[base] Replace base::Optional with Abseil
Change base::Optional to an alias of absl::optional. Eventually we should remove it entirely. Bug: v8:11006 Change-Id: I687d44cc7e7cd0a49a84bcc207231eb6808eef2d Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2476318 Commit-Queue: Leszek Swirski <leszeks@chromium.org> Reviewed-by: Michael Lippautz <mlippautz@chromium.org> Cr-Commit-Position: refs/heads/main@{#76913}
This commit is contained in:
Leszek Swirski
V8 LUCI CQ
parent
b584f27372
commit
f2e25f8a09
2
BUILD.gn
2
BUILD.gn
@ -4909,6 +4909,8 @@ v8_component("v8_libbase") {
|
||||
|
||||
deps = [ ":v8_config_headers" ]
|
||||
|
||||
public_deps = [ ":v8_abseil" ]
|
||||
|
||||
data = []
|
||||
|
||||
data_deps = []
|
||||
|
||||
@ -1,880 +1,23 @@
|
||||
// Copyright 2016 The Chromium Authors. All rights reserved.
|
||||
// Copyright 2017 the V8 project authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style license that can be
|
||||
// found in the LICENSE file.
|
||||
|
||||
// This file is a clone of "base/optional.h" in chromium.
|
||||
// Keep in sync, especially when fixing bugs.
|
||||
// Copyright 2017 the V8 project authors. All rights reserved.
|
||||
|
||||
#ifndef V8_BASE_OPTIONAL_H_
|
||||
#define V8_BASE_OPTIONAL_H_
|
||||
|
||||
#include <type_traits>
|
||||
#include <utility>
|
||||
|
||||
#include "src/base/logging.h"
|
||||
#include "absl/types/optional.h"
|
||||
|
||||
namespace v8 {
|
||||
namespace base {
|
||||
|
||||
// Specification:
|
||||
// http://en.cppreference.com/w/cpp/utility/optional/in_place_t
|
||||
struct in_place_t {};
|
||||
|
||||
// Specification:
|
||||
// http://en.cppreference.com/w/cpp/utility/optional/nullopt_t
|
||||
struct nullopt_t {
|
||||
constexpr explicit nullopt_t(int) {}
|
||||
};
|
||||
|
||||
// Specification:
|
||||
// http://en.cppreference.com/w/cpp/utility/optional/in_place
|
||||
constexpr in_place_t in_place = {};
|
||||
|
||||
// Specification:
|
||||
// http://en.cppreference.com/w/cpp/utility/optional/nullopt
|
||||
constexpr nullopt_t nullopt(0);
|
||||
|
||||
// Forward declaration, which is referred by following helpers.
|
||||
using absl::bad_optional_access;
|
||||
template <typename T>
|
||||
class Optional;
|
||||
|
||||
namespace internal {
|
||||
|
||||
template <typename T, bool = std::is_trivially_destructible<T>::value>
|
||||
struct OptionalStorageBase {
|
||||
// Initializing |empty_| here instead of using default member initializing
|
||||
// to avoid errors in g++ 4.8.
|
||||
constexpr OptionalStorageBase() : empty_('\0') {}
|
||||
|
||||
template <class... Args>
|
||||
constexpr explicit OptionalStorageBase(in_place_t, Args&&... args)
|
||||
: is_populated_(true), value_(std::forward<Args>(args)...) {}
|
||||
|
||||
// When T is not trivially destructible we must call its
|
||||
// destructor before deallocating its memory.
|
||||
// Note that this hides the (implicitly declared) move constructor, which
|
||||
// would be used for constexpr move constructor in OptionalStorage<T>.
|
||||
// It is needed iff T is trivially move constructible. However, the current
|
||||
// is_trivially_{copy,move}_constructible implementation requires
|
||||
// is_trivially_destructible (which looks a bug, cf:
|
||||
// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51452 and
|
||||
// http://cplusplus.github.io/LWG/lwg-active.html#2116), so it is not
|
||||
// necessary for this case at the moment. Please see also the destructor
|
||||
// comment in "is_trivially_destructible = true" specialization below.
|
||||
~OptionalStorageBase() {
|
||||
if (is_populated_) value_.~T();
|
||||
}
|
||||
|
||||
template <class... Args>
|
||||
void Init(Args&&... args) {
|
||||
DCHECK(!is_populated_);
|
||||
::new (&value_) T(std::forward<Args>(args)...);
|
||||
is_populated_ = true;
|
||||
}
|
||||
|
||||
bool is_populated_ = false;
|
||||
union {
|
||||
// |empty_| exists so that the union will always be initialized, even when
|
||||
// it doesn't contain a value. Union members must be initialized for the
|
||||
// constructor to be 'constexpr'.
|
||||
char empty_;
|
||||
T value_;
|
||||
};
|
||||
};
|
||||
|
||||
template <typename T>
|
||||
struct OptionalStorageBase<T, true /* trivially destructible */> {
|
||||
// Initializing |empty_| here instead of using default member initializing
|
||||
// to avoid errors in g++ 4.8.
