#ifndef BOOST_LEAF_HANDLE_ERRORS_HPP_INCLUDED
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#define BOOST_LEAF_HANDLE_ERRORS_HPP_INCLUDED
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// Copyright (c) 2018-2020 Emil Dotchevski and Reverge Studios, Inc.
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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#ifndef BOOST_LEAF_ENABLE_WARNINGS
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# if defined(__clang__)
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# pragma clang system_header
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# elif (__GNUC__*100+__GNUC_MINOR__>301)
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# pragma GCC system_header
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# elif defined(_MSC_VER)
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# pragma warning(push,1)
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# endif
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#endif
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#include <boost/leaf/context.hpp>
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#include <boost/leaf/detail/demangle.hpp>
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#ifndef BOOST_LEAF_NO_EXCEPTIONS
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# include <boost/leaf/capture.hpp>
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#endif
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namespace boost { namespace leaf {
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class error_info
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{
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error_info & operator=( error_info const & ) = delete;
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#ifndef BOOST_LEAF_NO_EXCEPTIONS
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static error_id unpack_error_id( std::exception const * ex ) noexcept
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{
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if( std::system_error const * se = dynamic_cast<std::system_error const *>(ex) )
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if( is_error_id(se->code()) )
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return leaf_detail::make_error_id(se->code().value());
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if( std::error_code const * ec = dynamic_cast<std::error_code const *>(ex) )
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if( is_error_id(*ec) )
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return leaf_detail::make_error_id(ec->value());
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if( error_id const * err_id = dynamic_cast<error_id const *>(ex) )
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return *err_id;
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return current_error();
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}
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std::exception * const ex_;
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#endif
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error_id const err_id_;
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protected:
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error_info( error_info const & ) noexcept = default;
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template <class CharT, class Traits>
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void print( std::basic_ostream<CharT, Traits> & os ) const
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{
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os << "Error ID = " << err_id_.value();
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#ifndef BOOST_LEAF_NO_EXCEPTIONS
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if( ex_ )
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{
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os <<
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"\nException dynamic type: " << leaf_detail::demangle(typeid(*ex_).name()) <<
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"\nstd::exception::what(): " << ex_->what();
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}
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#endif
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}
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public:
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BOOST_LEAF_CONSTEXPR explicit error_info( error_id id ) noexcept:
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#ifndef BOOST_LEAF_NO_EXCEPTIONS
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ex_(0),
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#endif
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err_id_(id)
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{
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}
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#ifndef BOOST_LEAF_NO_EXCEPTIONS
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explicit error_info( std::exception * ex ) noexcept:
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ex_(ex),
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err_id_(unpack_error_id(ex_))
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{
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}
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#endif
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BOOST_LEAF_CONSTEXPR error_id error() const noexcept
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{
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return err_id_;
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}
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BOOST_LEAF_CONSTEXPR std::exception * exception() const noexcept
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{
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#ifdef BOOST_LEAF_NO_EXCEPTIONS
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return nullptr;
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#else
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return ex_;
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#endif
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}
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template <class CharT, class Traits>
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friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, error_info const & x )
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{
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os << "leaf::error_info: ";
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x.print(os);
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return os << '\n';
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}
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};
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////////////////////////////////////////
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#if BOOST_LEAF_DIAGNOSTICS
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class diagnostic_info: public error_info
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{
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leaf_detail::e_unexpected_count const * e_uc_;
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void const * tup_;
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void (*print_)( std::ostream &, void const * tup, int key_to_print );
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protected:
