472 lines
15 KiB
C++
472 lines
15 KiB
C++
#ifndef BOOST_LEAF_CONTEXT_HPP_INCLUDED
|
|
#define BOOST_LEAF_CONTEXT_HPP_INCLUDED
|
|
|
|
// Copyright 2018-2022 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)
|
|
|
|
#include <boost/leaf/config.hpp>
|
|
#include <boost/leaf/error.hpp>
|
|
|
|
#if !defined(BOOST_LEAF_NO_THREADS) && !defined(NDEBUG)
|
|
# include <thread>
|
|
#endif
|
|
|
|
namespace boost { namespace leaf {
|
|
|
|
class error_info;
|
|
class diagnostic_info;
|
|
class verbose_diagnostic_info;
|
|
|
|
template <class>
|
|
struct is_predicate: std::false_type
|
|
{
|
|
};
|
|
|
|
namespace leaf_detail
|
|
{
|
|
template <class T>
|
|
struct is_exception: std::is_base_of<std::exception, typename std::decay<T>::type>
|
|
{
|
|
};
|
|
|
|
template <class E>
|
|
struct handler_argument_traits;
|
|
|
|
template <class E, bool IsPredicate = is_predicate<E>::value>
|
|
struct handler_argument_traits_defaults;
|
|
|
|
template <class E>
|
|
struct handler_argument_traits_defaults<E, false>
|
|
{
|
|
using error_type = typename std::decay<E>::type;
|
|
constexpr static bool always_available = false;
|
|
|
|
template <class Tup>
|
|
BOOST_LEAF_CONSTEXPR static error_type const * check( Tup const &, error_info const & ) noexcept;
|
|
|
|
template <class Tup>
|
|
BOOST_LEAF_CONSTEXPR static error_type * check( Tup &, error_info const & ) noexcept;
|
|
|
|
template <class Tup>
|
|
BOOST_LEAF_CONSTEXPR static E get( Tup & tup, error_info const & ei ) noexcept
|
|
{
|
|
return *check(tup, ei);
|
|
}
|
|
|
|
static_assert(!is_predicate<error_type>::value, "Handlers must take predicate arguments by value");
|
|
static_assert(!std::is_same<E, error_info>::value, "Handlers must take leaf::error_info arguments by const &");
|
|
static_assert(!std::is_same<E, diagnostic_info>::value, "Handlers must take leaf::diagnostic_info arguments by const &");
|
|
static_assert(!std::is_same<E, verbose_diagnostic_info>::value, "Handlers must take leaf::verbose_diagnostic_info arguments by const &");
|
|
};
|
|
|
|
template <class Pred>
|
|
struct handler_argument_traits_defaults<Pred, true>: handler_argument_traits<typename Pred::error_type>
|
|
{
|
|
using base = handler_argument_traits<typename Pred::error_type>;
|
|
static_assert(!base::always_available, "Predicates can't use types that are always_available");
|
|
|
|
template <class Tup>
|
|
BOOST_LEAF_CONSTEXPR static bool check( Tup const & tup, error_info const & ei ) noexcept
|
|
{
|
|
auto e = base::check(tup, ei);
|
|
return e && Pred::evaluate(*e);
|
|
}
|
|
|
|
template <class Tup>
|
|
BOOST_LEAF_CONSTEXPR static Pred get( Tup const & tup, error_info const & ei ) noexcept
|
|
{
|
|
return Pred{*base::check(tup, ei)};
|
|
}
|
|
};
|
|
|
|
template <class E>
|
|
struct handler_argument_always_available
|
|
{
|
|
using error_type = E;
|
|
constexpr static bool always_available = true;
|
|
|
|
template <class Tup>
|
|
BOOST_LEAF_CONSTEXPR static bool check( Tup &, error_info const & ) noexcept
|
|
{
|
|
return true;
