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#ifndef BOOST_LEAF_HANDLE_ERRORS_HPP_INCLUDED
#define BOOST_LEAF_HANDLE_ERRORS_HPP_INCLUDED
// Copyright (c) 2018-2020 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(__clang__)
# pragma clang system_header
# elif (__GNUC__*100+__GNUC_MINOR__>301)
# pragma GCC system_header
# elif defined(_MSC_VER)
# pragma warning(push,1)
# endif
#endif
#include <boost/leaf/context.hpp>
#include <boost/leaf/detail/demangle.hpp>
#ifndef BOOST_LEAF_NO_EXCEPTIONS
# include <boost/leaf/capture.hpp>
#endif
namespace boost { namespace leaf {
class error_info
{
error_info & operator=( error_info const & ) = delete;
#ifndef BOOST_LEAF_NO_EXCEPTIONS
static error_id unpack_error_id( std::exception const * ex ) noexcept
{
if( std::system_error const * se = dynamic_cast<std::system_error const *>(ex) )
if( is_error_id(se->code()) )
return leaf_detail::make_error_id(se->code().value());
if( std::error_code const * ec = dynamic_cast<std::error_code const *>(ex) )
if( is_error_id(*ec) )
return leaf_detail::make_error_id(ec->value());
if( error_id const * err_id = dynamic_cast<error_id const *>(ex) )
return *err_id;
return current_error();
}
std::exception * const ex_;
#endif
error_id const err_id_;
protected:
error_info( error_info const & ) noexcept = default;
template <class CharT, class Traits>
void print( std::basic_ostream<CharT, Traits> & os ) const
{
os << "Error ID = " << err_id_.value();
#ifndef BOOST_LEAF_NO_EXCEPTIONS
if( ex_ )
{
os <<
"\nException dynamic type: " << leaf_detail::demangle(typeid(*ex_).name()) <<
"\nstd::exception::what(): " << ex_->what();
}
#endif
}
public:
BOOST_LEAF_CONSTEXPR explicit error_info( error_id id ) noexcept:
#ifndef BOOST_LEAF_NO_EXCEPTIONS
ex_(0),
#endif
err_id_(id)
{
}
#ifndef BOOST_LEAF_NO_EXCEPTIONS
explicit error_info( std::exception * ex ) noexcept:
ex_(ex),
err_id_(unpack_error_id(ex_))
{
}
#endif
BOOST_LEAF_CONSTEXPR error_id error() const noexcept
{
return err_id_;
}
BOOST_LEAF_CONSTEXPR std::exception * exception() const noexcept
{
#ifdef BOOST_LEAF_NO_EXCEPTIONS
return nullptr;
#else
return ex_;
#endif
}
template <class CharT, class Traits>
friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, error_info const & x )
{
os << "leaf::error_info: ";
x.print(os);
return os << '\n';
}
};
////////////////////////////////////////
#if BOOST_LEAF_DIAGNOSTICS
class diagnostic_info: public error_info
{
leaf_detail::e_unexpected_count const * e_uc_;
void const * tup_;
void (*print_)( std::ostream &, void const * tup, int key_to_print );
protected:
diagnostic_info( diagnostic_info const & ) noexcept = default;
template <class Tup>
BOOST_LEAF_CONSTEXPR diagnostic_info( error_info const & ei, leaf_detail::e_unexpected_count const * e_uc, Tup const & tup ) noexcept:
error_info(ei),
e_uc_(e_uc),
tup_(&tup),
print_(&leaf_detail::tuple_for_each<std::tuple_size<Tup>::value, Tup>::print)
{
}
public:
template <class CharT, class Traits>
friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, diagnostic_info const & x )
{
os << "leaf::diagnostic_info for ";
x.print(os);
os << ":\n";
x.print_(os, x.tup_, x.error().value());
if( x.e_uc_ )
x.e_uc_->print(os);
return os;
}
};
namespace leaf_detail
{
struct diagnostic_info_: diagnostic_info
{
template <class Tup>
BOOST_LEAF_CONSTEXPR diagnostic_info_( error_info const & ei, leaf_detail::e_unexpected_count const * e_uc, Tup const & tup ) noexcept:
diagnostic_info(ei, e_uc, tup)
{
}
};
template <>