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diagnostic_info( diagnostic_info const & ) noexcept = default;
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template <class Tup>
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BOOST_LEAF_CONSTEXPR diagnostic_info( error_info const & ei, leaf_detail::e_unexpected_count const * e_uc, Tup const & tup ) noexcept:
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error_info(ei),
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e_uc_(e_uc),
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tup_(&tup),
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print_(&leaf_detail::tuple_for_each<std::tuple_size<Tup>::value, Tup>::print)
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{
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}
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public:
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template <class CharT, class Traits>
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friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, diagnostic_info const & x )
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{
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os << "leaf::diagnostic_info for ";
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x.print(os);
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os << ":\n";
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x.print_(os, x.tup_, x.error().value());
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if( x.e_uc_ )
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x.e_uc_->print(os);
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return os;
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}
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};
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namespace leaf_detail
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{
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struct diagnostic_info_: diagnostic_info
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{
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template <class Tup>
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BOOST_LEAF_CONSTEXPR diagnostic_info_( error_info const & ei, leaf_detail::e_unexpected_count const * e_uc, Tup const & tup ) noexcept:
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diagnostic_info(ei, e_uc, tup)
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{
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}
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};
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template <>
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struct handler_argument_traits<diagnostic_info const &>: handler_argument_always_available<e_unexpected_count>
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{
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template <class Tup>
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BOOST_LEAF_CONSTEXPR static diagnostic_info_ get( Tup const & tup, error_info const & ei ) noexcept
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{
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return diagnostic_info_(ei, handler_argument_traits_defaults<e_unexpected_count>::check(tup, ei), tup);
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}
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};
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}
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#else
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class diagnostic_info: public error_info
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{
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protected:
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diagnostic_info( diagnostic_info const & ) noexcept = default;
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BOOST_LEAF_CONSTEXPR diagnostic_info( error_info const & ei ) noexcept:
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error_info(ei)
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{
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}
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public:
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template <class CharT, class Traits>
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friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, diagnostic_info const & x )
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{
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os <<
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"leaf::diagnostic_info requires #define BOOST_LEAF_DIAGNOSTICS 1\n"
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"leaf::error_info: ";
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x.print(os);
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return os << '\n';
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}
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};
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namespace leaf_detail
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{
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struct diagnostic_info_: diagnostic_info
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{
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BOOST_LEAF_CONSTEXPR diagnostic_info_( error_info const & ei ) noexcept:
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diagnostic_info(ei)
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{
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}
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};
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template <>
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struct handler_argument_traits<diagnostic_info const &>: handler_argument_always_available<void>
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{
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template <class Tup>
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BOOST_LEAF_CONSTEXPR static diagnostic_info_ get( Tup const & tup, error_info const & ei ) noexcept
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{
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return diagnostic_info_(ei);
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}
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};
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}
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#endif
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////////////////////////////////////////
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#if BOOST_LEAF_DIAGNOSTICS
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class verbose_diagnostic_info: public error_info
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{
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leaf_detail::e_unexpected_info const * e_ui_;
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void const * tup_;
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void (*print_)( std::ostream &, void const * tup, int key_to_print );
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protected:
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verbose_diagnostic_info( verbose_diagnostic_info const & ) noexcept = default;
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template <class Tup>
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BOOST_LEAF_CONSTEXPR verbose_diagnostic_info( error_info const & ei, leaf_detail::e_unexpected_info const * e_ui, Tup const & tup ) noexcept:
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error_info(ei),
