529 lines
16 KiB
C++
529 lines
16 KiB
C++
/*
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/*
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*
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* Author: Eric Niebler <eniebler@fb.com>
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*/
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#include <folly/Portability.h>
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namespace folly {
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template <class Fn>
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struct exception_wrapper::arg_type_
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: public arg_type_<decltype(&Fn::operator())> {};
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template <class Ret, class Class, class Arg>
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struct exception_wrapper::arg_type_<Ret (Class::*)(Arg)> {
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using type = Arg;
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};
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template <class Ret, class Class, class Arg>
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struct exception_wrapper::arg_type_<Ret (Class::*)(Arg) const> {
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using type = Arg;
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};
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template <class Ret, class Arg>
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struct exception_wrapper::arg_type_<Ret(Arg)> {
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using type = Arg;
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};
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template <class Ret, class Arg>
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struct exception_wrapper::arg_type_<Ret (*)(Arg)> {
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using type = Arg;
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};
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template <class Ret, class Class>
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struct exception_wrapper::arg_type_<Ret (Class::*)(...)> {
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using type = AnyException;
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};
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template <class Ret, class Class>
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struct exception_wrapper::arg_type_<Ret (Class::*)(...) const> {
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using type = AnyException;
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};
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template <class Ret>
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struct exception_wrapper::arg_type_<Ret(...)> {
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using type = AnyException;
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};
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template <class Ret>
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struct exception_wrapper::arg_type_<Ret (*)(...)> {
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using type = AnyException;
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};
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#ifdef FOLLY_HAVE_NOEXCEPT_FUNCTION_TYPE
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template <class Ret, class Class, class Arg>
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struct exception_wrapper::arg_type_<Ret (Class::*)(Arg) noexcept> {
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using type = Arg;
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};
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template <class Ret, class Class, class Arg>
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struct exception_wrapper::arg_type_<Ret (Class::*)(Arg) const noexcept> {
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using type = Arg;
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};
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template <class Ret, class Arg>
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struct exception_wrapper::arg_type_<Ret(Arg) noexcept> {
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using type = Arg;
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};
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template <class Ret, class Arg>
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struct exception_wrapper::arg_type_<Ret (*)(Arg) noexcept> {
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using type = Arg;
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};
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template <class Ret, class Class>
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struct exception_wrapper::arg_type_<Ret (Class::*)(...) noexcept> {
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using type = AnyException;
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};
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template <class Ret, class Class>
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struct exception_wrapper::arg_type_<Ret (Class::*)(...) const noexcept> {
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using type = AnyException;
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};
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template <class Ret>
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struct exception_wrapper::arg_type_<Ret(...) noexcept> {
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using type = AnyException;
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};
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template <class Ret>
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struct exception_wrapper::arg_type_<Ret (*)(...) noexcept> {
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using type = AnyException;
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};
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#endif
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struct exception_wrapper::with_exception_from_fn_ {
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template <typename, typename Fn>
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using apply = arg_type<Fn>;
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};
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struct exception_wrapper::with_exception_from_ex_ {
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template <typename Ex, typename>
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using apply = Ex;
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};
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template <class Ret, class... Args>
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inline Ret exception_wrapper::noop_(Args...) {
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return Ret();
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}
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inline std::type_info const* exception_wrapper::uninit_type_(
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exception_wrapper const*) {
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return &typeid(void);