struct handler_argument_traits<diagnostic_info const &>: handler_argument_always_available<e_unexpected_count>
{
template <class Tup>
BOOST_LEAF_CONSTEXPR static diagnostic_info_ get( Tup const & tup, error_info const & ei ) noexcept
{
return diagnostic_info_(ei, handler_argument_traits_defaults<e_unexpected_count>::check(tup, ei), tup);
}
};
}
#else
class diagnostic_info: public error_info
{
protected:
diagnostic_info( diagnostic_info const & ) noexcept = default;
BOOST_LEAF_CONSTEXPR diagnostic_info( error_info const & ei ) noexcept:
error_info(ei)
{
}
public:
template <class CharT, class Traits>
friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, diagnostic_info const & x )
{
os <<
"leaf::diagnostic_info requires #define BOOST_LEAF_DIAGNOSTICS 1\n"
"leaf::error_info: ";
x.print(os);
return os << '\n';
}
};
namespace leaf_detail
{
struct diagnostic_info_: diagnostic_info
{
BOOST_LEAF_CONSTEXPR diagnostic_info_( error_info const & ei ) noexcept:
diagnostic_info(ei)
{
}
};
template <>
struct handler_argument_traits<diagnostic_info const &>: handler_argument_always_available<void>
{
template <class Tup>
BOOST_LEAF_CONSTEXPR static diagnostic_info_ get( Tup const & tup, error_info const & ei ) noexcept
{
return diagnostic_info_(ei);
}
};
}
#endif
////////////////////////////////////////
#if BOOST_LEAF_DIAGNOSTICS
class verbose_diagnostic_info: public error_info
{
leaf_detail::e_unexpected_info const * e_ui_;
void const * tup_;
void (*print_)( std::ostream &, void const * tup, int key_to_print );
protected:
verbose_diagnostic_info( verbose_diagnostic_info const & ) noexcept = default;
template <class Tup>
BOOST_LEAF_CONSTEXPR verbose_diagnostic_info( error_info const & ei, leaf_detail::e_unexpected_info const * e_ui, Tup const & tup ) noexcept:
error_info(ei),
e_ui_(e_ui),
tup_(&tup),
print_(&leaf_detail::tuple_for_each<std::tuple_size<Tup>::value, Tup>::print)
{
}
public:
template <class CharT, class Traits>
friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, verbose_diagnostic_info const & x )
{
os << "leaf::verbose_diagnostic_info for ";
x.print(os);
os << ":\n";
x.print_(os, x.tup_, x.error().value());
if( x.e_ui_ )
x.e_ui_->print(os);
return os;
}
};
namespace leaf_detail
{
struct verbose_diagnostic_info_: verbose_diagnostic_info
{
template <class Tup>
BOOST_LEAF_CONSTEXPR verbose_diagnostic_info_( error_info const & ei, leaf_detail::e_unexpected_info const * e_ui, Tup const & tup ) noexcept:
verbose_diagnostic_info(ei, e_ui, tup)
{
}
};
template <>
struct handler_argument_traits<verbose_diagnostic_info const &>: handler_argument_always_available<e_unexpected_info>
{
template <class Tup>
BOOST_LEAF_CONSTEXPR static verbose_diagnostic_info_ get( Tup const & tup, error_info const & ei ) noexcept
{
return verbose_diagnostic_info_(ei, handler_argument_traits_defaults<e_unexpected_info>::check(tup, ei), tup);
}
};
}
#else
class verbose_diagnostic_info: public error_info
{
protected:
verbose_diagnostic_info( verbose_diagnostic_info const & ) noexcept = default;
BOOST_LEAF_CONSTEXPR verbose_diagnostic_info( error_info const & ei ) noexcept:
error_info(ei)
{
}
public:
template <class CharT, class Traits>
friend std::basic_ostream<CharT, Traits> & operator<<( std::basic_ostream<CharT, Traits> & os, verbose_diagnostic_info const & x )
{
os <<
"leaf::verbose_diagnostic_info requires #define BOOST_LEAF_DIAGNOSTICS 1\n"
"leaf::error_info: ";
x.print(os);
return os << '\n';
}
};
namespace leaf_detail
{
struct verbose_diagnostic_info_: verbose_diagnostic_info
{
