Abseil Common Libraries (C++) (grcp 依赖) https://abseil.io/
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Export of internal Abseil changes -- f012012ef78234a6a4585321b67d7b7c92ebc266 by Laramie Leavitt <lar@google.com>: Slight restructuring of absl/random/internal randen implementation. Convert round-keys.inc into randen_round_keys.cc file. Consistently use a 128-bit pointer type for internal method parameters. This allows simpler pointer arithmetic in C++ & permits removal of some constants and casts. Remove some redundancy in comments & constexpr variables. Specifically, all references to Randen algorithm parameters use RandenTraits; duplication in RandenSlow removed. PiperOrigin-RevId: 312190313 -- dc8b42e054046741e9ed65335bfdface997c6063 by Abseil Team <absl-team@google.com>: Internal change. PiperOrigin-RevId: 312167304 -- f13d248fafaf206492c1362c3574031aea3abaf7 by Matthew Brown <matthewbr@google.com>: Cleanup StrFormat extensions a little. PiperOrigin-RevId: 312166336 -- 9d9117589667afe2332bb7ad42bc967ca7c54502 by Derek Mauro <dmauro@google.com>: Internal change PiperOrigin-RevId: 312105213 -- 9a12b9b3aa0e59b8ee6cf9408ed0029045543a9b by Abseil Team <absl-team@google.com>: Complete IGNORE_TYPE macro renaming. PiperOrigin-RevId: 311999699 -- 64756f20d61021d999bd0d4c15e9ad3857382f57 by Gennadiy Rozental <rogeeff@google.com>: Switch to fixed bytes specific default value. This fixes the Abseil Flags for big endian platforms. PiperOrigin-RevId: 311844448 -- bdbe6b5b29791dbc3816ada1828458b3010ff1e9 by Laramie Leavitt <lar@google.com>: Change many distribution tests to use pcg_engine as a deterministic source of entropy. It's reasonable to test that the BitGen itself has good entropy, however when testing the cross product of all random distributions x all the architecture variations x all submitted changes results in a large number of tests. In order to account for these failures while still using good entropy requires that our allowed sigma need to account for all of these independent tests. Our current sigma values are too restrictive, and we see a lot of failures, so we have to either relax the sigma values or convert some of the statistical tests to use deterministic values. This changelist does the latter. PiperOrigin-RevId: 311840096 GitOrigin-RevId: f012012ef78234a6a4585321b67d7b7c92ebc266 Change-Id: Ic84886f38ff30d7d72c126e9b63c9a61eb729a1a
5 years ago
// Copyright 2017 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.
//
// -----------------------------------------------------------------------------
// File: memory.h
// -----------------------------------------------------------------------------
//
// This header file contains utility functions for managing the creation and
// conversion of smart pointers. This file is an extension to the C++
// standard <memory> library header file.
#ifndef ABSL_MEMORY_MEMORY_H_
#define ABSL_MEMORY_MEMORY_H_
#include <cstddef>
#include <limits>
#include <memory>
#include <new>
#include <type_traits>
#include <utility>
#include "absl/base/macros.h"
#include "absl/meta/type_traits.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
// -----------------------------------------------------------------------------
// Function Template: WrapUnique()
// -----------------------------------------------------------------------------
//
// Adopts ownership from a raw pointer and transfers it to the returned
// `std::unique_ptr`, whose type is deduced. Because of this deduction, *do not*
// specify the template type `T` when calling `WrapUnique`.
//
// Example:
// X* NewX(int, int);
// auto x = WrapUnique(NewX(1, 2)); // 'x' is std::unique_ptr<X>.
//
// Do not call WrapUnique with an explicit type, as in
// `WrapUnique<X>(NewX(1, 2))`. The purpose of WrapUnique is to automatically
// deduce the pointer type. If you wish to make the type explicit, just use
// `std::unique_ptr` directly.
//
// auto x = std::unique_ptr<X>(NewX(1, 2));
// - or -
// std::unique_ptr<X> x(NewX(1, 2));
//
// While `absl::WrapUnique` is useful for capturing the output of a raw
// pointer factory, prefer 'absl::make_unique<T>(args...)' over
// 'absl::WrapUnique(new T(args...))'.
//
// auto x = WrapUnique(new X(1, 2)); // works, but nonideal.
// auto x = make_unique<X>(1, 2); // safer, standard, avoids raw 'new'.