|
||||
constexpr OptionalStorageBase() : empty_('\0') {}
|
||||
|
||||
template <class... Args>
|
||||
constexpr explicit OptionalStorageBase(in_place_t, Args&&... args)
|
||||
: is_populated_(true), value_(std::forward<Args>(args)...) {}
|
||||
|
||||
// When T is trivially destructible (i.e. its destructor does nothing) there
|
||||
// is no need to call it. Implicitly defined destructor is trivial, because
|
||||
// both members (bool and union containing only variants which are trivially
|
||||
// destructible) are trivially destructible.
|
||||
// Explicitly-defaulted destructor is also trivial, but do not use it here,
|
||||
// because it hides the implicit move constructor. It is needed to implement
|
||||
// constexpr move constructor in OptionalStorage iff T is trivially move
|
||||
// constructible. Note that, if T is trivially move constructible, the move
|
||||
// constructor of OptionalStorageBase<T> is also implicitly defined and it is
|
||||
// trivially move constructor. If T is not trivially move constructible,
|
||||
// "not declaring move constructor without destructor declaration" here means
|
||||
// "delete move constructor", which works because any move constructor of
|
||||
// OptionalStorage will not refer to it in that case.
|
||||
|
||||
template <class... Args>
|
||||
void Init(Args&&... args) {
|
||||
DCHECK(!is_populated_);
|
||||
::new (&value_) T(std::forward<Args>(args)...);
|
||||
is_populated_ = true;
|
||||
}
|
||||
|
||||
bool is_populated_ = false;
|
||||
union {
|
||||
// |empty_| exists so that the union will always be initialized, even when
|
||||
// it doesn't contain a value. Union members must be initialized for the
|
||||
// constructor to be 'constexpr'.
|
||||
char empty_;
|
||||
T value_;
|
||||
};
|
||||
};
|
||||
|
||||
// Implement conditional constexpr copy and move constructors. These are
|
||||
// constexpr if is_trivially_{copy,move}_constructible<T>::value is true
|
||||
// respectively. If each is true, the corresponding constructor is defined as
|
||||
// "= default;", which generates a constexpr constructor (In this case,
|
||||
// the condition of constexpr-ness is satisfied because the base class also has
|
||||
// compiler generated constexpr {copy,move} constructors). Note that
|
||||
// placement-new is prohibited in constexpr.
|
||||
template <typename T, bool = std::is_trivially_copy_constructible<T>::value,
|
||||
bool = std::is_trivially_move_constructible<T>::value>
|
||||
struct OptionalStorage : OptionalStorageBase<T> {
|
||||
// This is no trivially {copy,move} constructible case. Other cases are
|
||||
// defined below as specializations.
|
||||
|
||||
// Accessing the members of template base class requires explicit
|
||||
// declaration.
|
||||
using OptionalStorageBase<T>::is_populated_;
|
||||
using OptionalStorageBase<T>::value_;
|
||||
using OptionalStorageBase<T>::Init;
|
||||
|
||||
// Inherit constructors (specifically, the in_place constructor).
|
||||
using OptionalStorageBase<T>::OptionalStorageBase;
|
||||
|
||||
// User defined constructor deletes the default constructor.
|
||||
// Define it explicitly.
|
||||
OptionalStorage() = default;
|
||||
|
||||
OptionalStorage(const OptionalStorage& other) V8_NOEXCEPT {
|
||||
if (other.is_populated_) Init(other.value_);
|
||||
}
|
||||
|
||||
OptionalStorage(OptionalStorage&& other) V8_NOEXCEPT {
|
||||
if (other.is_populated_) Init(std::move(other.value_));
|
||||
}
|
||||
};
|
||||
|
||||
template <typename T>
|
||||
struct OptionalStorage<T, true /* trivially copy constructible */,
|
||||
false /* trivially move constructible */>
|
||||
: OptionalStorageBase<T> {
|
||||
using OptionalStorageBase<T>::is_populated_;
|
||||
using OptionalStorageBase<T>::value_;
|
||||
using OptionalStorageBase<T>::Init;
|
||||
using OptionalStorageBase<T>::OptionalStorageBase;
|
||||
|
||||
OptionalStorage() = default;
|
||||
OptionalStorage(const OptionalStorage& other) V8_NOEXCEPT = default;
|
||||
|
||||
OptionalStorage(OptionalStorage&& other) V8_NOEXCEPT {
|
||||
if (other.is_populated_) Init(std::move(other.value_));
|
||||
}
|
||||
};
|
||||
|
||||
template <typename T>
|
||||
struct OptionalStorage<T, false /* trivially copy constructible */,
|
||||
true /* trivially move constructible */>
|
||||
: OptionalStorageBase<T> {
|
||||
using OptionalStorageBase<T>::is_populated_;
|
||||
using OptionalStorageBase<T>::value_;
|
||||
using OptionalStorageBase<T>::Init;
|
||||
using OptionalStorageBase<T>::OptionalStorageBase;
|
||||
|
||||
OptionalStorage() = default;
|
||||
OptionalStorage(OptionalStorage&& other) V8_NOEXCEPT = default;
|
||||
|
||||
OptionalStorage(const OptionalStorage& other) V8_NOEXCEPT {
|
||||
if (other.is_populated_) Init(other.value_);
|
||||
}
|
||||
};
|
||||
|
||||
template <typename T>
|
||||
struct OptionalStorage<T, true /* trivially copy constructible */,
|
||||
true /* trivially move constructible */>
|
||||
: OptionalStorageBase<T> {
|
||||
// If both trivially {copy,move} constructible are true, it is not necessary
|
||||
// to use user-defined constructors. So, just inheriting constructors
|
||||
// from the base class works.