|
|
}
|
|
};
|
|
|
|
template <class E>
|
|
struct handler_argument_traits: handler_argument_traits_defaults<E>
|
|
{
|
|
};
|
|
|
|
template <>
|
|
struct handler_argument_traits<void>
|
|
{
|
|
using error_type = void;
|
|
constexpr static bool always_available = false;
|
|
|
|
template <class Tup>
|
|
BOOST_LEAF_CONSTEXPR static std::exception const * check( Tup const &, error_info const & ) noexcept;
|
|
};
|
|
|
|
template <class E>
|
|
struct handler_argument_traits<E &&>
|
|
{
|
|
static_assert(sizeof(E) == 0, "Error handlers may not take rvalue ref arguments");
|
|
};
|
|
|
|
template <class E>
|
|
struct handler_argument_traits<E *>: handler_argument_always_available<typename std::remove_const<E>::type>
|
|
{
|
|
template <class Tup>
|
|
BOOST_LEAF_CONSTEXPR static E * get( Tup & tup, error_info const & ei) noexcept
|
|
{
|
|
return handler_argument_traits_defaults<E>::check(tup, ei);
|
|
}
|
|
};
|
|
|
|
template <>
|
|
struct handler_argument_traits<error_info const &>: handler_argument_always_available<void>
|
|
{
|
|
template <class Tup>
|
|
BOOST_LEAF_CONSTEXPR static error_info const & get( Tup const &, error_info const & ei ) noexcept
|
|
{
|
|
return ei;
|
|
}
|
|
};
|
|
|
|
template <class E>
|
|
struct handler_argument_traits_require_by_value
|
|
{
|
|
static_assert(sizeof(E) == 0, "Error handlers must take this type by value");
|
|
};
|
|
}
|
|
|
|
////////////////////////////////////////
|
|
|
|
namespace leaf_detail
|
|
{
|
|
template <int I, class Tuple>
|
|
struct tuple_for_each
|
|
{
|
|
BOOST_LEAF_CONSTEXPR static void activate( Tuple & tup ) noexcept
|
|
{
|
|
static_assert(!std::is_same<error_info, typename std::decay<decltype(std::get<I-1>(tup))>::type>::value, "Bug in LEAF: context type deduction");
|
|
tuple_for_each<I-1,Tuple>::activate(tup);
|
|
std::get<I-1>(tup).activate();
|
|
}
|
|
|
|
BOOST_LEAF_CONSTEXPR static void deactivate( Tuple & tup ) noexcept
|
|
{
|
|
static_assert(!std::is_same<error_info, typename std::decay<decltype(std::get<I-1>(tup))>::type>::value, "Bug in LEAF: context type deduction");
|
|
std::get<I-1>(tup).deactivate();
|
|
tuple_for_each<I-1,Tuple>::deactivate(tup);
|
|
}
|
|
|
|
BOOST_LEAF_CONSTEXPR static void propagate( Tuple & tup, int err_id ) noexcept
|
|
{
|
|
static_assert(!std::is_same<error_info, typename std::decay<decltype(std::get<I-1>(tup))>::type>::value, "Bug in LEAF: context type deduction");
|
|
auto & sl = std::get<I-1>(tup);
|
|
sl.propagate(err_id);
|
|
tuple_for_each<I-1,Tuple>::propagate(tup, err_id);
|
|
}
|
|
|
|
BOOST_LEAF_CONSTEXPR static void propagate_captured( Tuple & tup, int err_id ) noexcept
|
|
{
|
|
static_assert(!std::is_same<error_info, typename std::decay<decltype(std::get<I-1>(tup))>::type>::value, "Bug in LEAF: context type deduction");
|
|
BOOST_LEAF_ASSERT(err_id != 0);
|
|
auto & sl = std::get<I-1>(tup);
|
|
if( sl.has_value(err_id) )
|
|
load_slot(err_id, std::move(sl).value(err_id));
|
|
tuple_for_each<I-1,Tuple>::propagate_captured(tup, err_id);
|
|
}
|
|
|
