live_cells::Cell Concept Reference

Defines the cell protocol. More...

#include <types.hpp>

Concept definition

template<typename T>
concept live_cells::Cell =  requires(const T &o) {
        { o.add_observer(observer::ref()) };
        { o.remove_observer(observer::ref()) };
        { o.value() } -> std::same_as<typename T::value_type>;
        { o() } -> std::same_as<typename T::value_type>;
        { o.key() } -> std::same_as<key_ref>;
    }

Detailed Description

Defines the cell protocol.

Cells must define the following types:

• value_type

  The type of value held by the observable.

Cell types must the following methods:

• void add_observer(observer::ref o) const;

  Add observer o to this cell.

• void remove_observer(observer::ref o) const;

  Remove observer o from this cell.

  Implementations should only remove o after this method is called the same number of times as add_observer() was called with the same observer o.

• value_type value() const;

  Return the value held by the observable.

• value_type operator()() const;

  Track this cell as a dependency and return its value.

• key_ref key() const;

  Return a key that uniquely identifies the observable.