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}
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template <class Ex, typename... As>
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inline exception_wrapper::Buffer::Buffer(in_place_type_t<Ex>, As&&... as_) {
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::new (static_cast<void*>(&buff_)) Ex(std::forward<As>(as_)...);
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}
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template <class Ex>
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inline Ex& exception_wrapper::Buffer::as() noexcept {
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return *static_cast<Ex*>(static_cast<void*>(&buff_));
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}
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template <class Ex>
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inline Ex const& exception_wrapper::Buffer::as() const noexcept {
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return *static_cast<Ex const*>(static_cast<void const*>(&buff_));
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}
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inline std::exception const* exception_wrapper::as_exception_or_null_(
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std::exception const& ex) {
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return &ex;
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}
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inline std::exception const* exception_wrapper::as_exception_or_null_(
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AnyException) {
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return nullptr;
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}
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inline void exception_wrapper::ExceptionPtr::copy_(
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exception_wrapper const* from, exception_wrapper* to) {
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::new (static_cast<void*>(&to->eptr_)) ExceptionPtr(from->eptr_);
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}
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inline void exception_wrapper::ExceptionPtr::move_(
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exception_wrapper* from, exception_wrapper* to) {
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::new (static_cast<void*>(&to->eptr_)) ExceptionPtr(std::move(from->eptr_));
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delete_(from);
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}
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inline void exception_wrapper::ExceptionPtr::delete_(exception_wrapper* that) {
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that->eptr_.~ExceptionPtr();
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that->vptr_ = &uninit_;
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}
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[[noreturn]] inline void exception_wrapper::ExceptionPtr::throw_(
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exception_wrapper const* that) {
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std::rethrow_exception(that->eptr_.ptr_);
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}
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inline std::type_info const* exception_wrapper::ExceptionPtr::type_(
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exception_wrapper const* that) {
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return exception_ptr_get_type(that->eptr_.ptr_);
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}
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inline std::exception const* exception_wrapper::ExceptionPtr::get_exception_(
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exception_wrapper const* that) {
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return exception_ptr_get_object<std::exception>(that->eptr_.ptr_);
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}
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inline exception_wrapper exception_wrapper::ExceptionPtr::get_exception_ptr_(
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exception_wrapper const* that) {
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return *that;
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}
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template <class Ex>
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inline void exception_wrapper::InPlace<Ex>::copy_(
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exception_wrapper const* from, exception_wrapper* to) {
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::new (static_cast<void*>(std::addressof(to->buff_.as<Ex>())))
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Ex(from->buff_.as<Ex>());
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}
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template <class Ex>
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inline void exception_wrapper::InPlace<Ex>::move_(
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exception_wrapper* from, exception_wrapper* to) {
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::new (static_cast<void*>(std::addressof(to->buff_.as<Ex>())))
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Ex(std::move(from->buff_.as<Ex>()));
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delete_(from);
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}
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template <class Ex>
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inline void exception_wrapper::InPlace<Ex>::delete_(exception_wrapper* that) {
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that->buff_.as<Ex>().~Ex();
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that->vptr_ = &uninit_;
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}
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template <class Ex>
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[[noreturn]] inline void exception_wrapper::InPlace<Ex>::throw_(
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exception_wrapper const* that) {
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throw that->buff_.as<Ex>();
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}
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template <class Ex>
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inline std::type_info const* exception_wrapper::InPlace<Ex>::type_(
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exception_wrapper const*) {
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return &typeid(Ex);
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}
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template <class Ex>
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inline std::exception const* exception_wrapper::InPlace<Ex>::get_exception_(
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exception_wrapper const* that) {
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return as_exception_or_null_(that->buff_.as<Ex>());
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}
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template <class Ex>
