Macro Apply 

Apply!() { /* proc-macro */ }

Applies a brand to type arguments.

This macro projects a brand type to its concrete type using the appropriate Kind trait. It uses a syntax that mimics a fully qualified path, where the Kind trait is specified by its signature.

InferableBrand!(SIG) invocations within the brand position are resolved automatically via preprocessing, enabling readable signatures like: Apply!(<<FA as InferableBrand!(type Of<'a, A: 'a>: 'a;)>::Brand as Kind!(...)>::Of<'a, B>)

Syntax

Apply!(<Brand as Kind!( KindSignature )>::AssocType<Args>)

• Brand: The brand type (e.g., OptionBrand). May contain InferableBrand!(SIG) invocations.
• KindSignature: A list of associated type definitions defining the Kind trait schema.
• AssocType: The associated type to project (e.g., Of).
• Args: The concrete arguments to apply.

Generates

The concrete type resulting from applying the brand to the arguments.

Examples

// Invocation
// Applies MyBrand to lifetime 'static and type String.
type Concrete = Apply!(<MyBrand as Kind!( type Of<'a, T>; )>::Of<'static, String>);

// Expanded code
type Concrete = <MyBrand as Kind_...>::Of<'static, String>;

// Invocation
// Applies MyBrand to a generic type T with bounds.
type Concrete = Apply!(<MyBrand as Kind!( type Of<T: Clone>; )>::Of<T>);

// Expanded code
type Concrete = <MyBrand as Kind_...>::Of<T>;

// Invocation
// Complex example with lifetimes, types, and output bounds.
type Concrete = Apply!(<MyBrand as Kind!( type Of<'a, T: Clone + Debug>: Display; )>::Of<'a, T>);

// Expanded code
type Concrete = <MyBrand as Kind_...>::Of<'a, T>;

// Invocation
// Use a custom associated type for projection.
type Concrete = Apply!(<MyBrand as Kind!( type Of<T>; type SendOf<T>; )>::SendOf<T>);

// Expanded code
type Concrete = <MyBrand as Kind_...>::SendOf<T>;

// InferableBrand! in the brand position (resolved via preprocessing)
Apply!(<<FA as InferableBrand!(type Of<'a, A: 'a>: 'a;)>::Brand as Kind!(type Of<'a, T: 'a>: 'a;)>::Of<'a, B>)

// Expanded code (InferableBrand! resolved to InferableBrand_cdc7...)
<FA as InferableBrand_cdc7...>::Brand as Kind_cdc7...>::Of<'a, B>