//
// Note that `absl::WrapUnique(p)` is valid only if `delete p` is a valid
// expression. In particular, `absl::WrapUnique()` cannot wrap pointers to
// arrays, functions or void, and it must not be used to capture pointers
// obtained from array-new expressions (even though that would compile!).
template <typename T>
std::unique_ptr<T> WrapUnique(T* ptr) {
static_assert(!std::is_array<T>::value, "array types are unsupported");
static_assert(std::is_object<T>::value, "non-object types are unsupported");
return std::unique_ptr<T>(ptr);
}
namespace memory_internal {
// Traits to select proper overload and return type for `absl::make_unique<>`.
template <typename T>
struct MakeUniqueResult {
using scalar = std::unique_ptr<T>;
};
template <typename T>
struct MakeUniqueResult<T[]> {
using array = std::unique_ptr<T[]>;
};
template <typename T, size_t N>
struct MakeUniqueResult<T[N]> {
using invalid = void;
};
} // namespace memory_internal
// gcc 4.8 has __cplusplus at 201301 but the libstdc++ shipped with it doesn't
// define make_unique. Other supported compilers either just define __cplusplus
// as 201103 but have make_unique (msvc), or have make_unique whenever
// __cplusplus > 201103 (clang).
#if (__cplusplus > 201103L || defined(_MSC_VER)) && \
!(defined(__GLIBCXX__) && !defined(__cpp_lib_make_unique))
using std::make_unique;
#else
// -----------------------------------------------------------------------------
// Function Template: make_unique<T>()
// -----------------------------------------------------------------------------
//
// Creates a `std::unique_ptr<>`, while avoiding issues creating temporaries
// during the construction process. `absl::make_unique<>` also avoids redundant
// type declarations, by avoiding the need to explicitly use the `new` operator.
//
// This implementation of `absl::make_unique<>` is designed for C++11 code and
// will be replaced in C++14 by the equivalent `std::make_unique<>` abstraction.
// `absl::make_unique<>` is designed to be 100% compatible with
// `std::make_unique<>` so that the eventual migration will involve a simple
// rename operation.
//
// For more background on why `std::unique_ptr<T>(new T(a,b))` is problematic,
// see Herb Sutter's explanation on
// (Exception-Safe Function Calls)[https://herbsutter.com/gotw/_102/].
// (In general, reviewers should treat `new T(a,b)` with scrutiny.)
//
// Example usage:
//
// auto p = make_unique<X>(args...); // 'p' is a std::unique_ptr<X>
// auto pa = make_unique<X[]>(5); // 'pa' is a std::unique_ptr<X[]>
//
// Three overloads of `absl::make_unique` are required:
//
// - For non-array T:
//
// Allocates a T with `new T(std::forward<Args> args...)`,
// forwarding all `args` to T's constructor.
// Returns a `std::unique_ptr<T>` owning that object.
//
// - For an array of unknown bounds T[]:
//
// `absl::make_unique<>` will allocate an array T of type U[] with
// `new U[n]()` and return a `std::unique_ptr<U[]>` owning that array.
//
// Note that 'U[n]()' is different from 'U[n]', and elements will be
// value-initialized. Note as well that `std::unique_ptr` will perform its
// own destruction of the array elements upon leaving scope, even though
// the array [] does not have a default destructor.
//
// NOTE: an array of unknown bounds T[] may still be (and often will be)
// initialized to have a size, and will still use this overload. E.g:
//
// auto my_array = absl::make_unique<int[]>(10);
//
// - For an array of known bounds T[N]:
//
// `absl::make_unique<>` is deleted (like with `std::make_unique<>`) as
// this overload is not useful.
//
// NOTE: an array of known bounds T[N] is not considered a useful
// construction, and may cause undefined behavior in templates. E.g:
//
// auto my_array = absl::make_unique<int[10]>();
//
// In those cases, of course, you can still use the overload above and
// simply initialize it to its desired size:
//
// auto my_array = absl::make_unique<int[]>(10);
// `absl::make_unique` overload for non-array types.
template <typename T, typename... Args>
typename memory_internal::MakeUniqueResult<T>::scalar make_unique(
Args&&... args) {
return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
}
// `absl::make_unique` overload for an array T[] of unknown bounds.
// The array allocation needs to use the `new T[size]` form and cannot take
// element constructor arguments. The `std::unique_ptr` will manage destructing
// these array elements.
template <typename T>
typename memory_internal::MakeUniqueResult<T>::array make_unique(size_t n) {
return std::unique_ptr<T>(new typename absl::remove_extent_t<T>[n]());
}
// `absl::make_unique` overload for an array T[N] of known bounds.