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inline exception_wrapper exception_wrapper::InPlace<Ex>::get_exception_ptr_(
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exception_wrapper const* that) {
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try {
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throw_(that);
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} catch (...) {
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return exception_wrapper{std::current_exception()};
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}
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}
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template <class Ex>
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[[noreturn]] inline void exception_wrapper::SharedPtr::Impl<Ex>::throw_()
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const {
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throw ex_;
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}
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template <class Ex>
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inline std::exception const*
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exception_wrapper::SharedPtr::Impl<Ex>::get_exception_() const noexcept {
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return as_exception_or_null_(ex_);
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}
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template <class Ex>
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inline exception_wrapper
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exception_wrapper::SharedPtr::Impl<Ex>::get_exception_ptr_() const noexcept {
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try {
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throw_();
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} catch (...) {
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return exception_wrapper{std::current_exception()};
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}
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}
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inline void exception_wrapper::SharedPtr::copy_(
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exception_wrapper const* from, exception_wrapper* to) {
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::new (static_cast<void*>(std::addressof(to->sptr_))) SharedPtr(from->sptr_);
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}
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inline void exception_wrapper::SharedPtr::move_(
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exception_wrapper* from, exception_wrapper* to) {
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::new (static_cast<void*>(std::addressof(to->sptr_)))
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SharedPtr(std::move(from->sptr_));
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delete_(from);
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}
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inline void exception_wrapper::SharedPtr::delete_(exception_wrapper* that) {
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that->sptr_.~SharedPtr();
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that->vptr_ = &uninit_;
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}
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[[noreturn]] inline void exception_wrapper::SharedPtr::throw_(
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exception_wrapper const* that) {
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that->sptr_.ptr_->throw_();
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folly::assume_unreachable();
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}
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inline std::type_info const* exception_wrapper::SharedPtr::type_(
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exception_wrapper const* that) {
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return that->sptr_.ptr_->info_;
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}
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inline std::exception const* exception_wrapper::SharedPtr::get_exception_(
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exception_wrapper const* that) {
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return that->sptr_.ptr_->get_exception_();
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}
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inline exception_wrapper exception_wrapper::SharedPtr::get_exception_ptr_(
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exception_wrapper const* that) {
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return that->sptr_.ptr_->get_exception_ptr_();
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}
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template <class Ex, typename... As>
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inline exception_wrapper::exception_wrapper(
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ThrownTag, in_place_type_t<Ex>, As&&... as)
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: eptr_{std::make_exception_ptr(Ex(std::forward<As>(as)...))},
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vptr_(&ExceptionPtr::ops_) {}
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template <class Ex, typename... As>
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inline exception_wrapper::exception_wrapper(
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OnHeapTag, in_place_type_t<Ex>, As&&... as)
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: sptr_{std::make_shared<SharedPtr::Impl<Ex>>(std::forward<As>(as)...)},
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vptr_(&SharedPtr::ops_) {}
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template <class Ex, typename... As>
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inline exception_wrapper::exception_wrapper(
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InSituTag, in_place_type_t<Ex>, As&&... as)
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: buff_{in_place_type<Ex>, std::forward<As>(as)...},
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vptr_(&InPlace<Ex>::ops_) {}
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inline exception_wrapper::exception_wrapper(exception_wrapper&& that) noexcept
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: exception_wrapper{} {
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(vptr_ = that.vptr_)->move_(&that, this); // Move into *this, won't throw
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}
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inline exception_wrapper::exception_wrapper(
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exception_wrapper const& that) noexcept
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: exception_wrapper{} {
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that.vptr_->copy_(&that, this); // Copy into *this, won't throw
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vptr_ = that.vptr_;
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}
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// If `this == &that`, this move assignment operator leaves the object in a
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// valid but unspecified state.
