79 lines
2.0 KiB
C++
79 lines
2.0 KiB
C++
/*
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* Copyright 2015 ScyllaDB
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*/
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/*
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* This file is part of Scylla.
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*
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* Scylla is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Scylla is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <type_traits>
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#include <memory>
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#include <seastar/core/future.hh>
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#pragma once
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//
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// Utility for adapting types which are not nothrow move constructible into such
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// by wrapping them if necessary.
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//
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// Example usage:
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//
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// T val{};
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// using traits = noexcept_movable<T>;
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// auto f = make_ready_future<typename traits::type>(traits::wrap(std::move(val)));
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// T val2 = traits::unwrap(f.get0());
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//
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template<typename T, typename Enable = void>
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struct noexcept_movable;
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template<typename T>
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struct noexcept_movable<T, std::enable_if_t<std::is_nothrow_move_constructible<T>::value>> {
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using type = T;
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static type wrap(T&& v) {
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return std::move(v);
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}
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static future<T> wrap(future<T>&& v) {
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return std::move(v);
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}
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static T unwrap(type&& v) {
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return std::move(v);
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}
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static future<T> unwrap(future<type>&& v) {
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return std::move(v);
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}
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};
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template<typename T>
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struct noexcept_movable<T, std::enable_if_t<!std::is_nothrow_move_constructible<T>::value>> {
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using type = std::unique_ptr<T>;
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static type wrap(T&& v) {
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return std::make_unique<T>(std::move(v));
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}
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static T unwrap(type&& v) {
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return std::move(*v);
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}
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};
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template<typename T>
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using noexcept_movable_t = typename noexcept_movable<T>::type;
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