|
template <class CharT, class Traits>
|
|
static void print( std::basic_ostream<CharT, Traits> & os, void const * tup, int key_to_print )
|
|
{
|
|
BOOST_LEAF_ASSERT(tup != nullptr);
|
|
tuple_for_each<I-1,Tuple>::print(os, tup, key_to_print);
|
|
std::get<I-1>(*static_cast<Tuple const *>(tup)).print(os, key_to_print);
|
|
}
|
|
};
|
|
|
|
template <class Tuple>
|
|
struct tuple_for_each<0, Tuple>
|
|
{
|
|
BOOST_LEAF_CONSTEXPR static void activate( Tuple & ) noexcept { }
|
|
BOOST_LEAF_CONSTEXPR static void deactivate( Tuple & ) noexcept { }
|
|
BOOST_LEAF_CONSTEXPR static void propagate( Tuple &, int ) noexcept { }
|
|
BOOST_LEAF_CONSTEXPR static void propagate_captured( Tuple &, int ) noexcept { }
|
|
template <class CharT, class Traits>
|
|
BOOST_LEAF_CONSTEXPR static void print( std::basic_ostream<CharT, Traits> &, void const *, int ) { }
|
|
};
|
|
}
|
|
|
|
////////////////////////////////////////////
|
|
|
|
#if BOOST_LEAF_CFG_DIAGNOSTICS
|
|
|
|
namespace leaf_detail
|
|
{
|
|
template <class T> struct requires_unexpected { constexpr static bool value = false; };
|
|
template <class T> struct requires_unexpected<T const> { constexpr static bool value = requires_unexpected<T>::value; };
|
|
template <class T> struct requires_unexpected<T const &> { constexpr static bool value = requires_unexpected<T>::value; };
|
|
template <class T> struct requires_unexpected<T const *> { constexpr static bool value = requires_unexpected<T>::value; };
|
|
template <> struct requires_unexpected<e_unexpected_count> { constexpr static bool value = true; };
|
|
template <> struct requires_unexpected<e_unexpected_info> { constexpr static bool value = true; };
|
|
|
|
template <class L>
|
|
struct unexpected_requested;
|
|
|
|
template <template <class ...> class L>
|
|
struct unexpected_requested<L<>>
|
|
{
|
|
constexpr static bool value = false;
|
|
};
|
|
|
|
template <template <class...> class L, template <class> class S, class Car, class... Cdr>
|
|
struct unexpected_requested<L<S<Car>, S<Cdr>...>>
|
|
{
|
|
constexpr static bool value = requires_unexpected<Car>::value || unexpected_requested<L<S<Cdr>...>>::value;
|
|
};
|
|
}
|
|
|
|
#endif
|
|
|
|
////////////////////////////////////////////
|
|
|
|
namespace leaf_detail
|
|
{
|
|
template <class T> struct does_not_participate_in_context_deduction: std::is_abstract<T> { };
|
|
template <> struct does_not_participate_in_context_deduction<void>: std::true_type { };
|
|
template <> struct does_not_participate_in_context_deduction<error_id>: std::true_type { };
|
|
|
|
template <class L>
|
|
struct deduce_e_type_list;
|
|
|
|
template <template<class...> class L, class... T>
|
|
struct deduce_e_type_list<L<T...>>
|
|
{
|
|
using type =
|
|
leaf_detail_mp11::mp_remove_if<
|
|
leaf_detail_mp11::mp_unique<
|
|
leaf_detail_mp11::mp_list<typename handler_argument_traits<T>::error_type...>
|
|
>,
|
|
does_not_participate_in_context_deduction
|
|
>;
|
|
};
|
|
|
|
template <class L>
|
|
struct deduce_e_tuple_impl;
|
|
|
|