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inline exception_wrapper& exception_wrapper::operator=(
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exception_wrapper&& that) noexcept {
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vptr_->delete_(this); // Free the current exception
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(vptr_ = that.vptr_)->move_(&that, this); // Move into *this, won't throw
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return *this;
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}
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inline exception_wrapper& exception_wrapper::operator=(
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exception_wrapper const& that) noexcept {
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exception_wrapper(that).swap(*this);
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return *this;
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}
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inline exception_wrapper::~exception_wrapper() {
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reset();
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}
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template <class Ex>
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inline exception_wrapper::exception_wrapper(
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std::exception_ptr const& ptr, Ex& ex) noexcept
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: exception_wrapper{folly::copy(ptr), ex} {}
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template <class Ex>
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inline exception_wrapper::exception_wrapper(
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std::exception_ptr&& ptr, Ex& ex) noexcept
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: eptr_{std::move(ptr)}, vptr_(&ExceptionPtr::ops_) {
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assert(eptr_.ptr_);
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(void)ex;
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assert(exception_ptr_get_object<Ex>(eptr_.ptr_));
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assert(exception_ptr_get_object<Ex>(eptr_.ptr_) == &ex || kIsWindows);
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}
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namespace exception_wrapper_detail {
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template <class Ex>
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Ex&& dont_slice(Ex&& ex) {
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assert(typeid(ex) == typeid(std::decay_t<Ex>) ||
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!"Dynamic and static exception types don't match. Exception would "
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"be sliced when storing in exception_wrapper.");
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return std::forward<Ex>(ex);
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}
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} // namespace exception_wrapper_detail
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template <
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class Ex,
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class Ex_,
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FOLLY_REQUIRES_DEF(Conjunction<
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exception_wrapper::IsStdException<Ex_>,
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exception_wrapper::IsRegularExceptionType<Ex_>>::value)>
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inline exception_wrapper::exception_wrapper(Ex&& ex)
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: exception_wrapper{
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PlacementOf<Ex_>{},
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in_place_type<Ex_>,
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exception_wrapper_detail::dont_slice(std::forward<Ex>(ex))} {}
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template <
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class Ex,
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class Ex_,
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FOLLY_REQUIRES_DEF(exception_wrapper::IsRegularExceptionType<Ex_>::value)>
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inline exception_wrapper::exception_wrapper(in_place_t, Ex&& ex)
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: exception_wrapper{
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PlacementOf<Ex_>{},
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in_place_type<Ex_>,
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exception_wrapper_detail::dont_slice(std::forward<Ex>(ex))} {}
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template <
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class Ex,
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typename... As,
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FOLLY_REQUIRES_DEF(exception_wrapper::IsRegularExceptionType<Ex>::value)>
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inline exception_wrapper::exception_wrapper(in_place_type_t<Ex>, As&&... as)
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: exception_wrapper{
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PlacementOf<Ex>{}, in_place_type<Ex>, std::forward<As>(as)...} {}
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inline void exception_wrapper::swap(exception_wrapper& that) noexcept {
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exception_wrapper tmp(std::move(that));
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that = std::move(*this);
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*this = std::move(tmp);
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}
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inline exception_wrapper::operator bool() const noexcept {
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return vptr_ != &uninit_;
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}
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inline bool exception_wrapper::operator!() const noexcept {
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return !static_cast<bool>(*this);
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}
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inline void exception_wrapper::reset() {
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vptr_->delete_(this);
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}
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inline bool exception_wrapper::has_exception_ptr() const noexcept {
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return vptr_ == &ExceptionPtr::ops_;
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}
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inline std::exception* exception_wrapper::get_exception() noexcept {
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return const_cast<std::exception*>(vptr_->get_exception_(this));
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}
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inline std::exception const* exception_wrapper::get_exception() const noexcept {
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return vptr_->get_exception_(this);
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}
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template <typename Ex>
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inline Ex* exception_wrapper::get_exception() noexcept {
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constexpr auto stdexcept = std::is_base_of<std::exception, Ex>::value;
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if (vptr_ == &ExceptionPtr::ops_) {
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return exception_ptr_get_object<Ex>(eptr_.ptr_);
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} else if (!stdexcept || vptr_ == &uninit_) {
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return nullptr;
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} else {
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using Target = conditional_t<stdexcept, Ex, std::exception>;
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auto const ptr = dynamic_cast<Target*>(get_exception());
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return reinterpret_cast<Ex*>(ptr);
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}
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}
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template <typename Ex>
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inline Ex const* exception_wrapper::get_exception() const noexcept {
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constexpr auto stdexcept = std::is_base_of<std::exception, Ex>::value;
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if (vptr_ == &ExceptionPtr::ops_) {
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return exception_ptr_get_object<Ex>(eptr_.ptr_);
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} else if (!stdexcept || vptr_ == &uninit_) {
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return nullptr;
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} else {
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using Target = conditional_t<stdexcept, Ex, std::exception>;
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auto const ptr = dynamic_cast<Target const*>(get_exception());
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return reinterpret_cast<Ex const*>(ptr);
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}
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}
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inline std::exception_ptr exception_wrapper::to_exception_ptr() noexcept {
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if (*this) {
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// Computing an exception_ptr is expensive so cache the result.
