Attribute Macro despatma::abstract_factory

#[abstract_factory]

Turns a trait into an Abstract Factory. The trait can optionally have super-traits.

This macro is generally used with the interpolate_traits macro.

Example input

A factory method needs to be defined to use this macro. The factory method is passed as the first argument to the macro. The rest of the arguments passed to the macro are the elements the factory will create.

use despatma::abstract_factory;

// A factory method
// `Element` is a trait defined by you.
pub trait Factory<T: Element + ?Sized> {
    fn create(&self, name: String) -> Box<T>;
}

// The abstract factory that also needs to implement `Display` and `Eq`.
// The factory method above (`Factory`) is the first input.
#[abstract_factory(Factory, dyn Button, dyn Scroller, dyn Window)]
pub trait GuiFactory: Display + Eq {}

Output

This will create the following code

use despatma::abstract_factory;

// A factory method
// `Element` is a trait defined by you.
pub trait Factory<T: Element + ?Sized> {
    fn create(&self, name: String) -> Box<T>;
}

// The abstract factory that also needs to implement `Display` and `Eq`.
// The factory method above (`Factory`) is the first input.
#[abstract_factory(Factory, dyn Button, dyn Scroller, dyn Window)]
pub trait GuiFactory:
    Display
    + Eq
    + Factory<dyn Button>
    + Factory<dyn Scroller>
    + Factory<dyn Window>
{
}