Design patterns Monostate Monostate-based hierarchies
Example
In contrasto to the Singleton, the Monostate is suitable to be inherited to extend its functionalities, as long as member methods are not static.
It follows a minimal example in C++:
struct Settings {
virtual std::size_t width() const noexcept { return width_; }
virtual std::size_t height() const noexcept { return height_; }
private:
static std::size_t width_;
static std::size_t height_;
};
std::size_t Settings::width_{0};
std::size_t Settings::height_{0};
struct EnlargedSettings: Settings {
std::size_t width() const noexcept override { return Settings::height() + 1; }
std::size_t height() const noexcept override { return Settings::width() + 1; }
};