// This construction will be rejected.
template <typename T, typename... Args>
typename memory_internal::MakeUniqueResult<T>::invalid make_unique(
Args&&... /* args */) = delete;
#endif
// -----------------------------------------------------------------------------
// Function Template: RawPtr()
// -----------------------------------------------------------------------------
//
// Extracts the raw pointer from a pointer-like value `ptr`. `absl::RawPtr` is
// useful within templates that need to handle a complement of raw pointers,
// `std::nullptr_t`, and smart pointers.
template <typename T>
auto RawPtr(T&& ptr) -> decltype(std::addressof(*ptr)) {
// ptr is a forwarding reference to support Ts with non-const operators.
return (ptr != nullptr) ? std::addressof(*ptr) : nullptr;
}
inline std::nullptr_t RawPtr(std::nullptr_t) { return nullptr; }
// -----------------------------------------------------------------------------
// Function Template: ShareUniquePtr()
// -----------------------------------------------------------------------------
//
// Adopts a `std::unique_ptr` rvalue and returns a `std::shared_ptr` of deduced
// type. Ownership (if any) of the held value is transferred to the returned
// shared pointer.
//
// Example:
//
// auto up = absl::make_unique<int>(10);
// auto sp = absl::ShareUniquePtr(std::move(up)); // shared_ptr<int>
// CHECK_EQ(*sp, 10);
// CHECK(up == nullptr);
//
// Note that this conversion is correct even when T is an array type, and more
// generally it works for *any* deleter of the `unique_ptr` (single-object
// deleter, array deleter, or any custom deleter), since the deleter is adopted
// by the shared pointer as well. The deleter is copied (unless it is a
// reference).
//
// Implements the resolution of [LWG 2415](http://wg21.link/lwg2415), by which a
// null shared pointer does not attempt to call the deleter.
template <typename T, typename D>
std::shared_ptr<T> ShareUniquePtr(std::unique_ptr<T, D>&& ptr) {
return ptr ? std::shared_ptr<T>(std::move(ptr)) : std::shared_ptr<T>();
}
// -----------------------------------------------------------------------------
// Function Template: WeakenPtr()
// -----------------------------------------------------------------------------
//
// Creates a weak pointer associated with a given shared pointer. The returned
// value is a `std::weak_ptr` of deduced type.
//
// Example:
//
// auto sp = std::make_shared<int>(10);
// auto wp = absl::WeakenPtr(sp);
// CHECK_EQ(sp.get(), wp.lock().get());
// sp.reset();
// CHECK(wp.lock() == nullptr);
//
template <typename T>
std::weak_ptr<T> WeakenPtr(const std::shared_ptr<T>& ptr) {
return std::weak_ptr<T>(ptr);
}
namespace memory_internal {
// ExtractOr<E, O, D>::type evaluates to E<O> if possible. Otherwise, D.
template <template <typename> class Extract, typename Obj, typename Default,
typename>
struct ExtractOr {
using type = Default;
};
template <template <typename> class Extract, typename Obj, typename Default>
struct ExtractOr<Extract, Obj, Default, void_t<Extract<Obj>>> {
using type = Extract<Obj>;
};
template <template <typename> class Extract, typename Obj, typename Default>
using ExtractOrT = typename ExtractOr<Extract, Obj, Default, void>::type;
// Extractors for the features of allocators.