|
||||
using OptionalStorageBase<T>::OptionalStorageBase;
|
||||
};
|
||||
|
||||
// Base class to support conditionally usable copy-/move- constructors
|
||||
// and assign operators.
|
||||
template <typename T>
|
||||
class OptionalBase {
|
||||
// This class provides implementation rather than public API, so everything
|
||||
// should be hidden. Often we use composition, but we cannot in this case
|
||||
// because of C++ language restriction.
|
||||
protected:
|
||||
constexpr OptionalBase() = default;
|
||||
constexpr OptionalBase(const OptionalBase& other) V8_NOEXCEPT = default;
|
||||
constexpr OptionalBase(OptionalBase&& other) V8_NOEXCEPT = default;
|
||||
|
||||
template <class... Args>
|
||||
constexpr explicit OptionalBase(in_place_t, Args&&... args)
|
||||
: storage_(in_place, std::forward<Args>(args)...) {}
|
||||
|
||||
// Implementation of converting constructors.
|
||||
template <typename U>
|
||||
explicit OptionalBase(const OptionalBase<U>& other) V8_NOEXCEPT {
|
||||
if (other.storage_.is_populated_) storage_.Init(other.storage_.value_);
|
||||
}
|
||||
|
||||
template <typename U>
|
||||
explicit OptionalBase(OptionalBase<U>&& other) V8_NOEXCEPT {
|
||||
if (other.storage_.is_populated_)
|
||||
storage_.Init(std::move(other.storage_.value_));
|
||||
}
|
||||
|
||||
~OptionalBase() = default;
|
||||
|
||||
OptionalBase& operator=(const OptionalBase& other) V8_NOEXCEPT {
|
||||
CopyAssign(other);
|
||||
return *this;
|
||||
}
|
||||
|
||||
OptionalBase& operator=(OptionalBase&& other) V8_NOEXCEPT {
|
||||
MoveAssign(std::move(other));
|
||||
return *this;
|
||||
}
|
||||
|
||||
template <typename U>
|
||||
void CopyAssign(const OptionalBase<U>& other) {
|
||||
if (other.storage_.is_populated_)
|
||||
InitOrAssign(other.storage_.value_);
|
||||
else
|
||||
FreeIfNeeded();
|
||||
}
|
||||
|
||||
template <typename U>
|
||||
void MoveAssign(OptionalBase<U>&& other) {
|
||||
if (other.storage_.is_populated_)
|
||||
InitOrAssign(std::move(other.storage_.value_));
|
||||
else
|
||||
FreeIfNeeded();
|
||||
}
|
||||
|
||||
template <typename U>
|
||||
void InitOrAssign(U&& value) {
|
||||
if (storage_.is_populated_)
|
||||
storage_.value_ = std::forward<U>(value);
|
||||
else
|
||||
storage_.Init(std::forward<U>(value));
|
||||
}
|
||||
|
||||
void FreeIfNeeded() {
|
||||
if (!storage_.is_populated_) return;
|
||||
storage_.value_.~T();
|
||||
storage_.is_populated_ = false;
|
||||
}
|
||||
|
||||
// For implementing conversion, allow access to other typed OptionalBase
|
||||
// class.
|
||||
template <typename U>
|
||||
friend class OptionalBase;
|
||||
|
||||
OptionalStorage<T> storage_;
|
||||
};
|
||||
|
||||
// The following {Copy,Move}{Constructible,Assignable} structs are helpers to
|
||||
// implement constructor/assign-operator overloading. Specifically, if T is
|
||||
// is not movable but copyable, Optional<T>'s move constructor should not
|
||||
// participate in overload resolution. This inheritance trick implements that.