template <template <class...> class L, class... E>
|
|
struct deduce_e_tuple_impl<L<E...>>
|
|
{
|
|
using type = std::tuple<slot<E>...>;
|
|
};
|
|
|
|
template <class... E>
|
|
using deduce_e_tuple = typename deduce_e_tuple_impl<typename deduce_e_type_list<leaf_detail_mp11::mp_list<E...>>::type>::type;
|
|
}
|
|
|
|
////////////////////////////////////////////
|
|
|
|
template <class... E>
|
|
class context
|
|
{
|
|
context( context const & ) = delete;
|
|
context & operator=( context const & ) = delete;
|
|
|
|
using Tup = leaf_detail::deduce_e_tuple<E...>;
|
|
Tup tup_;
|
|
bool is_active_;
|
|
|
|
#if !defined(BOOST_LEAF_NO_THREADS) && !defined(NDEBUG)
|
|
std::thread::id thread_id_;
|
|
#endif
|
|
|
|
protected:
|
|
|
|
BOOST_LEAF_CONSTEXPR error_id propagate_captured_errors( error_id err_id ) noexcept
|
|
{
|
|
leaf_detail::tuple_for_each<std::tuple_size<Tup>::value,Tup>::propagate_captured(tup_, err_id.value());
|
|
return err_id;
|
|
}
|
|
|
|
public:
|
|
|
|
BOOST_LEAF_CONSTEXPR context( context && x ) noexcept:
|
|
tup_(std::move(x.tup_)),
|
|
is_active_(false)
|
|
{
|
|
BOOST_LEAF_ASSERT(!x.is_active());
|
|
}
|
|
|
|
BOOST_LEAF_CONSTEXPR context() noexcept:
|
|
is_active_(false)
|
|
{
|
|
}
|
|
|
|
~context() noexcept
|
|
{
|
|
BOOST_LEAF_ASSERT(!is_active());
|
|
}
|
|
|
|
BOOST_LEAF_CONSTEXPR Tup const & tup() const noexcept
|
|
{
|
|
return tup_;
|
|
}
|
|
|
|
BOOST_LEAF_CONSTEXPR Tup & tup() noexcept
|
|
{
|
|
return tup_;
|
|
}
|
|
|
|
BOOST_LEAF_CONSTEXPR void activate() noexcept
|
|
{
|
|
using namespace leaf_detail;
|
|
BOOST_LEAF_ASSERT(!is_active());
|
|
tuple_for_each<std::tuple_size<Tup>::value,Tup>::activate(tup_);
|
|
#if BOOST_LEAF_CFG_DIAGNOSTICS
|
|
if( unexpected_requested<Tup>::value )
|
|
tls::uint32_increment<tls_tag_unexpected_enabled_counter>();
|
|
#endif
|
|
#if !defined(BOOST_LEAF_NO_THREADS) && !defined(NDEBUG)
|
|
thread_id_ = std::this_thread::get_id();
|
|
#endif
|
|
is_active_ = true;
|
|
}
|
|
|
|
BOOST_LEAF_CONSTEXPR void deactivate() noexcept
|
|
{
|
|
using namespace leaf_detail;
|
|
BOOST_LEAF_ASSERT(is_active());
|
|
is_active_ = false;
|
|
#if !defined(BOOST_LEAF_NO_THREADS) && !defined(NDEBUG)
|
|
BOOST_LEAF_ASSERT(std::this_thread::get_id() == thread_id_);
|
|
thread_id_ = std::thread::id();
|
|
#endif
|
|
#if BOOST_LEAF_CFG_DIAGNOSTICS
|
|
if( unexpected_requested<Tup>::value )
|
|
tls::uint32_decrement<tls_tag_unexpected_enabled_counter>();
|
|
#endif
|
|
tuple_for_each<std::tuple_size<Tup>::value,Tup>::deactivate(tup_);
|
|
}
|
|
|
|
BOOST_LEAF_CONSTEXPR void propagate(error_id id) noexcept
|
|
{
|
|
BOOST_LEAF_ASSERT(!is_active());
|
|
leaf_detail::tuple_for_each<std::tuple_size<Tup>::value,Tup>::propagate(tup_, id.value());
|
|
}
|
|
|
|
BOOST_LEAF_CONSTEXPR bool is_active() const noexcept
|
|
{
|
|
return is_active_;
|
|
}
|
|
|
|
template <class CharT, class Traits>
|
|
void print( std::basic_ostream<CharT, Traits> & os ) const
|
|
{
|
|
leaf_detail::tuple_for_each<std::tuple_size<Tup>::value,Tup>::print(os, &tup_, 0);