template <typename T>
using GetPointer = typename T::pointer;
template <typename T>
using GetConstPointer = typename T::const_pointer;
template <typename T>
using GetVoidPointer = typename T::void_pointer;
template <typename T>
using GetConstVoidPointer = typename T::const_void_pointer;
template <typename T>
using GetDifferenceType = typename T::difference_type;
template <typename T>
using GetSizeType = typename T::size_type;
template <typename T>
using GetPropagateOnContainerCopyAssignment =
typename T::propagate_on_container_copy_assignment;
template <typename T>
using GetPropagateOnContainerMoveAssignment =
typename T::propagate_on_container_move_assignment;
template <typename T>
using GetPropagateOnContainerSwap = typename T::propagate_on_container_swap;
template <typename T>
using GetIsAlwaysEqual = typename T::is_always_equal;
template <typename T>
struct GetFirstArg;
template <template <typename...> class Class, typename T, typename... Args>
struct GetFirstArg<Class<T, Args...>> {
using type = T;
};
template <typename Ptr, typename = void>
struct ElementType {
using type = typename GetFirstArg<Ptr>::type;
};
template <typename T>
struct ElementType<T, void_t<typename T::element_type>> {
using type = typename T::element_type;
};
template <typename T, typename U>
struct RebindFirstArg;
template <template <typename...> class Class, typename T, typename... Args,
typename U>
struct RebindFirstArg<Class<T, Args...>, U> {
using type = Class<U, Args...>;
};
template <typename T, typename U, typename = void>
struct RebindPtr {
using type = typename RebindFirstArg<T, U>::type;
};
template <typename T, typename U>
struct RebindPtr<T, U, void_t<typename T::template rebind<U>>> {
using type = typename T::template rebind<U>;
};
template <typename T, typename U>
constexpr bool HasRebindAlloc(...) {
return false;
}
template <typename T, typename U>
constexpr bool HasRebindAlloc(typename T::template rebind<U>::other*) {
return true;
}
template <typename T, typename U, bool = HasRebindAlloc<T, U>(nullptr)>
struct RebindAlloc {
using type = typename RebindFirstArg<T, U>::type;
};
template <typename T, typename U>
struct RebindAlloc<T, U, true> {
using type = typename T::template rebind<U>::other;
};
} // namespace memory_internal
// -----------------------------------------------------------------------------
// Class Template: pointer_traits
// -----------------------------------------------------------------------------
//
// An implementation of C++11's std::pointer_traits.
//
// Provided for portability on toolchains that have a working C++11 compiler,
// but the standard library is lacking in C++11 support. For example, some
// version of the Android NDK.
//
template <typename Ptr>
struct pointer_traits {
using pointer = Ptr;
// element_type:
// Ptr::element_type if present. Otherwise T if Ptr is a template
// instantiation Template<T, Args...>
using element_type = typename memory_internal::ElementType<Ptr>::type;
// difference_type:
// Ptr::difference_type if present, otherwise std::ptrdiff_t
using difference_type =
memory_internal::ExtractOrT<memory_internal::GetDifferenceType, Ptr,
std::ptrdiff_t>;
// rebind:
// Ptr::rebind<U> if exists, otherwise Template<U, Args...> if Ptr is a
// template instantiation Template<T, Args...>
template <typename U>
using rebind = typename memory_internal::RebindPtr<Ptr, U>::type;
// pointer_to:
// Calls Ptr::pointer_to(r)
static pointer pointer_to(element_type& r) { // NOLINT(runtime/references)
return Ptr::pointer_to(r);
}
};
// Specialization for T*.
template <typename T>
struct pointer_traits<T*> {
using pointer = T*;
using element_type = T;
using difference_type = std::ptrdiff_t;
template <typename U>
using rebind = U*;
// pointer_to:
// Calls std::addressof(r)
static pointer pointer_to(
element_type& r) noexcept { // NOLINT(runtime/references)
return std::addressof(r);
}
};
// -----------------------------------------------------------------------------
// Class Template: allocator_traits
// -----------------------------------------------------------------------------
//
// A C++11 compatible implementation of C++17's std::allocator_traits.
//
template <typename Alloc>
struct allocator_traits {
using allocator_type = Alloc;
// value_type:
// Alloc::value_type
using value_type = typename Alloc::value_type;
// pointer:
// Alloc::pointer if present, otherwise value_type*