|
||||
template <bool is_copy_constructible>
|
||||
struct CopyConstructible {};
|
||||
|
||||
template <>
|
||||
struct CopyConstructible<false> {
|
||||
constexpr CopyConstructible() = default;
|
||||
constexpr CopyConstructible(const CopyConstructible&) V8_NOEXCEPT = delete;
|
||||
constexpr CopyConstructible(CopyConstructible&&) V8_NOEXCEPT = default;
|
||||
CopyConstructible& operator=(const CopyConstructible&) V8_NOEXCEPT = default;
|
||||
CopyConstructible& operator=(CopyConstructible&&) V8_NOEXCEPT = default;
|
||||
};
|
||||
|
||||
template <bool is_move_constructible>
|
||||
struct MoveConstructible {};
|
||||
|
||||
template <>
|
||||
struct MoveConstructible<false> {
|
||||
constexpr MoveConstructible() = default;
|
||||
constexpr MoveConstructible(const MoveConstructible&) V8_NOEXCEPT = default;
|
||||
constexpr MoveConstructible(MoveConstructible&&) V8_NOEXCEPT = delete;
|
||||
MoveConstructible& operator=(const MoveConstructible&) V8_NOEXCEPT = default;
|
||||
MoveConstructible& operator=(MoveConstructible&&) V8_NOEXCEPT = default;
|
||||
};
|
||||
|
||||
template <bool is_copy_assignable>
|
||||
struct CopyAssignable {};
|
||||
|
||||
template <>
|
||||
struct CopyAssignable<false> {
|
||||
constexpr CopyAssignable() = default;
|
||||
constexpr CopyAssignable(const CopyAssignable&) V8_NOEXCEPT = default;
|
||||
constexpr CopyAssignable(CopyAssignable&&) V8_NOEXCEPT = default;
|
||||
CopyAssignable& operator=(const CopyAssignable&) V8_NOEXCEPT = delete;
|
||||
CopyAssignable& operator=(CopyAssignable&&) V8_NOEXCEPT = default;
|
||||
};
|
||||
|
||||
template <bool is_move_assignable>
|
||||
struct MoveAssignable {};
|
||||
|
||||
template <>
|
||||
struct MoveAssignable<false> {
|
||||
constexpr MoveAssignable() = default;
|
||||
constexpr MoveAssignable(const MoveAssignable&) V8_NOEXCEPT = default;
|
||||
constexpr MoveAssignable(MoveAssignable&&) V8_NOEXCEPT = default;
|
||||
MoveAssignable& operator=(const MoveAssignable&) V8_NOEXCEPT = default;
|
||||
MoveAssignable& operator=(MoveAssignable&&) V8_NOEXCEPT = delete;
|
||||
};
|
||||
|
||||
// Helper to conditionally enable converting constructors and assign operators.
|
||||
template <typename T, typename U>
|
||||
struct IsConvertibleFromOptional
|
||||
: std::integral_constant<
|
||||
bool, std::is_constructible<T, Optional<U>&>::value ||
|
||||
std::is_constructible<T, const Optional<U>&>::value ||
|
||||
std::is_constructible<T, Optional<U>&&>::value ||
|
||||
std::is_constructible<T, const Optional<U>&&>::value ||
|
||||
std::is_convertible<Optional<U>&, T>::value ||
|
||||
std::is_convertible<const Optional<U>&, T>::value ||
|
||||
std::is_convertible<Optional<U>&&, T>::value ||
|
||||
std::is_convertible<const Optional<U>&&, T>::value> {};
|
||||
|
||||
template <typename T, typename U>
|
||||
struct IsAssignableFromOptional
|
||||
: std::integral_constant<
|
||||
bool, IsConvertibleFromOptional<T, U>::value ||
|
||||
std::is_assignable<T&, Optional<U>&>::value ||
|
||||
std::is_assignable<T&, const Optional<U>&>::value ||
|
||||
std::is_assignable<T&, Optional<U>&&>::value ||
|
||||
std::is_assignable<T&, const Optional<U>&&>::value> {};
|
||||
|
||||
// Forward compatibility for C++17.
|
||||
// Introduce one more deeper nested namespace to avoid leaking using std::swap.
|
||||
namespace swappable_impl {
|
||||
using std::swap;
|
||||
|
||||
struct IsSwappableImpl {
|
||||
// Tests if swap can be called. Check<T&>(0) returns true_type iff swap
|
||||
// is available for T. Otherwise, Check's overload resolution falls back
|
||||
// to Check(...) declared below thanks to SFINAE, so returns false_type.
|
||||
template <typename T>
|
||||
static auto Check(int i)
|
||||
-> decltype(swap(std::declval<T>(), std::declval<T>()), std::true_type());
|
||||
|
||||
template <typename T>
|
||||
static std::false_type Check(...);
|
||||
};
|
||||
} // namespace swappable_impl
|
||||
|
||||
template <typename T>
|
||||
struct IsSwappable : decltype(swappable_impl::IsSwappableImpl::Check<T&>(0)) {};
|
||||
|
||||
// Forward compatibility for C++20.
|
||||
template <typename T>
|
||||
using RemoveCvRefT =
|
||||
typename std::remove_cv<typename std::remove_reference<T>::type>::type;
|
||||
|
||||
} // namespace internal
|
||||
|
||||
// On Windows, by default, empty-base class optimization does not work,
|
||||
// which means even if the base class is empty struct, it still consumes one
|
||||
// byte for its body. __declspec(empty_bases) enables the optimization.
|
||||
// cf)
|
||||
// https://blogs.msdn.microsoft.com/vcblog/2016/03/30/optimizing-the-layout-of-empty-base-classes-in-vs2015-update-2-3/
|
||||
#ifdef OS_WIN
|
||||
#define OPTIONAL_DECLSPEC_EMPTY_BASES __declspec(empty_bases)
|
||||
#else
|
||||
#define OPTIONAL_DECLSPEC_EMPTY_BASES
|
||||
#endif
|
||||
|
||||
// base::Optional is a Chromium version of the C++17 optional class:
|
||||
// std::optional documentation:
|
||||
// http://en.cppreference.com/w/cpp/utility/optional
|
||||
// Chromium documentation:
|
||||
// https://chromium.googlesource.com/chromium/src/+/master/docs/optional.md
|
||||
//
|
||||
// These are the differences between the specification and the implementation:
|
||||
// - Constructors do not use 'constexpr' as it is a C++14 extension.