|
|
}
|
|
|
|
template <class R, class... H>
|
|
BOOST_LEAF_CONSTEXPR R handle_error( error_id, H && ... ) const;
|
|
|
|
template <class R, class... H>
|
|
BOOST_LEAF_CONSTEXPR R handle_error( error_id, H && ... );
|
|
};
|
|
|
|
////////////////////////////////////////
|
|
|
|
namespace leaf_detail
|
|
{
|
|
template <class TypeList>
|
|
struct deduce_context_impl;
|
|
|
|
template <template <class...> class L, class... E>
|
|
struct deduce_context_impl<L<E...>>
|
|
{
|
|
using type = context<E...>;
|
|
};
|
|
|
|
template <class TypeList>
|
|
using deduce_context = typename deduce_context_impl<TypeList>::type;
|
|
|
|
template <class H>
|
|
struct fn_mp_args_fwd
|
|
{
|
|
using type = fn_mp_args<H>;
|
|
};
|
|
|
|
template <class... H>
|
|
struct fn_mp_args_fwd<std::tuple<H...> &>: fn_mp_args_fwd<std::tuple<H...>> { };
|
|
|
|
template <class... H>
|
|
struct fn_mp_args_fwd<std::tuple<H...> const &>: fn_mp_args_fwd<std::tuple<H...>> { };
|
|
|
|
template <class... H>
|
|
struct fn_mp_args_fwd<std::tuple<H...>>
|
|
{
|
|
using type = leaf_detail_mp11::mp_append<typename fn_mp_args_fwd<H>::type...>;
|
|
};
|
|
|
|
template <class... H>
|
|
struct context_type_from_handlers_impl
|
|
{
|
|
using type = deduce_context<leaf_detail_mp11::mp_append<typename fn_mp_args_fwd<H>::type...>>;
|
|
};
|
|
|
|
template <class Ctx>
|
|
struct polymorphic_context_impl: polymorphic_context, Ctx
|
|
{
|
|
error_id propagate_captured_errors() noexcept final override { return Ctx::propagate_captured_errors(captured_id_); }
|
|
void activate() noexcept final override { Ctx::activate(); }
|
|
void deactivate() noexcept final override { Ctx::deactivate(); }
|
|
void propagate(error_id id) noexcept final override { Ctx::propagate(id); }
|
|
bool is_active() const noexcept final override { return Ctx::is_active(); }
|
|
#if BOOST_LEAF_CFG_DIAGNOSTICS
|
|
void print( std::ostream & os ) const final override { return Ctx::print(os); }
|
|
#endif
|
|
};
|
|
}
|
|
|
|
template <class... H>
|
|
using context_type_from_handlers = typename leaf_detail::context_type_from_handlers_impl<H...>::type;
|
|
|
|
////////////////////////////////////////////
|
|
|
|
template <class... H>
|
|
BOOST_LEAF_CONSTEXPR inline context_type_from_handlers<H...> make_context() noexcept
|
|
{
|
|
return { };
|
|
}
|
|
|
|
template <class... H>
|
|
BOOST_LEAF_CONSTEXPR inline context_type_from_handlers<H...> make_context( H && ... ) noexcept
|
|
{
|
|
return { };
|
|
}
|
|
|
|
////////////////////////////////////////////
|
|
|
|
#if BOOST_LEAF_CFG_CAPTURE
|
|
|
|
template <class... H>
|
|
inline context_ptr make_shared_context() noexcept
|
|
{
|
|
return std::make_shared<leaf_detail::polymorphic_context_impl<context_type_from_handlers<H...>>>();
|
|
}
|
|
|
|
template <class... H>
|
|
inline context_ptr make_shared_context( H && ... ) noexcept
|
|
{
|
|
return std::make_shared<leaf_detail::polymorphic_context_impl<context_type_from_handlers<H...>>>();
|
|
}
|
|
|
|
#endif
|
|
|
|
} }
|
|
|
|
#endif
|