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e_ui_(e_ui),
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tup_(&tup),
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print_(&leaf_detail::tuple_for_each<std::tuple_size<Tup>::value, Tup>::print)
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{
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}
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public:
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template <class CharT, class Traits>
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friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, verbose_diagnostic_info const & x )
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{
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os << "leaf::verbose_diagnostic_info for ";
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x.print(os);
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os << ":\n";
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x.print_(os, x.tup_, x.error().value());
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if( x.e_ui_ )
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x.e_ui_->print(os);
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return os;
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}
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};
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namespace leaf_detail
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{
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struct verbose_diagnostic_info_: verbose_diagnostic_info
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{
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template <class Tup>
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BOOST_LEAF_CONSTEXPR verbose_diagnostic_info_( error_info const & ei, leaf_detail::e_unexpected_info const * e_ui, Tup const & tup ) noexcept:
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verbose_diagnostic_info(ei, e_ui, tup)
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{
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}
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};
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template <>
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struct handler_argument_traits<verbose_diagnostic_info const &>: handler_argument_always_available<e_unexpected_info>
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{
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template <class Tup>
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BOOST_LEAF_CONSTEXPR static verbose_diagnostic_info_ get( Tup const & tup, error_info const & ei ) noexcept
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{
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return verbose_diagnostic_info_(ei, handler_argument_traits_defaults<e_unexpected_info>::check(tup, ei), tup);
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}
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};
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}
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#else
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class verbose_diagnostic_info: public error_info
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{
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protected:
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verbose_diagnostic_info( verbose_diagnostic_info const & ) noexcept = default;
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BOOST_LEAF_CONSTEXPR verbose_diagnostic_info( error_info const & ei ) noexcept:
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error_info(ei)
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{
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}
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public:
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template <class CharT, class Traits>
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friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, verbose_diagnostic_info const & x )
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{
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os <<
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"leaf::verbose_diagnostic_info requires #define BOOST_LEAF_DIAGNOSTICS 1\n"
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"leaf::error_info: ";
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x.print(os);
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return os << '\n';
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}
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};
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namespace leaf_detail
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{
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struct verbose_diagnostic_info_: verbose_diagnostic_info
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{
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BOOST_LEAF_CONSTEXPR verbose_diagnostic_info_( error_info const & ei ) noexcept:
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verbose_diagnostic_info(ei)
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{
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}
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};
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template <>
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struct handler_argument_traits<verbose_diagnostic_info const &>: handler_argument_always_available<void>
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{
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template <class Tup>
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BOOST_LEAF_CONSTEXPR static verbose_diagnostic_info_ get( Tup const & tup, error_info const & ei ) noexcept
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{
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return verbose_diagnostic_info_(ei);
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}
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};
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}
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#endif
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////////////////////////////////////////
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namespace leaf_detail
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{
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template <class T, class... List>
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struct type_index;
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template <class T, class... Cdr>
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struct type_index<T, T, Cdr...>
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{
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constexpr static int value = 0;
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};
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template <class T, class Car, class... Cdr>
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struct type_index<T, Car, Cdr...>
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{
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constexpr static int value = 1 + type_index<T,Cdr...>::value;
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};
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template <class T, class Tuple>
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struct tuple_type_index;
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template <class T, class... TupleTypes>
