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- #ifndef BOOST_LEAF_CAPTURE_HPP_INCLUDED
- #define BOOST_LEAF_CAPTURE_HPP_INCLUDED
- /// Copyright (c) 2018-2021 Emil Dotchevski and Reverge Studios, Inc.
- /// Distributed under the Boost Software License, Version 1.0. (See accompanying
- /// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
- #ifndef BOOST_LEAF_ENABLE_WARNINGS ///
- # if defined(_MSC_VER) ///
- # pragma warning(push,1) ///
- # elif defined(__clang__) ///
- # pragma clang system_header ///
- # elif (__GNUC__*100+__GNUC_MINOR__>301) ///
- # pragma GCC system_header ///
- # endif ///
- #endif ///
- #include <boost/leaf/exception.hpp>
- #include <boost/leaf/on_error.hpp>
- namespace boost { namespace leaf {
- namespace leaf_detail
- {
- template <class R, bool IsResult = is_result_type<R>::value>
- struct is_result_tag;
- template <class R>
- struct is_result_tag<R, false>
- {
- };
- template <class R>
- struct is_result_tag<R, true>
- {
- };
- }
- #ifdef BOOST_LEAF_NO_EXCEPTIONS
- namespace leaf_detail
- {
- template <class R, class F, class... A>
- inline
- decltype(std::declval<F>()(std::forward<A>(std::declval<A>())...))
- capture_impl(is_result_tag<R, false>, context_ptr && ctx, F && f, A... a) noexcept
- {
- auto active_context = activate_context(*ctx);
- return std::forward<F>(f)(std::forward<A>(a)...);
- }
- template <class R, class F, class... A>
- inline
- decltype(std::declval<F>()(std::forward<A>(std::declval<A>())...))
- capture_impl(is_result_tag<R, true>, context_ptr && ctx, F && f, A... a) noexcept
- {
- auto active_context = activate_context(*ctx);
- if( auto r = std::forward<F>(f)(std::forward<A>(a)...) )
- return r;
- else
- {
- ctx->captured_id_ = r.error();
- return std::move(ctx);
- }
- }
- template <class R, class Future>
- inline
- decltype(std::declval<Future>().get())
- future_get_impl(is_result_tag<R, false>, Future & fut) noexcept
- {
- return fut.get();
- }
- template <class R, class Future>
- inline
- decltype(std::declval<Future>().get())
- future_get_impl(is_result_tag<R, true>, Future & fut) noexcept
- {
- if( auto r = fut.get() )
- return r;
- else
- return error_id(r.error()); // unloads
- }
- }
- #else
- namespace leaf_detail
- {
- class capturing_exception:
- public std::exception
- {
- std::exception_ptr ex_;
- context_ptr ctx_;
- public:
- capturing_exception(std::exception_ptr && ex, context_ptr && ctx) noexcept:
- ex_(std::move(ex)),
- ctx_(std::move(ctx))
- {
- BOOST_LEAF_ASSERT(ex_);
- BOOST_LEAF_ASSERT(ctx_);
- BOOST_LEAF_ASSERT(ctx_->captured_id_);
- }
- [[noreturn]] void unload_and_rethrow_original_exception() const
- {
- BOOST_LEAF_ASSERT(ctx_->captured_id_);
- auto active_context = activate_context(*ctx_);
- id_factory<>::current_id = ctx_->captured_id_.value();
- std::rethrow_exception(ex_);
- }
- template <class CharT, class Traits>
- void print( std::basic_ostream<CharT, Traits> & os ) const
- {
- ctx_->print(os);
- }
- };
- template <class R, class F, class... A>
- inline
- decltype(std::declval<F>()(std::forward<A>(std::declval<A>())...))
- capture_impl(is_result_tag<R, false>, context_ptr && ctx, F && f, A... a)
- {
- auto active_context = activate_context(*ctx);
- error_monitor cur_err;
- try
- {
- return std::forward<F>(f)(std::forward<A>(a)...);
- }
- catch( capturing_exception const & )
- {
- throw;
- }
- catch( exception_base const & e )
- {
- ctx->captured_id_ = e.get_error_id();
- throw_exception( capturing_exception(std::current_exception(), std::move(ctx)) );
- }
- catch(...)
