUTE_SECTION_VARIABLE(name)
+    #define PHMAP_INIT_ATTRIBUTE_SECTION_VARS(name)
+    #define PHMAP_DEFINE_ATTRIBUTE_SECTION_VARS(name)
+    #define PHMAP_DECLARE_ATTRIBUTE_SECTION_VARS(name)
+    #define PHMAP_ATTRIBUTE_SECTION_START(name) (reinterpret_cast<void *>(0))
+    #define PHMAP_ATTRIBUTE_SECTION_STOP(name) (reinterpret_cast<void *>(0))
+#endif  // PHMAP_ATTRIBUTE_SECTION
+
+#if PHMAP_HAVE_ATTRIBUTE(force_align_arg_pointer) || \
+    (defined(__GNUC__) && !defined(__clang__))
+    #if defined(__i386__)
+        #define PHMAP_ATTRIBUTE_STACK_ALIGN_FOR_OLD_LIBC \
+          __attribute__((force_align_arg_pointer))
+        #define PHMAP_REQUIRE_STACK_ALIGN_TRAMPOLINE (0)
+    #elif defined(__x86_64__)
+        #define PHMAP_REQUIRE_STACK_ALIGN_TRAMPOLINE (1)
+        #define PHMAP_ATTRIBUTE_STACK_ALIGN_FOR_OLD_LIBC
+    #else  // !__i386__ && !__x86_64
+        #define PHMAP_REQUIRE_STACK_ALIGN_TRAMPOLINE (0)
+        #define PHMAP_ATTRIBUTE_STACK_ALIGN_FOR_OLD_LIBC
+    #endif  // __i386__
+#else
+    #define PHMAP_ATTRIBUTE_STACK_ALIGN_FOR_OLD_LIBC
+    #define PHMAP_REQUIRE_STACK_ALIGN_TRAMPOLINE (0)
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(nodiscard)
+    #define PHMAP_MUST_USE_RESULT [[nodiscard]]
+#elif defined(__clang__) && PHMAP_HAVE_ATTRIBUTE(warn_unused_result)
+    #define PHMAP_MUST_USE_RESULT __attribute__((warn_unused_result))
+#else
+    #define PHMAP_MUST_USE_RESULT
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(hot) || (defined(__GNUC__) && !defined(__clang__))
+    #define PHMAP_ATTRIBUTE_HOT __attribute__((hot))
+#else
+    #define PHMAP_ATTRIBUTE_HOT
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(cold) || (defined(__GNUC__) && !defined(__clang__))
+    #define PHMAP_ATTRIBUTE_COLD __attribute__((cold))
+#else
+    #define PHMAP_ATTRIBUTE_COLD
+#endif
+
+#if PHMAP_HAVE_CPP_ATTRIBUTE(clang::xray_always_instrument) && \
+    !defined(PHMAP_NO_XRAY_ATTRIBUTES)
+    #define PHMAP_XRAY_ALWAYS_INSTRUMENT [[clang::xray_always_instrument]]
+    #define PHMAP_XRAY_NEVER_INSTRUMENT [[clang::xray_never_instrument]]
+    #if PHMAP_HAVE_CPP_ATTRIBUTE(clang::xray_log_args)
+        #define PHMAP_XRAY_LOG_ARGS(N) \
+            [[clang::xray_always_instrument, clang::xray_log_args(N)]]
+    #else
+        #define PHMAP_XRAY_LOG_ARGS(N) [[clang::xray_always_instrument]]
+    #endif
+#else
+        #define PHMAP_XRAY_ALWAYS_INSTRUMENT
+        #define PHMAP_XRAY_NEVER_INSTRUMENT
+        #define PHMAP_XRAY_LOG_ARGS(N)
+#endif
+
+#if PHMAP_HAVE_CPP_ATTRIBUTE(clang::reinitializes)
+    #define PHMAP_ATTRIBUTE_REINITIALIZES [[clang::reinitializes]]
+#else
+    #define PHMAP_ATTRIBUTE_REINITIALIZES
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(unused) || (defined(__GNUC__) && !defined(__clang__))
+    #undef PHMAP_ATTRIBUTE_UNUSED
+    #define PHMAP_ATTRIBUTE_UNUSED __attribute__((__unused__))
+#else
+    #define PHMAP_ATTRIBUTE_UNUSED
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(tls_model) || (defined(__GNUC__) && !defined(__clang__))
+    #define PHMAP_ATTRIBUTE_INITIAL_EXEC __attribute__((tls_model("initial-exec")))
+#else
+    #define PHMAP_ATTRIBUTE_INITIAL_EXEC
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(packed) || (defined(__GNUC__) && !defined(__clang__))
+    #define PHMAP_ATTRIBUTE_PACKED __attribute__((__packed__))
+#else
+    #define PHMAP_ATTRIBUTE_PACKED
+#endif
+
+#if PHMAP_HAVE_ATTRIBUTE(aligned) || (defined(__GNUC__) && !defined(__clang__))
+    #define PHMAP_ATTRIBUTE_FUNC_ALIGN(bytes) __attribute__((aligned(bytes)))
+#else
+    #define PHMAP_ATTRIBUTE_FUNC_ALIGN(bytes)
+#endif
+
+#if PHMAP_HAVE_CPP_ATTRIBUTE(clang::require_constant_initialization)
+    #define PHMAP_CONST_INIT [[clang::require_constant_initialization]]
+#else
+    #define PHMAP_CONST_INIT
+#endif  // PHMAP_HAVE_CPP_ATTRIBUTE(clang::require_constant_initialization)
+
+
+// ----------------------------------------------------------------------
+// Figure out SSE support
+// ----------------------------------------------------------------------
+#ifndef PHMAP_HAVE_SSE2
+    #if defined(__SSE2__) ||  \
+        (defined(_MSC_VER) && \
+         (defined(_M_X64) || (defined(_M_IX86) && _M_IX86_FP >= 2)))
+        #define PHMAP_HAVE_SSE2 1
+    #else
+        #define PHMAP_HAVE_SSE2 0
+    #endif
+#endif
+
+#ifndef PHMAP_HAVE_SSSE3
+    #ifdef __SSSE3__
+        #define PHMAP_HAVE_SSSE3 1
+    #else
+        #define PHMAP_HAVE_SSSE3 0
+    #endif
+#endif
+
+#if PHMAP_HAVE_SSSE3 && !PHMAP_HAVE_SSE2
+    #error "Bad configuration!"
+#endif
+
+#if PHMAP_HAVE_SSE2
+    #include <emmintrin.h>
+#endif
+
+#if PHMAP_HAVE_SSSE3
+    #include <tmmintrin.h>
+#endif
+
+#endif // phmap_config_h_guard_

parallel_hashmap/phmap_utils.h

@@ -0,0 +1,40 @@
+#if !defined(phmap_utils_h_guard_)
+#define phmap_utils_h_guard_
+
+// ---------------------------------------------------------------------------
+// Copyright (c) 2019, Gregory Popovitch - greg7mdp@gmail.com
+//
+// 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
+//
+//      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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Includes work from abseil-cpp (https://github.com/abseil/abseil-cpp)
+// with modifications.
+// 
+// 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
+//
+//      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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ---------------------------------------------------------------------------
+
+
+
+
+#endif // phmap_utils_h_guard_