using pointer = memory_internal::ExtractOrT<memory_internal::GetPointer,
Alloc, value_type*>;
// const_pointer:
// Alloc::const_pointer if present, otherwise
// absl::pointer_traits<pointer>::rebind<const value_type>
using const_pointer =
memory_internal::ExtractOrT<memory_internal::GetConstPointer, Alloc,
typename absl::pointer_traits<pointer>::
template rebind<const value_type>>;
// void_pointer:
// Alloc::void_pointer if present, otherwise
// absl::pointer_traits<pointer>::rebind<void>
using void_pointer = memory_internal::ExtractOrT<
memory_internal::GetVoidPointer, Alloc,
typename absl::pointer_traits<pointer>::template rebind<void>>;
// const_void_pointer:
// Alloc::const_void_pointer if present, otherwise
// absl::pointer_traits<pointer>::rebind<const void>
using const_void_pointer = memory_internal::ExtractOrT<
memory_internal::GetConstVoidPointer, Alloc,
typename absl::pointer_traits<pointer>::template rebind<const void>>;
// difference_type:
// Alloc::difference_type if present, otherwise
// absl::pointer_traits<pointer>::difference_type
using difference_type = memory_internal::ExtractOrT<
memory_internal::GetDifferenceType, Alloc,
typename absl::pointer_traits<pointer>::difference_type>;
// size_type:
// Alloc::size_type if present, otherwise
// std::make_unsigned<difference_type>::type
using size_type = memory_internal::ExtractOrT<
memory_internal::GetSizeType, Alloc,
typename std::make_unsigned<difference_type>::type>;
// propagate_on_container_copy_assignment:
// Alloc::propagate_on_container_copy_assignment if present, otherwise
// std::false_type
using propagate_on_container_copy_assignment = memory_internal::ExtractOrT<
memory_internal::GetPropagateOnContainerCopyAssignment, Alloc,
std::false_type>;
// propagate_on_container_move_assignment:
// Alloc::propagate_on_container_move_assignment if present, otherwise
// std::false_type
using propagate_on_container_move_assignment = memory_internal::ExtractOrT<
memory_internal::GetPropagateOnContainerMoveAssignment, Alloc,
std::false_type>;
// propagate_on_container_swap:
// Alloc::propagate_on_container_swap if present, otherwise std::false_type
using propagate_on_container_swap =
memory_internal::ExtractOrT<memory_internal::GetPropagateOnContainerSwap,
Alloc, std::false_type>;
// is_always_equal:
// Alloc::is_always_equal if present, otherwise std::is_empty<Alloc>::type
using is_always_equal =
memory_internal::ExtractOrT<memory_internal::GetIsAlwaysEqual, Alloc,
typename std::is_empty<Alloc>::type>;
// rebind_alloc:
// Alloc::rebind<T>::other if present, otherwise Alloc<T, Args> if this Alloc
// is Alloc<U, Args>
template <typename T>
using rebind_alloc = typename memory_internal::RebindAlloc<Alloc, T>::type;
// rebind_traits:
// absl::allocator_traits<rebind_alloc<T>>
template <typename T>
using rebind_traits = absl::allocator_traits<rebind_alloc<T>>;
// allocate(Alloc& a, size_type n):
// Calls a.allocate(n)
static pointer allocate(Alloc& a, // NOLINT(runtime/references)
size_type n) {
return a.allocate(n);
}
// allocate(Alloc& a, size_type n, const_void_pointer hint):
// Calls a.allocate(n, hint) if possible.
// If not possible, calls a.allocate(n)
static pointer allocate(Alloc& a, size_type n, // NOLINT(runtime/references)
const_void_pointer hint) {
return allocate_impl(0, a, n, hint);
}
// deallocate(Alloc& a, pointer p, size_type n):
// Calls a.deallocate(p, n)
static void deallocate(Alloc& a, pointer p, // NOLINT(runtime/references)
size_type n) {
a.deallocate(p, n);
}
// construct(Alloc& a, T* p, Args&&... args):
// Calls a.construct(p, std::forward<Args>(args)...) if possible.
// If not possible, calls
// ::new (static_cast<void*>(p)) T(std::forward<Args>(args)...)
template <typename T, typename... Args>
static void construct(Alloc& a, T* p, // NOLINT(runtime/references)
Args&&... args) {
construct_impl(0, a, p, std::forward<Args>(args)...);
}
// destroy(Alloc& a, T* p):
// Calls a.destroy(p) if possible. If not possible, calls p->~T().
template <typename T>
static void destroy(Alloc& a, T* p) { // NOLINT(runtime/references)
destroy_impl(0, a, p);
}
// max_size(const Alloc& a):
// Returns a.max_size() if possible. If not possible, returns
// std::numeric_limits<size_type>::max() / sizeof(value_type)
static size_type max_size(const Alloc& a) { return max_size_impl(0, a); }
// select_on_container_copy_construction(const Alloc& a):
// Returns a.select_on_container_copy_construction() if possible.