- {
- ctx->captured_id_ = cur_err.assigned_error_id();
- throw_exception( capturing_exception(std::current_exception(), std::move(ctx)) );
- }
- }
- template <class R, class F, class... A>
- inline
- decltype(std::declval<F>()(std::forward<A>(std::declval<A>())...))
- capture_impl(is_result_tag<R, true>, context_ptr && ctx, F && f, A... a)
- {
- auto active_context = activate_context(*ctx);
- error_monitor cur_err;
- try
- {
- if( auto && r = std::forward<F>(f)(std::forward<A>(a)...) )
- return std::move(r);
- else
- {
- ctx->captured_id_ = r.error();
- return std::move(ctx);
- }
- }
- catch( capturing_exception const & )
- {
- throw;
- }
- catch( exception_base const & e )
- {
- ctx->captured_id_ = e.get_error_id();
- throw_exception( capturing_exception(std::current_exception(), std::move(ctx)) );
- }
- catch(...)
- {
- ctx->captured_id_ = cur_err.assigned_error_id();
- throw_exception( capturing_exception(std::current_exception(), std::move(ctx)) );
- }
- }
- template <class R, class Future>
- inline
- decltype(std::declval<Future>().get())
- future_get_impl(is_result_tag<R, false>, Future & fut )
- {
- try
- {
- return fut.get();
- }
- catch( capturing_exception const & cap )
- {
- cap.unload_and_rethrow_original_exception();
- }
- }
- template <class R, class Future>
- inline
- decltype(std::declval<Future>().get())
- future_get_impl(is_result_tag<R, true>, Future & fut )
- {
- try
- {
- if( auto r = fut.get() )
- return r;
- else
- return error_id(r.error()); // unloads
- }
- catch( capturing_exception const & cap )
- {
- cap.unload_and_rethrow_original_exception();
- }
- }
- }
- #endif
- template <class F, class... A>
- inline
- decltype(std::declval<F>()(std::forward<A>(std::declval<A>())...))
- capture(context_ptr && ctx, F && f, A... a)
- {
- using namespace leaf_detail;
- return capture_impl(is_result_tag<decltype(std::declval<F>()(std::forward<A>(std::declval<A>())...))>(), std::move(ctx), std::forward<F>(f), std::forward<A>(a)...);
- }
- template <class Future>
- inline
- decltype(std::declval<Future>().get())
- future_get( Future & fut )
- {
- using namespace leaf_detail;
- return future_get_impl(is_result_tag<decltype(std::declval<Future>().get())>(), fut);
- }
- ////////////////////////////////////////
- #ifndef BOOST_LEAF_NO_EXCEPTIONS
- template <class T>
- class result;
- namespace leaf_detail
- {
- inline error_id catch_exceptions_helper( std::exception const & ex, leaf_detail_mp11::mp_list<> )
- {
- return leaf::new_error(std::current_exception());
- }
- template <class Ex1, class... Ex>
- inline error_id catch_exceptions_helper( std::exception const & ex, leaf_detail_mp11::mp_list<Ex1,Ex...> )
- {
- if( Ex1 const * p = dynamic_cast<Ex1 const *>(&ex) )
- return catch_exceptions_helper(ex, leaf_detail_mp11::mp_list<Ex...>{ }).load(*p);
- else
- return catch_exceptions_helper(ex, leaf_detail_mp11::mp_list<Ex...>{ });
- }
- template <class T>
- struct deduce_exception_to_result_return_type_impl
- {
- using type = result<T>;
- };
- template <class T>
- struct deduce_exception_to_result_return_type_impl<result<T>>
- {
- using type = result<T>;
- };
- template <class T>
- using deduce_exception_to_result_return_type = typename deduce_exception_to_result_return_type_impl<T>::type;
- }
- template <class... Ex, class F>
- inline
- leaf_detail::deduce_exception_to_result_return_type<leaf_detail::fn_return_type<F>>
- exception_to_result( F && f ) noexcept
- {
- try
- {
- return std::forward<F>(f)();
- }
- catch( std::exception const & ex )
- {
- return leaf_detail::catch_exceptions_helper(ex, leaf_detail_mp11::mp_list<Ex...>());
- }
- catch(...)
- {
- return leaf::new_error(std::current_exception());
- }
- }
- #endif
- } }
- #if defined(_MSC_VER) && !defined(BOOST_LEAF_ENABLE_WARNINGS) ///
- #pragma warning(pop) ///
- #endif ///
- #endif
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