Definition

A state represents what a system (or part of a system) could be doing at any given instant.

The state that represents what the system is currently doing is called the active state.

How to define states with Maki

You don't directly create state objects when using Maki. What you do is create state builder objects and give Maki references to these objects. Eventually, when you instantiate a state machine, Maki creates instances of maki::state with these builders.

A state builder is a constexpr variable of type maki::state_builder (which is actually a class template with plenty of template parameters you don't have to worry about):

constexpr auto my_state = maki::state_builder{};

You can set options through method chaining. Entry and exit actions are examples of such options:

constexpr auto my_state_with_options = maki::state_builder{}
    .entry_action_v([]{std::cout << "Hello\n";})
    .exit_action_v([]{std::cout << "Goodbye\n";});