Attribute Macro document_type_parameters 

#[document_type_parameters]

Generates documentation for type parameters.

This macro analyzes the item’s signature (function, struct, enum, impl block, etc.) and generates a documentation comment list based on the provided descriptions.

When used within a module annotated with #[document_module], it benefits from automatic Self resolution and is applied as part of the module-level documentation pass.

Syntax

#[document_type_parameters(
    "Description for first parameter",
    ("OverriddenName", "Description for second parameter"),
    ...
)]
pub fn function_name<Generics>(params) -> ReturnType { ... }

It can also be used on other items like impl blocks:

#[document_type_parameters("Description for T")]
impl<T> MyType<T> { ... }

Parameters

• Descriptions: A comma-separated list. Each entry can be either a string literal or a tuple of two string literals (Name, Description).

Generates

A list of documentation comments, one for each generic parameter, prepended to the function definition.

Examples

// Invocation
#[document_type_parameters(
    "The type of the elements.",
    ("E", "The error type.")
)]
pub fn map<T, ERR>(...) { ... }

// Expanded code
/// * `T`: The type of the elements.
/// * `E`: The error type.
pub fn map<T, ERR>(...) { ... }

Constraints

• The number of arguments must exactly match the number of generic parameters (including lifetimes, types, and const generics) in the function signature.