BOOST_LEAF_CONSTEXPR verbose_diagnostic_info_( error_info const & ei ) noexcept:
verbose_diagnostic_info(ei)
{
}
};
template <>
struct handler_argument_traits<verbose_diagnostic_info const &>: handler_argument_always_available<void>
{
template <class Tup>
BOOST_LEAF_CONSTEXPR static verbose_diagnostic_info_ get( Tup const & tup, error_info const & ei ) noexcept
{
return verbose_diagnostic_info_(ei);
}
};
}
#endif
////////////////////////////////////////
namespace leaf_detail
{
template <class T, class... List>
struct type_index;
template <class T, class... Cdr>
struct type_index<T, T, Cdr...>
{
constexpr static int value = 0;
};
template <class T, class Car, class... Cdr>
struct type_index<T, Car, Cdr...>
{
constexpr static int value = 1 + type_index<T,Cdr...>::value;
};
template <class T, class Tuple>
struct tuple_type_index;
template <class T, class... TupleTypes>
struct tuple_type_index<T,std::tuple<TupleTypes...>>
{
constexpr static int value = type_index<T,TupleTypes...>::value;
};
#ifndef BOOST_LEAF_NO_EXCEPTIONS
template <class E, bool = std::is_class<E>::value>
struct peek_exception;
template <>
struct peek_exception<std::exception const, true>
{
BOOST_LEAF_CONSTEXPR static std::exception const * peek( error_info const & ei ) noexcept
{
return ei.exception();
}
};
template <>
struct peek_exception<std::exception, true>
{
BOOST_LEAF_CONSTEXPR static std::exception * peek( error_info const & ei ) noexcept
{
return ei.exception();
}
};
template <>
struct peek_exception<std::error_code const, true>
{
static std::error_code const * peek( error_info const & ei ) noexcept
{
auto const ex = ei.exception();
if( std::system_error * se = dynamic_cast<std::system_error *>(ex) )
return &se->code();
else if( std::error_code * ec = dynamic_cast<std::error_code *>(ex) )
return ec;
else
return 0;
}
};
template <>
struct peek_exception<std::error_code, true>
{
static std::error_code * peek( error_info const & ei ) noexcept
{
auto const ex = ei.exception();
if( std::system_error * se = dynamic_cast<std::system_error *>(ex) )
return const_cast<std::error_code *>(&se->code());
else if( std::error_code * ec = dynamic_cast<std::error_code *>(ex) )
return ec;
else
return 0;
}
};
template <class E>
struct peek_exception<E, true>
{
static E * peek( error_info const & ei ) noexcept
{
return dynamic_cast<E *>(ei.exception());
}
};
template <class E>
struct peek_exception<E, false>
{
BOOST_LEAF_CONSTEXPR static E * peek( error_info const & ) noexcept
{
return 0;
}
};
#endif
template <class E, class SlotsTuple>
BOOST_LEAF_CONSTEXPR inline
E const *
peek( SlotsTuple const & tup, error_info const & ei ) noexcept
{
if( error_id err = ei.error() )
if( E const * e = std::get<tuple_type_index<slot<E>,SlotsTuple>::value>(tup).has_value(err.value()) )
return e;
#ifndef BOOST_LEAF_NO_EXCEPTIONS
else
return peek_exception<E const>::peek(ei);
#endif
return 0;
}
template <class E, class SlotsTuple>
BOOST_LEAF_CONSTEXPR inline
E *
peek( SlotsTuple & tup, error_info const & ei ) noexcept
{
if( error_id err = ei.error() )
if( E * e = std::get<tuple_type_index<slot<E>,SlotsTuple>::value>(tup).has_value(err.value()) )
return e;
#ifndef BOOST_LEAF_NO_EXCEPTIONS
else
return peek_exception<E>::peek(ei);
#endif
return 0;
}
}
////////////////////////////////////////
namespace leaf_detail
{
template <class A>
template <class Tup>
BOOST_LEAF_CONSTEXPR inline
typename handler_argument_traits_defaults<A, false>::error_type const *
handler_argument_traits_defaults<A, false>::