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struct tuple_type_index<T,std::tuple<TupleTypes...>>
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{
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constexpr static int value = type_index<T,TupleTypes...>::value;
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};
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#ifndef BOOST_LEAF_NO_EXCEPTIONS
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template <class E, bool = std::is_class<E>::value>
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struct peek_exception;
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template <>
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struct peek_exception<std::exception const, true>
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{
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BOOST_LEAF_CONSTEXPR static std::exception const * peek( error_info const & ei ) noexcept
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{
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return ei.exception();
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}
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};
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template <>
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struct peek_exception<std::exception, true>
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{
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BOOST_LEAF_CONSTEXPR static std::exception * peek( error_info const & ei ) noexcept
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{
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return ei.exception();
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}
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};
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template <>
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struct peek_exception<std::error_code const, true>
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{
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static std::error_code const * peek( error_info const & ei ) noexcept
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{
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auto const ex = ei.exception();
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if( std::system_error * se = dynamic_cast<std::system_error *>(ex) )
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return &se->code();
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else if( std::error_code * ec = dynamic_cast<std::error_code *>(ex) )
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return ec;
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else
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return 0;
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}
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};
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template <>
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struct peek_exception<std::error_code, true>
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{
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static std::error_code * peek( error_info const & ei ) noexcept
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{
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auto const ex = ei.exception();
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if( std::system_error * se = dynamic_cast<std::system_error *>(ex) )
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return const_cast<std::error_code *>(&se->code());
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else if( std::error_code * ec = dynamic_cast<std::error_code *>(ex) )
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return ec;
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else
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return 0;
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}
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};
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template <class E>
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struct peek_exception<E, true>
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{
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static E * peek( error_info const & ei ) noexcept
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{
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return dynamic_cast<E *>(ei.exception());
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}
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};
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template <class E>
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struct peek_exception<E, false>
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{
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BOOST_LEAF_CONSTEXPR static E * peek( error_info const & ) noexcept
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{
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return 0;
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}
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};
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#endif
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template <class E, class SlotsTuple>
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BOOST_LEAF_CONSTEXPR inline
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E const *
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peek( SlotsTuple const & tup, error_info const & ei ) noexcept
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{
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if( error_id err = ei.error() )
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if( E const * e = std::get<tuple_type_index<slot<E>,SlotsTuple>::value>(tup).has_value(err.value()) )
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return e;
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#ifndef BOOST_LEAF_NO_EXCEPTIONS
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else
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return peek_exception<E const>::peek(ei);
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#endif
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return 0;
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}
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template <class E, class SlotsTuple>
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BOOST_LEAF_CONSTEXPR inline
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E *
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peek( SlotsTuple & tup, error_info const & ei ) noexcept
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{
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if( error_id err = ei.error() )
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if( E * e = std::get<tuple_type_index<slot<E>,SlotsTuple>::value>(tup).has_value(err.value()) )
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return e;
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#ifndef BOOST_LEAF_NO_EXCEPTIONS
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else
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return peek_exception<E>::peek(ei);
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#endif
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return 0;
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}
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}
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////////////////////////////////////////