|
||||
// - 'constexpr' might be missing in some places for reasons specified locally.
|
||||
// - No exceptions are thrown, because they are banned from Chromium.
|
||||
// All copy/move constructors or assignment operators are marked V8_NOEXCEPT.
|
||||
// - All the non-members are in the 'base' namespace instead of 'std'.
|
||||
//
|
||||
// Note that T cannot have a constructor T(Optional<T>) etc. Optional<T> checks
|
||||
// T's constructor (specifically via IsConvertibleFromOptional), and in the
|
||||
// check whether T can be constructible from Optional<T>, which is recursive
|
||||
// so it does not work. As of Feb 2018, std::optional C++17 implementation in
|
||||
// both clang and gcc has same limitation. MSVC SFINAE looks to have different
|
||||
// behavior, but anyway it reports an error, too.
|
||||
template <typename T>
|
||||
class OPTIONAL_DECLSPEC_EMPTY_BASES Optional
|
||||
: public internal::OptionalBase<T>,
|
||||
public internal::CopyConstructible<std::is_copy_constructible<T>::value>,
|
||||
public internal::MoveConstructible<std::is_move_constructible<T>::value>,
|
||||
public internal::CopyAssignable<std::is_copy_constructible<T>::value &&
|
||||
std::is_copy_assignable<T>::value>,
|
||||
public internal::MoveAssignable<std::is_move_constructible<T>::value &&
|
||||
std::is_move_assignable<T>::value> {
|
||||
public:
|
||||
#undef OPTIONAL_DECLSPEC_EMPTY_BASES
|
||||
using value_type = T;
|
||||
|
||||
// Defer default/copy/move constructor implementation to OptionalBase.
|
||||
constexpr Optional() = default;
|
||||
constexpr Optional(const Optional& other) V8_NOEXCEPT = default;
|
||||
constexpr Optional(Optional&& other) V8_NOEXCEPT = default;
|
||||
|
||||
constexpr Optional(nullopt_t) {} // NOLINT(runtime/explicit)
|
||||
|
||||
// Converting copy constructor. "explicit" only if
|
||||
// std::is_convertible<const U&, T>::value is false. It is implemented by
|
||||
// declaring two almost same constructors, but that condition in enable_if
|
||||
// is different, so that either one is chosen, thanks to SFINAE.
|
||||
template <typename U,
|
||||
typename std::enable_if<
|
||||
std::is_constructible<T, const U&>::value &&
|
||||
!internal::IsConvertibleFromOptional<T, U>::value &&
|
||||
std::is_convertible<const U&, T>::value,
|
||||
bool>::type = false>
|
||||
Optional(const Optional<U>& other) V8_NOEXCEPT
|
||||
: internal::OptionalBase<T>(other) {}
|
||||
|
||||
template <typename U,
|
||||
typename std::enable_if<
|
||||
std::is_constructible<T, const U&>::value &&
|
||||
!internal::IsConvertibleFromOptional<T, U>::value &&
|
||||
!std::is_convertible<const U&, T>::value,
|
||||
bool>::type = false>
|
||||
explicit Optional(const Optional<U>& other) V8_NOEXCEPT
|
||||
: internal::OptionalBase<T>(other) {}
|
||||
|
||||
// Converting move constructor. Similar to converting copy constructor,
|
||||
// declaring two (explicit and non-explicit) constructors.
|
||||
template <typename U,
|
||||
typename std::enable_if<
|
||||
std::is_constructible<T, U&&>::value &&
|
||||
!internal::IsConvertibleFromOptional<T, U>::value &&
|
||||
std::is_convertible<U&&, T>::value,
|
||||
bool>::type = false>
|
||||
Optional(Optional<U>&& other) V8_NOEXCEPT
|
||||
: internal::OptionalBase<T>(std::move(other)) {}
|
||||
|
||||
template <typename U,
|
||||
typename std::enable_if<
|
||||
std::is_constructible<T, U&&>::value &&
|
||||
!internal::IsConvertibleFromOptional<T, U>::value &&
|
||||
!std::is_convertible<U&&, T>::value,
|
||||
bool>::type = false>
|
||||
explicit Optional(Optional<U>&& other) V8_NOEXCEPT
|
||||
: internal::OptionalBase<T>(std::move(other)) {}
|
||||
|
||||
template <class... Args>
|
||||
constexpr explicit Optional(in_place_t, Args&&... args)
|
||||
: internal::OptionalBase<T>(in_place, std::forward<Args>(args)...) {}
|
||||
|
||||
template <class U, class... Args,
|
||||
class = typename std::enable_if<std::is_constructible<
|
||||
value_type, std::initializer_list<U>&, Args...>::value>::type>
|
||||
constexpr explicit Optional(in_place_t, std::initializer_list<U> il,
|
||||
Args&&... args)
|
||||
: internal::OptionalBase<T>(in_place, il, std::forward<Args>(args)...) {}
|
||||
|
||||
// Forward value constructor. Similar to converting constructors,
|
||||
// conditionally explicit.