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return (*this = vptr_->get_exception_ptr_(this)).eptr_.ptr_;
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}
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return {};
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}
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inline std::exception_ptr exception_wrapper::to_exception_ptr() const noexcept {
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return vptr_->get_exception_ptr_(this).eptr_.ptr_;
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}
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inline std::type_info const& exception_wrapper::none() noexcept {
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return typeid(void);
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}
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inline std::type_info const& exception_wrapper::type() const noexcept {
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return *vptr_->type_(this);
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}
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inline folly::fbstring exception_wrapper::what() const {
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if (auto e = get_exception()) {
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return class_name() + ": " + e->what();
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}
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return class_name();
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}
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inline folly::fbstring exception_wrapper::class_name() const {
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auto& ti = type();
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return ti == none() ? "" : folly::demangle(ti);
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}
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template <class Ex>
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inline bool exception_wrapper::is_compatible_with() const noexcept {
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return get_exception<Ex>();
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}
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[[noreturn]] inline void exception_wrapper::throw_exception() const {
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vptr_->throw_(this);
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onNoExceptionError(__func__);
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}
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template <class Ex>
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[[noreturn]] inline void exception_wrapper::throw_with_nested(Ex&& ex) const {
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try {
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throw_exception();
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} catch (...) {
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std::throw_with_nested(std::forward<Ex>(ex));
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}
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}
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template <class This, class Fn>
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inline bool exception_wrapper::with_exception_(
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This&, Fn fn_, tag_t<AnyException>) {
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return void(fn_()), true;
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}
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template <class This, class Fn, typename Ex>
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inline bool exception_wrapper::with_exception_(This& this_, Fn fn_, tag_t<Ex>) {
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auto ptr = this_.template get_exception<remove_cvref_t<Ex>>();
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return ptr && (void(fn_(static_cast<Ex&>(*ptr))), true);
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}
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template <class Ex, class This, class Fn>
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inline bool exception_wrapper::with_exception_(This& this_, Fn fn_) {
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using from_fn = with_exception_from_fn_;
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using from_ex = with_exception_from_ex_;
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using from = conditional_t<std::is_void<Ex>::value, from_fn, from_ex>;
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using type = typename from::template apply<Ex, Fn>;
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return with_exception_(this_, fn_, tag<type>);
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}
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template <class This, class... CatchFns>
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inline void exception_wrapper::handle_(
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This& this_, char const* name, CatchFns&... fns) {
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using _ = bool[];
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if (!this_) {
|
|
onNoExceptionError(name);
|
|
}
|
|
bool handled = false;
|
|
void(_{false, (handled = handled || with_exception_<void>(this_, fns))...});
|
|
if (!handled) {
|
|
this_.throw_exception();
|
|
}
|
|
}
|
|
|
|
template <class Ex, class Fn>
|
|
inline bool exception_wrapper::with_exception(Fn fn) {
|
|
return with_exception_<Ex>(*this, std::move(fn));
|
|
}
|
|
template <class Ex, class Fn>
|
|
inline bool exception_wrapper::with_exception(Fn fn) const {
|
|
return with_exception_<Ex const>(*this, std::move(fn));
|
|
}
|
|
|
|
template <class... CatchFns>
|
|
inline void exception_wrapper::handle(CatchFns... fns) {
|
|
handle_(*this, __func__, fns...);
|
|
}
|
|
template <class... CatchFns>
|
|
inline void exception_wrapper::handle(CatchFns... fns) const {
|
|
handle_(*this, __func__, fns...);
|
|
}
|
|
|
|
} // namespace folly
|