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namespace leaf_detail
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{
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template <class A>
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template <class Tup>
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BOOST_LEAF_CONSTEXPR inline
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typename handler_argument_traits_defaults<A, false>::error_type const *
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handler_argument_traits_defaults<A, false>::
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check( Tup const & tup, error_info const & ei ) noexcept
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{
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return peek<typename std::decay<A>::type>(tup, ei);
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}
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template <class A>
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template <class Tup>
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BOOST_LEAF_CONSTEXPR inline
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typename handler_argument_traits_defaults<A, false>::error_type *
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handler_argument_traits_defaults<A, false>::
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check( Tup & tup, error_info const & ei ) noexcept
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{
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return peek<typename std::decay<A>::type>(tup, ei);
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}
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template <class Tup>
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BOOST_LEAF_CONSTEXPR inline
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std::exception const *
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handler_argument_traits<void>::
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check( Tup const &, error_info const & ei ) noexcept
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{
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return ei.exception();
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}
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template <class Tup, class... List>
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struct check_arguments;
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template <class Tup>
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struct check_arguments<Tup>
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{
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BOOST_LEAF_CONSTEXPR static bool check( Tup const &, error_info const & )
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{
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return true;
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}
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};
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template <class Tup, class Car, class... Cdr>
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struct check_arguments<Tup, Car, Cdr...>
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{
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BOOST_LEAF_CONSTEXPR static bool check( Tup & tup, error_info const & ei ) noexcept
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{
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return handler_argument_traits<Car>::check(tup, ei) && check_arguments<Tup, Cdr...>::check(tup, ei);
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}
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};
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}
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////////////////////////////////////////
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namespace leaf_detail
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{
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template <class>
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struct handler_matches_any_error: std::false_type
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{
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};
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template <template<class...> class L>
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struct handler_matches_any_error<L<>>: std::true_type
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{
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};
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template <template<class...> class L, class Car, class... Cdr>
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struct handler_matches_any_error<L<Car, Cdr...>>
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{
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constexpr static bool value = handler_argument_traits<Car>::always_available && handler_matches_any_error<L<Cdr...>>::value;
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};
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}
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////////////////////////////////////////
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namespace leaf_detail
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{
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template <class Tup, class... A>
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BOOST_LEAF_CONSTEXPR inline bool check_handler_( Tup & tup, error_info const & ei, leaf_detail_mp11::mp_list<A...> ) noexcept
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{
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return check_arguments<Tup, A...>::check(tup, ei);
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}
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template <class R, class F, bool IsResult = is_result_type<R>::value, class FReturnType = fn_return_type<F>>
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struct handler_caller
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{
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template <class Tup, class... A>
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BOOST_LEAF_CONSTEXPR static R call( Tup & tup, error_info const & ei, F && f, leaf_detail_mp11::mp_list<A...> )
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{
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return std::forward<F>(f)( handler_argument_traits<A>::get(tup, ei)... );
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}
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};
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template <template <class...> class Result, class... E, class F>
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struct handler_caller<Result<void, E...>, F, true, void>
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{
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using R = Result<void, E...>;
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template <class Tup, class... A>
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BOOST_LEAF_CONSTEXPR static R call( Tup & tup, error_info const & ei, F && f, leaf_detail_mp11::mp_list<A...> )
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{
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std::forward<F>(f)( handler_argument_traits<A>::get(tup, ei)... );
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return { };
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}
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};