|
||||
template <
|
||||
typename U = value_type,
|
||||
typename std::enable_if<
|
||||
std::is_constructible<T, U&&>::value &&
|
||||
!std::is_same<internal::RemoveCvRefT<U>, in_place_t>::value &&
|
||||
!std::is_same<internal::RemoveCvRefT<U>, Optional<T>>::value &&
|
||||
std::is_convertible<U&&, T>::value,
|
||||
bool>::type = false>
|
||||
constexpr Optional(U&& value) // NOLINT(runtime/explicit)
|
||||
: internal::OptionalBase<T>(in_place, std::forward<U>(value)) {}
|
||||
|
||||
template <
|
||||
typename U = value_type,
|
||||
typename std::enable_if<
|
||||
std::is_constructible<T, U&&>::value &&
|
||||
!std::is_same<internal::RemoveCvRefT<U>, in_place_t>::value &&
|
||||
!std::is_same<internal::RemoveCvRefT<U>, Optional<T>>::value &&
|
||||
!std::is_convertible<U&&, T>::value,
|
||||
bool>::type = false>
|
||||
constexpr explicit Optional(U&& value)
|
||||
: internal::OptionalBase<T>(in_place, std::forward<U>(value)) {}
|
||||
|
||||
~Optional() = default;
|
||||
|
||||
// Defer copy-/move- assign operator implementation to OptionalBase.
|
||||
Optional& operator=(const Optional& other) V8_NOEXCEPT = default;
|
||||
Optional& operator=(Optional&& other) V8_NOEXCEPT = default;
|
||||
|
||||
Optional& operator=(nullopt_t) {
|
||||
FreeIfNeeded();
|
||||
return *this;
|
||||
}
|
||||
|
||||
// Perfect-forwarded assignment.
|
||||
template <typename U>
|
||||
typename std::enable_if<
|
||||
!std::is_same<internal::RemoveCvRefT<U>, Optional<T>>::value &&
|
||||
std::is_constructible<T, U>::value &&
|
||||
std::is_assignable<T&, U>::value &&
|
||||
(!std::is_scalar<T>::value ||
|
||||
!std::is_same<typename std::decay<U>::type, T>::value),
|
||||
Optional&>::type
|
||||
operator=(U&& value) V8_NOEXCEPT {
|
||||
InitOrAssign(std::forward<U>(value));
|
||||
return *this;
|
||||
}
|
||||
|
||||
// Copy assign the state of other.
|
||||
template <typename U>
|
||||
typename std::enable_if<!internal::IsAssignableFromOptional<T, U>::value &&
|
||||
std::is_constructible<T, const U&>::value &&
|
||||
std::is_assignable<T&, const U&>::value,
|
||||
Optional&>::type
|
||||
operator=(const Optional<U>& other) V8_NOEXCEPT {
|
||||
CopyAssign(other);
|
||||
return *this;
|
||||
}
|
||||
|
||||
// Move assign the state of other.
|
||||
template <typename U>
|
||||
typename std::enable_if<!internal::IsAssignableFromOptional<T, U>::value &&
|
||||
std::is_constructible<T, U>::value &&
|
||||
std::is_assignable<T&, U>::value,
|
||||
Optional&>::type
|
||||
operator=(Optional<U>&& other) V8_NOEXCEPT {
|
||||
MoveAssign(std::move(other));
|
||||
return *this;
|
||||
}
|
||||
|
||||
constexpr const T* operator->() const {
|
||||
DCHECK(storage_.is_populated_);
|
||||
return &storage_.value_;
|
||||
}
|
||||
|
||||
constexpr T* operator->() {
|
||||
DCHECK(storage_.is_populated_);
|
||||
return &storage_.value_;
|
||||
}
|
||||
|
||||
constexpr const T& operator*() const& {
|
||||
DCHECK(storage_.is_populated_);
|
||||
return storage_.value_;
|
||||
}
|
||||
|
||||
constexpr T& operator*() & {
|
||||
DCHECK(storage_.is_populated_);
|
||||
return storage_.value_;
|
||||
}
|
||||
|
||||
constexpr const T&& operator*() const&& {
|
||||
DCHECK(storage_.is_populated_);
|
||||
return std::move(storage_.value_);
|
||||
}
|
||||
|
||||
constexpr T&& operator*() && {
|
||||
DCHECK(storage_.is_populated_);
|
||||
return std::move(storage_.value_);
|
||||
}
|
||||
|
||||
constexpr explicit operator bool() const { return storage_.is_populated_; }
|
||||
|
||||
constexpr bool has_value() const { return storage_.is_populated_; }
|
||||
|
||||
T& value() & {
|
||||
CHECK(storage_.is_populated_);
|
||||
return storage_.value_;
|
||||
}
|
||||
|
||||
const T& value() const & {
|
||||
CHECK(storage_.is_populated_);
|
||||
return storage_.value_;
|
||||
}
|
||||
|
||||
T&& value() && {
|
||||
CHECK(storage_.is_populated_);
|
||||
return std::move(storage_.value_);
|
||||
}
|
||||
|
||||
const T&& value() const && {
|
||||
CHECK(storage_.is_populated_);
|
||||
return std::move(storage_.value_);
|
||||
}
|
||||
|
||||
template <class U>
|
||||
constexpr T value_or(U&& default_value) const & {
|
||||
// TODO(mlamouri): add the following assert when possible:
|
||||
// static_assert(std::is_copy_constructible<T>::value,
|
||||
// "T must be copy constructible");
|
||||
static_assert(std::is_convertible<U, T>::value,
|
||||
"U must be convertible to T");
|
||||
return storage_.is_populated_
|
||||
? storage_.value_
|
||||
: static_cast<T>(std::forward<U>(default_value));
|
||||
}
|
||||
|
||||
template <class U>
|
||||
T value_or(U&& default_value) && {
|
||||
// TODO(mlamouri): add the following assert when possible:
|
||||
// static_assert(std::is_move_constructible<T>::value,
|
||||
// "T must be move constructible");
|
||||
static_assert(std::is_convertible<U, T>::value,
|
||||
"U must be convertible to T");
|
||||
return storage_.is_populated_
|
||||
? std::move(storage_.value_)
|
||||
: static_cast<T>(std::forward<U>(default_value));
|
||||
}
|
||||
|
||||
void swap(Optional& other) {
|
||||
if (!storage_.is_populated_ && !other.storage_.is_populated_) return;
|
||||
|
||||
if (storage_.is_populated_ != other.storage_.is_populated_) {
|
||||
if (storage_.is_populated_) {
|
||||
other.storage_.Init(std::move(storage_.value_));
|
||||
FreeIfNeeded();
|
||||
} else {
|
||||
storage_.Init(std::move(other.storage_.value_));
|
||||
other.FreeIfNeeded();
|
||||
}
|
||||
return;
|
||||
}
|
||||
|
||||
DCHECK(storage_.is_populated_ && other.storage_.is_populated_);
|
||||
using std::swap;
|
||||
swap(**this, *other);
|
||||
}
|
||||
|
||||
void reset() { FreeIfNeeded(); }
|
||||
|
||||
template <class... Args>
|
||||
T& emplace(Args&&... args) {
|
||||
FreeIfNeeded();
|
||||
storage_.Init(std::forward<Args>(args)...);
|
||||
return storage_.value_;
|
||||
}
|
||||
|
||||
template <class U, class... Args>
|
||||
typename std::enable_if<
|
||||
std::is_constructible<T, std::initializer_list<U>&, Args&&...>::value,
|
||||
T&>::type
|
||||
emplace(std::initializer_list<U> il, Args&&... args) {
|
||||
FreeIfNeeded();
|
||||
storage_.Init(il, std::forward<Args>(args)...);
|
||||
return storage_.value_;
|
||||
}
|
||||
|
||||
private:
|
||||
// Accessing template base class's protected member needs explicit
|
||||
// declaration to do so.
|
||||
using internal::OptionalBase<T>::CopyAssign;
|
||||
using internal::OptionalBase<T>::FreeIfNeeded;
|
||||
using internal::OptionalBase<T>::InitOrAssign;
|
||||
using internal::OptionalBase<T>::MoveAssign;
|
||||
using internal::OptionalBase<T>::storage_;
|
||||
};
|
||||
|
||||
// Here after defines comparation operators. The definition follows
|
||||
// http://en.cppreference.com/w/cpp/utility/optional/operator_cmp
|
||||
// while bool() casting is replaced by has_value() to meet the chromium
|
||||
// style guide.
|
||||
template <class T, class U>
|
||||
bool operator==(const Optional<T>& lhs, const Optional<U>& rhs) {
|
||||
if (lhs.has_value() != rhs.has_value()) return false;
|
||||
if (!lhs.has_value()) return true;
|
||||
return *lhs == *rhs;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
bool operator!=(const Optional<T>& lhs, const Optional<U>& rhs) {
|
||||
if (lhs.has_value() != rhs.has_value()) return true;
|
||||
if (!lhs.has_value()) return false;
|
||||
return *lhs != *rhs;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
bool operator<(const Optional<T>& lhs, const Optional<U>& rhs) {
|
||||
if (!rhs.has_value()) return false;
|
||||
if (!lhs.has_value()) return true;
|
||||
return *lhs < *rhs;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
bool operator<=(const Optional<T>& lhs, const Optional<U>& rhs) {
|
||||
if (!lhs.has_value()) return true;
|
||||
if (!rhs.has_value()) return false;
|
||||
return *lhs <= *rhs;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
bool operator>(const Optional<T>& lhs, const Optional<U>& rhs) {
|
||||
if (!lhs.has_value()) return false;
|
||||
if (!rhs.has_value()) return true;
|
||||
return *lhs > *rhs;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
bool operator>=(const Optional<T>& lhs, const Optional<U>& rhs) {
|
||||
if (!rhs.has_value()) return true;
|
||||
if (!lhs.has_value()) return false;
|
||||
return *lhs >= *rhs;
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator==(const Optional<T>& opt, nullopt_t) {
|
||||
return !opt;
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator==(nullopt_t, const Optional<T>& opt) {
|
||||
return !opt;
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator!=(const Optional<T>& opt, nullopt_t) {
|
||||
return opt.has_value();
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator!=(nullopt_t, const Optional<T>& opt) {
|
||||
return opt.has_value();
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator<(const Optional<T>& opt, nullopt_t) {
|
||||
return false;
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator<(nullopt_t, const Optional<T>& opt) {
|
||||
return opt.has_value();
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator<=(const Optional<T>& opt, nullopt_t) {
|
||||
return !opt;
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator<=(nullopt_t, const Optional<T>& opt) {
|
||||
return true;
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator>(const Optional<T>& opt, nullopt_t) {
|
||||