check( Tup const & tup, error_info const & ei ) noexcept
{
return peek<typename std::decay<A>::type>(tup, ei);
}
template <class A>
template <class Tup>
BOOST_LEAF_CONSTEXPR inline
typename handler_argument_traits_defaults<A, false>::error_type *
handler_argument_traits_defaults<A, false>::
check( Tup & tup, error_info const & ei ) noexcept
{
return peek<typename std::decay<A>::type>(tup, ei);
}
template <class Tup>
BOOST_LEAF_CONSTEXPR inline
std::exception const *
handler_argument_traits<void>::
check( Tup const &, error_info const & ei ) noexcept
{
return ei.exception();
}
template <class Tup, class... List>
struct check_arguments;
template <class Tup>
struct check_arguments<Tup>
{
BOOST_LEAF_CONSTEXPR static bool check( Tup const &, error_info const & )
{
return true;
}
};
template <class Tup, class Car, class... Cdr>
struct check_arguments<Tup, Car, Cdr...>
{
BOOST_LEAF_CONSTEXPR static bool check( Tup & tup, error_info const & ei ) noexcept
{
return handler_argument_traits<Car>::check(tup, ei) && check_arguments<Tup, Cdr...>::check(tup, ei);
}
};
}
////////////////////////////////////////
namespace leaf_detail
{
template <class>
struct handler_matches_any_error: std::false_type
{
};
template <template<class...> class L>
struct handler_matches_any_error<L<>>: std::true_type
{
};
template <template<class...> class L, class Car, class... Cdr>
struct handler_matches_any_error<L<Car, Cdr...>>
{
constexpr static bool value = handler_argument_traits<Car>::always_available && handler_matches_any_error<L<Cdr...>>::value;
};
}
////////////////////////////////////////
namespace leaf_detail
{
template <class Tup, class... A>
BOOST_LEAF_CONSTEXPR inline bool check_handler_( Tup & tup, error_info const & ei, leaf_detail_mp11::mp_list<A...> ) noexcept
{
return check_arguments<Tup, A...>::check(tup, ei);
}
template <class R, class F, bool IsResult = is_result_type<R>::value, class FReturnType = fn_return_type<F>>
struct handler_caller
{
template <class Tup, class... A>
BOOST_LEAF_CONSTEXPR static R call( Tup & tup, error_info const & ei, F && f, leaf_detail_mp11::mp_list<A...> )
{
return std::forward<F>(f)( handler_argument_traits<A>::get(tup, ei)... );
}
};
template <template <class...> class Result, class... E, class F>
struct handler_caller<Result<void, E...>, F, true, void>
{
using R = Result<void, E...>;
template <class Tup, class... A>
BOOST_LEAF_CONSTEXPR static R call( Tup & tup, error_info const & ei, F && f, leaf_detail_mp11::mp_list<A...> )
{
std::forward<F>(f)( handler_argument_traits<A>::get(tup, ei)... );
return { };
}
};
template <class T>
struct is_tuple: std::false_type { };
template <class... T>
struct is_tuple<std::tuple<T...>>: std::true_type { };
template <class... T>
struct is_tuple<std::tuple<T...> &>: std::true_type { };
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 )
{
static_assert( handler_matches_any_error<fn_mp_args<H>>::value, "The last handler passed to handle_all must match any error." );
return handler_caller<R, H>::call( tup, ei, std::forward<H>(h), fn_mp_args<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 )
{
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
return handle_error_<R>( tup, ei, std::forward<Cdr>(cdr)...);
}
template <class R, class Tup, class HTup, size_t ... I>
BOOST_LEAF_CONSTEXPR inline
R
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
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>(
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
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