fsm::row< State, Event, Context, Payload, Reason > Struct Template Reference

One transition-table row: {from, on, when, then, to}. More...

#include <fsm.hpp>

Collaboration diagram for fsm::row< State, Event, Context, Payload, Reason >:

Public Types
using	payload_type = Payload
using	reason_type = Reason
using	guard_fn = typename detail::fn_sigs< Context, Payload >::guard
using	action_fn = typename detail::fn_sigs< Context, Payload >::action

Public Attributes
from_spec< State >	from
	Source state or fsm::any (mandatory).
on_spec< Event >	on
	Trigger event (mandatory).
guard_fn	when = nullptr
	Optional guard.
action_fn	then = nullptr
	Optional action.
target< State, Reason >	to
	Transition/internal/refuse (mandatory).
const char *	label = nullptr

Detailed Description

template<class State, class Event, class Context, class Payload = void, class Reason = uint8_t>
struct fsm::row< State, Event, Context, Payload, Reason >

One transition-table row: {from, on, when, then, to}.

Rows are plain constexpr data: enumerable, dumpable, diagrammable. Matching walks the active state chain leaf → ancestors → fsm::any rows; within a level, table order, first row whose guard passes wins.

Template Parameters

State	state enum (dense, Count sentinel)
Event	event enum (dense, Count sentinel)
Context	user context passed to guards/actions by reference
Payload	optional event payload type (void = none)
Reason	refusal reason type

Member Typedef Documentation

action_fn

template<class State , class Event , class Context , class Payload = void, class Reason = uint8_t>

using fsm::row< State, Event, Context, Payload, Reason >::action_fn = typename detail::fn_sigs<Context, Payload>::action

Transition/internal action. nullptr = none.

guard_fn

template<class State , class Event , class Context , class Payload = void, class Reason = uint8_t>

using fsm::row< State, Event, Context, Payload, Reason >::guard_fn = typename detail::fn_sigs<Context, Payload>::guard

Guard: arbitrary predicate over context (+ payload). nullptr = always pass.

payload_type

template<class State , class Event , class Context , class Payload = void, class Reason = uint8_t>

using fsm::row< State, Event, Context, Payload, Reason >::payload_type = Payload

reason_type

template<class State , class Event , class Context , class Payload = void, class Reason = uint8_t>

using fsm::row< State, Event, Context, Payload, Reason >::reason_type = Reason

Member Data Documentation

from

template<class State , class Event , class Context , class Payload = void, class Reason = uint8_t>

from_spec<State> fsm::row< State, Event, Context, Payload, Reason >::from

Source state or fsm::any (mandatory).

label

template<class State , class Event , class Context , class Payload = void, class Reason = uint8_t>

const char* fsm::row< State, Event, Context, Payload, Reason >::label = nullptr

Optional human-readable note ("why this row exists"), shown by dump() and fsm::write_dot(). Guards/actions are bare function pointers, so this is the only place introspection can find intent.

on

template<class State , class Event , class Context , class Payload = void, class Reason = uint8_t>

on_spec<Event> fsm::row< State, Event, Context, Payload, Reason >::on

Trigger event (mandatory).

then

template<class State , class Event , class Context , class Payload = void, class Reason = uint8_t>

action_fn fsm::row< State, Event, Context, Payload, Reason >::then = nullptr

Optional action.

to

template<class State , class Event , class Context , class Payload = void, class Reason = uint8_t>

target<State, Reason> fsm::row< State, Event, Context, Payload, Reason >::to

Transition/internal/refuse (mandatory).

when

template<class State , class Event , class Context , class Payload = void, class Reason = uint8_t>

guard_fn fsm::row< State, Event, Context, Payload, Reason >::when = nullptr

Optional guard.

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The documentation for this struct was generated from the following file:

• include/fsm/fsm.hpp