6abeec6299
Segregates result utilities into: - result.hh - basic definitions related to results with exception containers, - result_combinators.hh - combinators for working with results in conjunction with futures, - result_loop.hh - loop-like combinators, currently has only result_parallel_for_each. The motivation for the split is: 1. In headers, usually only result.hh will be needed, so no need to force most .cc files to compile definitions from other files, 2. Less files need to be recompiled when a combinator is added to result_combinators or result_loop. As a bonus, `result_with_exception` was moved from `utils::internal` to just `utils`.
48 lines
1.4 KiB
C++
48 lines
1.4 KiB
C++
/*
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* Copyright 2022-present ScyllaDB
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*/
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/*
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* SPDX-License-Identifier: AGPL-3.0-or-later
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*/
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#pragma once
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// Basic utilities which allow to start working with boost::outcome::result
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// in conjunction with our exception_container.
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#include <boost/outcome/policy/base.hpp>
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#include <boost/outcome/result.hpp>
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#include "utils/exception_container.hh"
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namespace bo = BOOST_OUTCOME_V2_NAMESPACE;
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namespace utils {
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// A policy which throws the container_error associated with the result
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// if there was an attempt to access value while it was not present.
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struct exception_container_throw_policy : bo::policy::base {
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template<class Impl> static constexpr void wide_value_check(Impl&& self) {
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if (!base::_has_value(self)) {
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base::_error(self).throw_me();
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}
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}
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template<class Impl> static constexpr void wide_error_check(Impl&& self) {
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if (!base::_has_error(self)) {
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throw bo::bad_result_access("no error");
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}
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}
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};
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template<typename T, typename... Exs>
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using result_with_exception = bo::result<T, exception_container<Exs...>, exception_container_throw_policy>;
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template<typename R>
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concept ExceptionContainerResult = bo::is_basic_result<R>::value && ExceptionContainer<typename R::error_type>;
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template<typename F>
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concept ExceptionContainerResultFuture = seastar::is_future<F>::value && ExceptionContainerResult<typename F::value_type>;
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}
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