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|
template <class T>
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struct is_tuple: std::false_type { };
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|
template <class... T>
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struct is_tuple<std::tuple<T...>>: std::true_type { };
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template <class... T>
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struct is_tuple<std::tuple<T...> &>: std::true_type { };
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template <class R, class Tup, class H>
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BOOST_LEAF_CONSTEXPR
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inline
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typename std::enable_if<!is_tuple<H>::value, R>::type
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handle_error_( Tup & tup, error_info const & ei, H && h )
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{
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static_assert( handler_matches_any_error<fn_mp_args<H>>::value, "The last handler passed to handle_all must match any error." );
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return handler_caller<R, H>::call( tup, ei, std::forward<H>(h), fn_mp_args<H>{ } );
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}
|
|
template <class R, class Tup, class Car, class... Cdr>
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BOOST_LEAF_CONSTEXPR inline
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typename std::enable_if<!is_tuple<Car>::value, R>::type
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handle_error_( Tup & tup, error_info const & ei, Car && car, Cdr && ... cdr )
|
{
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if( handler_matches_any_error<fn_mp_args<Car>>::value || check_handler_( tup, ei, fn_mp_args<Car>{ } ) )
|
return handler_caller<R, Car>::call( tup, ei, std::forward<Car>(car), fn_mp_args<Car>{ } );
|
else
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return handle_error_<R>( tup, ei, std::forward<Cdr>(cdr)...);
|
}
|
|
template <class R, class Tup, class HTup, size_t ... I>
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BOOST_LEAF_CONSTEXPR inline
|
R
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handle_error_tuple_( Tup & tup, error_info const & ei, leaf_detail_mp11::index_sequence<I...>, HTup && htup )
|
{
|
return handle_error_<R>(tup, ei, std::get<I>(std::forward<HTup>(htup))...);
|
}
|
|
template <class R, class Tup, class HTup, class... Cdr, size_t ... I>
|
BOOST_LEAF_CONSTEXPR inline
|
R
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handle_error_tuple_( Tup & tup, error_info const & ei, leaf_detail_mp11::index_sequence<I...>, HTup && htup, Cdr && ... cdr )
|
{
|
return handle_error_<R>(tup, ei, std::get<I>(std::forward<HTup>(htup))..., std::forward<Cdr>(cdr)...);
|
}
|
|
template <class R, class Tup, class H>
|
BOOST_LEAF_CONSTEXPR inline
|
typename std::enable_if<is_tuple<H>::value, R>::type
|
handle_error_( Tup & tup, error_info const & ei, H && h )
|
{
|
return handle_error_tuple_<R>(
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tup,
|
ei,
|
leaf_detail_mp11::make_index_sequence<std::tuple_size<typename std::decay<H>::type>::value>(),
|
std::forward<H>(h));
|
}
|
|
template <class R, class Tup, class Car, class... Cdr>
|
BOOST_LEAF_CONSTEXPR inline
|
typename std::enable_if<is_tuple<Car>::value, R>::type
|
handle_error_( Tup & tup, error_info const & ei, Car && car, Cdr && ... cdr )
|
{
|
return handle_error_tuple_<R>(
|
tup,
|
ei,
|
leaf_detail_mp11::make_index_sequence<std::tuple_size<typename std::decay<Car>::type>::value>(),
|
std::forward<Car>(car),
|
std::forward<Cdr>(cdr)...);
|
}
|
}
|
|
////////////////////////////////////////
|
|
template <class... E>
|
template <class R, class... H>
|
BOOST_LEAF_CONSTEXPR BOOST_LEAF_ALWAYS_INLINE
|
R
|
context<E...>::
|
handle_error( error_id id, H && ... h ) const
|
{
|
BOOST_LEAF_ASSERT(!is_active());
|
return leaf_detail::handle_error_<R>(tup(), error_info(id), std::forward<H>(h)...);
|
}
|
|
template <class... E>
|
template <class R, class... H>
|
BOOST_LEAF_CONSTEXPR BOOST_LEAF_ALWAYS_INLINE
|
R
|
context<E...>::
|
handle_error( error_id id, H && ... h )
|
{
|
BOOST_LEAF_ASSERT(!is_active());
|
return leaf_detail::handle_error_<R>(tup(), error_info(id), std::forward<H>(h)...);
|
}
|
|
////////////////////////////////////////
|
|
#ifdef BOOST_LEAF_NO_EXCEPTIONS
|
|
template <class TryBlock, class... H>
|
BOOST_LEAF_CONSTEXPR inline
|
typename std::decay<decltype(std::declval<TryBlock>()().value())>::type
|
try_handle_all( TryBlock && try_block, H && ... h ) noexcept
|
{
|
static_assert(is_result_type<decltype(std::declval<TryBlock>()())>::value, "The return type of the try_block passed to a try_handle_all function must be registered with leaf::is_result_type");
|
context_type_from_handlers<H...> ctx;
|
auto active_context = activate_context(ctx);
|
if( auto r = std::forward<TryBlock>(try_block)() )
|
return r.value();
|
else
|
{
|
error_id id = r.error();
|
ctx.deactivate();
|
using R = typename std::decay<decltype(std::declval<TryBlock>()().value())>::type;
|
return ctx.template handle_error<R>(std::move(id), std::forward<H>(h)...);
|
}
|
}
|
|
template <class TryBlock, class... H>
|
BOOST_LEAF_NODISCARD BOOST_LEAF_CONSTEXPR inline
|
typename std::decay<decltype(std::declval<TryBlock>()())>::type
|
try_handle_some( TryBlock && try_block, H && ... h ) noexcept
|
{
|
static_assert(is_result_type<decltype(std::declval<TryBlock>()())>::value, "The return type of the try_block passed to a try_handle_some function must be registered with leaf::is_result_type");
|
context_type_from_handlers<H...> ctx;
|
auto active_context = activate_context(ctx);
|
if( auto r = std::forward<TryBlock>(try_block)() )
|
return r;
|
else
|
{
|
error_id id = r.error();
|
ctx.deactivate();
|
using R = typename std::decay<decltype(std::declval<TryBlock>()())>::type;
|
auto rr = ctx.template handle_error<R>(std::move(id), std::forward<H>(h)..., [&r]()->R { return std::move(r); });
|
if( !rr )
|
ctx.propagate();
|
return rr;
|
}
|
}
|
|
template <class TryBlock, class... H>
|
BOOST_LEAF_CONSTEXPR inline
|
decltype(std::declval<TryBlock>()())
|
try_catch( TryBlock && try_block, H && ... ) noexcept
|
{
|
static_assert(sizeof(context_type_from_handlers<H...>) > 0,
|
"When exceptions are disabled, try_catch can't fail and has no use for the handlers, but this ensures that the supplied H... types are compatible.");
|
return std::forward<TryBlock>(try_block)();
|
}
|
|
#else
|
|
namespace leaf_detail
|
{
|
template <class Ctx, class TryBlock, class... H>
|
decltype(std::declval<TryBlock>()())
|
try_catch_( Ctx & ctx, TryBlock && try_block, H && ... h )
|
{
|
using namespace leaf_detail;
|
BOOST_LEAF_ASSERT(ctx.is_active());
|
using R = decltype(std::declval<TryBlock>()());
|
try
|
{
|
return std::forward<TryBlock>(try_block)();
|
}
|
catch( capturing_exception const & cap )
|
{
|
try
|
{
|
cap.unload_and_rethrow_original_exception();
|
}
|
catch( std::exception & ex )
|
{
|
ctx.deactivate();
|
return handle_error_<R>(ctx.tup(), error_info(&ex), std::forward<H>(h)...,
|
[]() -> R { throw; } );
|
}
|
catch(...)
|
{
|
ctx.deactivate();
|
return handle_error_<R>(ctx.tup(), error_info(nullptr), std::forward<H>(h)...,
|
[]() -> R { throw; } );
|
}
|
}
|
catch( std::exception & ex )
|
{
|
ctx.deactivate();
|
return handle_error_<R>(ctx.tup(), error_info(&ex), std::forward<H>(h)...,
|
[]() -> R { throw; } );
|
}
|
catch(...)