// If not possible, returns a.
static Alloc select_on_container_copy_construction(const Alloc& a) {
return select_on_container_copy_construction_impl(0, a);
}
private:
template <typename A>
static auto allocate_impl(int, A& a, // NOLINT(runtime/references)
size_type n, const_void_pointer hint)
-> decltype(a.allocate(n, hint)) {
return a.allocate(n, hint);
}
static pointer allocate_impl(char, Alloc& a, // NOLINT(runtime/references)
size_type n, const_void_pointer) {
return a.allocate(n);
}
template <typename A, typename... Args>
static auto construct_impl(int, A& a, // NOLINT(runtime/references)
Args&&... args)
-> decltype(a.construct(std::forward<Args>(args)...)) {
a.construct(std::forward<Args>(args)...);
}
template <typename T, typename... Args>
static void construct_impl(char, Alloc&, T* p, Args&&... args) {
::new (static_cast<void*>(p)) T(std::forward<Args>(args)...);
}
template <typename A, typename T>
static auto destroy_impl(int, A& a, // NOLINT(runtime/references)
T* p) -> decltype(a.destroy(p)) {
a.destroy(p);
}
template <typename T>
static void destroy_impl(char, Alloc&, T* p) {
p->~T();
}
template <typename A>
static auto max_size_impl(int, const A& a) -> decltype(a.max_size()) {
return a.max_size();
}
static size_type max_size_impl(char, const Alloc&) {
return (std::numeric_limits<size_type>::max)() / sizeof(value_type);
}
template <typename A>
static auto select_on_container_copy_construction_impl(int, const A& a)
-> decltype(a.select_on_container_copy_construction()) {
return a.select_on_container_copy_construction();
}
static Alloc select_on_container_copy_construction_impl(char,
const Alloc& a) {
return a;
}
};
namespace memory_internal {
// This template alias transforms Alloc::is_nothrow into a metafunction with
// Alloc as a parameter so it can be used with ExtractOrT<>.
template <typename Alloc>
using GetIsNothrow = typename Alloc::is_nothrow;
} // namespace memory_internal
// ABSL_ALLOCATOR_NOTHROW is a build time configuration macro for user to
// specify whether the default allocation function can throw or never throws.
// If the allocation function never throws, user should define it to a non-zero
// value (e.g. via `-DABSL_ALLOCATOR_NOTHROW`).
// If the allocation function can throw, user should leave it undefined or
// define it to zero.
//
// allocator_is_nothrow<Alloc> is a traits class that derives from
// Alloc::is_nothrow if present, otherwise std::false_type. It's specialized
// for Alloc = std::allocator<T> for any type T according to the state of
// ABSL_ALLOCATOR_NOTHROW.
//
// default_allocator_is_nothrow is a class that derives from std::true_type
// when the default allocator (global operator new) never throws, and
// std::false_type when it can throw. It is a convenience shorthand for writing
// allocator_is_nothrow<std::allocator<T>> (T can be any type).
// NOTE: allocator_is_nothrow<std::allocator<T>> is guaranteed to derive from
// the same type for all T, because users should specialize neither
// allocator_is_nothrow nor std::allocator.
template <typename Alloc>
struct allocator_is_nothrow
: memory_internal::ExtractOrT<memory_internal::GetIsNothrow, Alloc,
std::false_type> {};
#if defined(ABSL_ALLOCATOR_NOTHROW) && ABSL_ALLOCATOR_NOTHROW
template <typename T>
struct allocator_is_nothrow<std::allocator<T>> : std::true_type {};
struct default_allocator_is_nothrow : std::true_type {};
#else
struct default_allocator_is_nothrow : std::false_type {};
#endif
namespace memory_internal {
template <typename Allocator, typename Iterator, typename... Args>
void ConstructRange(Allocator& alloc, Iterator first, Iterator last,
const Args&... args) {
for (Iterator cur = first; cur != last; ++cur) {
ABSL_INTERNAL_TRY {
std::allocator_traits<Allocator>::construct(alloc, std::addressof(*cur),
args...);
}
ABSL_INTERNAL_CATCH_ANY {
while (cur != first) {
--cur;
std::allocator_traits<Allocator>::destroy(alloc, std::addressof(*cur));
}
ABSL_INTERNAL_RETHROW;
}
}
}
template <typename Allocator, typename Iterator, typename InputIterator>
void CopyRange(Allocator& alloc, Iterator destination, InputIterator first,
InputIterator last) {
for (Iterator cur = destination; first != last;
static_cast<void>(++cur), static_cast<void>(++first)) {
ABSL_INTERNAL_TRY {
std::allocator_traits<Allocator>::construct(alloc, std::addressof(*cur),
*first);
}
ABSL_INTERNAL_CATCH_ANY {
while (cur != destination) {
--cur;
std::allocator_traits<Allocator>::destroy(alloc, std::addressof(*cur));
}
ABSL_INTERNAL_RETHROW;
}
}
}
} // namespace memory_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_MEMORY_MEMORY_H_