return opt.has_value();
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator>(nullopt_t, const Optional<T>& opt) {
|
||||
return false;
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator>=(const Optional<T>& opt, nullopt_t) {
|
||||
return true;
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr bool operator>=(nullopt_t, const Optional<T>& opt) {
|
||||
return !opt;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator==(const Optional<T>& opt, const U& value) {
|
||||
return opt.has_value() ? *opt == value : false;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator==(const U& value, const Optional<T>& opt) {
|
||||
return opt.has_value() ? value == *opt : false;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator!=(const Optional<T>& opt, const U& value) {
|
||||
return opt.has_value() ? *opt != value : true;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator!=(const U& value, const Optional<T>& opt) {
|
||||
return opt.has_value() ? value != *opt : true;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator<(const Optional<T>& opt, const U& value) {
|
||||
return opt.has_value() ? *opt < value : true;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator<(const U& value, const Optional<T>& opt) {
|
||||
return opt.has_value() ? value < *opt : false;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator<=(const Optional<T>& opt, const U& value) {
|
||||
return opt.has_value() ? *opt <= value : true;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator<=(const U& value, const Optional<T>& opt) {
|
||||
return opt.has_value() ? value <= *opt : false;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator>(const Optional<T>& opt, const U& value) {
|
||||
return opt.has_value() ? *opt > value : false;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator>(const U& value, const Optional<T>& opt) {
|
||||
return opt.has_value() ? value > *opt : true;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator>=(const Optional<T>& opt, const U& value) {
|
||||
return opt.has_value() ? *opt >= value : false;
|
||||
}
|
||||
|
||||
template <class T, class U>
|
||||
constexpr bool operator>=(const U& value, const Optional<T>& opt) {
|
||||
return opt.has_value() ? value >= *opt : true;
|
||||
}
|
||||
|
||||
template <class T>
|
||||
constexpr Optional<typename std::decay<T>::type> make_optional(T&& value) {
|
||||
return Optional<typename std::decay<T>::type>(std::forward<T>(value));
|
||||
}
|
||||
|
||||
template <class T, class... Args>
|
||||
constexpr Optional<T> make_optional(Args&&... args) {
|
||||
return Optional<T>(in_place, std::forward<Args>(args)...);
|
||||
}
|
||||
|
||||
template <class T, class U, class... Args>
|
||||
constexpr Optional<T> make_optional(std::initializer_list<U> il,
|
||||
Args&&... args) {
|
||||
return Optional<T>(in_place, il, std::forward<Args>(args)...);
|
||||
}
|
||||
|
||||
// Partial specialization for a function template is not allowed. Also, it is
|
||||
// not allowed to add overload function to std namespace, while it is allowed
|
||||
// to specialize the template in std. Thus, swap() (kind of) overloading is
|
||||
// defined in base namespace, instead.
|
||||
template <class T>
|
||||
typename std::enable_if<std::is_move_constructible<T>::value &&
|
||||
internal::IsSwappable<T>::value>::type
|
||||
swap(Optional<T>& lhs, Optional<T>& rhs) {
|
||||
lhs.swap(rhs);
|
||||
}
|
||||
using Optional = absl::optional<T>;
|
||||
using absl::in_place;
|
||||
using absl::in_place_t;
|
||||
using absl::make_optional;
|
||||
using absl::nullopt;
|
||||
using absl::nullopt_t;
|
||||
|
||||
} // namespace base
|
||||
} // namespace v8
|
||||
|
||||
@ -9,6 +9,7 @@ v8_executable("wasm_api_tests") {
|
||||
|
||||
deps = [
|
||||
"../:common_test_headers",
|
||||
"../..:v8_abseil",
|
||||
"../..:v8_internal_headers",
|
||||
"../..:v8_maybe_icu",
|
||||
"../..:wee8",
|
||||
|
||||
@ -26,6 +26,7 @@ group("v8_run_gcmole") {
|
||||
"../../test/cctest/",
|
||||
"../../test/common/",
|
||||
"../../testing/gtest/include/gtest/gtest_prod.h",
|
||||
"../../third_party/abseil-cpp/",
|
||||
"../../third_party/googletest/src/googletest/include/gtest/gtest_prod.h",
|
||||
"../../third_party/icu/source/",
|
||||
"../../third_party/wasm-api/wasm.h",
|
||||
|
||||
@ -103,6 +103,7 @@ def MakeClangCommandLine(plugin, plugin_args, arch_cfg, clang_bin_dir,
|
||||
"-I./",
|
||||
"-Iinclude/",
|
||||
"-Iout/build/gen",
|
||||
"-Ithird_party/abseil-cpp",
|
||||
"-Ithird_party/icu/source/common",
|
||||
"-Ithird_party/icu/source/i18n",
|
||||
] + arch_cfg.arch_options)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user