|
{
|
ctx.deactivate();
|
return handle_error_<R>(ctx.tup(), error_info(nullptr), std::forward<H>(h)...,
|
[]() -> R { throw; } );
|
}
|
}
|
}
|
|
template <class TryBlock, class... H>
|
BOOST_LEAF_CONSTEXPR inline
|
typename std::decay<decltype(std::declval<TryBlock>()().value())>::type
|
try_handle_all( TryBlock && try_block, H && ... h )
|
{
|
static_assert(is_result_type<decltype(std::declval<TryBlock>()())>::value, "The return type of the try_block passed to a try_handle_all function must be registered with leaf::is_result_type");
|
context_type_from_handlers<H...> ctx;
|
auto active_context = activate_context(ctx);
|
if( auto r = leaf_detail::try_catch_(
|
ctx,
|
[&]
|
{
|
return std::forward<TryBlock>(try_block)();
|
},
|
std::forward<H>(h)...) )
|
return r.value();
|
else
|
{
|
error_id id = r.error();
|
if( ctx.is_active() )
|
ctx.deactivate();
|
using R = typename std::decay<decltype(std::declval<TryBlock>()().value())>::type;
|
return ctx.template handle_error<R>(std::move(id), std::forward<H>(h)...);
|
}
|
}
|
|
template <class TryBlock, class... H>
|
BOOST_LEAF_NODISCARD BOOST_LEAF_CONSTEXPR inline
|
typename std::decay<decltype(std::declval<TryBlock>()())>::type
|
try_handle_some( TryBlock && try_block, H && ... h )
|
{
|
static_assert(is_result_type<decltype(std::declval<TryBlock>()())>::value, "The return type of the try_block passed to a try_handle_some function must be registered with leaf::is_result_type");
|
context_type_from_handlers<H...> ctx;
|
auto active_context = activate_context(ctx);
|
if( auto r = leaf_detail::try_catch_(
|
ctx,
|
[&]
|
{
|
return std::forward<TryBlock>(try_block)();
|
},
|
std::forward<H>(h)...) )
|
return r;
|
else
|
{
|
error_id id = r.error();
|
if( ctx.is_active() )
|
ctx.deactivate();
|
using R = typename std::decay<decltype(std::declval<TryBlock>()())>::type;
|
auto rr = ctx.template handle_error<R>(std::move(id), std::forward<H>(h)..., [&r]()->R { return std::move(r); });
|
if( !rr )
|
ctx.propagate();
|
return rr;
|
}
|
}
|
|
template <class TryBlock, class... H>
|
BOOST_LEAF_CONSTEXPR inline
|
decltype(std::declval<TryBlock>()())
|
try_catch( TryBlock && try_block, H && ... h )
|
{
|
context_type_from_handlers<H...> ctx;
|
auto active_context = activate_context(ctx);
|
return leaf_detail::try_catch_(
|
ctx,
|
[&]
|
{
|
return std::forward<TryBlock>(try_block)();
|
},
|
std::forward<H>(h)...);
|
}
|
|
#endif
|
|
} }
|
|
// Boost Exception Integration
|
|
namespace boost { class exception; }
|
namespace boost { template <class Tag,class T> class error_info; }
|
namespace boost { namespace exception_detail { template <class ErrorInfo> struct get_info; } }
|
|
namespace boost { namespace leaf {
|
|
namespace leaf_detail
|
{
|
template <class T>
|
struct match_enum_type;
|
|
template <class Tag, class T>
|
struct match_enum_type<boost::error_info<Tag, T>>
|
{
|
using type = T;
|
};
|
|
template <class Ex>
|
BOOST_LEAF_CONSTEXPR inline Ex * get_exception( error_info const & ei )
|
{
|
return dynamic_cast<Ex *>(ei.exception());
|
}
|
|
template <class, class T>
|
struct dependent_type { using type = T; };
|
|
template <class Dep, class T>
|
using dependent_type_t = typename dependent_type<Dep, T>::type;
|
|
template <class Tag, class T>
|
struct handler_argument_traits<boost::error_info<Tag, T>>
|
{
|
using error_type = void;
|
constexpr static bool always_available = false;
|
|
template <class Tup>
|
BOOST_LEAF_CONSTEXPR static T * check( Tup & tup, error_info const & ei ) noexcept
|
{
|
using boost_exception = dependent_type_t<T, boost::exception>;
|
if( auto * be = get_exception<boost_exception>(ei) )
|
return exception_detail::get_info<boost::error_info<Tag, T>>::get(*be);
|
else
|
return 0;
|
}
|
|
template <class Tup>
|
BOOST_LEAF_CONSTEXPR static boost::error_info<Tag, T> get( Tup const & tup, error_info const & ei ) noexcept
|
{
|
return boost::error_info<Tag, T>(*check(tup, ei));
|
}
|
};
|
|
template <class Tag, class T> struct handler_argument_traits<boost::error_info<Tag, T> const &>: handler_argument_traits_require_by_value<boost::error_info<Tag, T>> { };
|
template <class Tag, class T> struct handler_argument_traits<boost::error_info<Tag, T> const *>: handler_argument_traits_require_by_value<boost::error_info<Tag, T>> { };
|
template <class Tag, class T> struct handler_argument_traits<boost::error_info<Tag, T> &>: handler_argument_traits_require_by_value<boost::error_info<Tag, T>> { };
|
template <class Tag, class T> struct handler_argument_traits<boost::error_info<Tag, T> *>: handler_argument_traits_require_by_value<boost::error_info<Tag, T>> { };
|
}
|
|
} }
|
|
#endif
|
