TypeFoldable in rustc_infer::infer - Rust
Description: Derives `TypeFoldable` for the annotated `struct` or `enum` (`union` is not supported).

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## TypeFoldable

# Derive Macro TypeFoldable

Source

    #[derive(TypeFoldable)]
    {
        // Attributes available to this derive:
        #[type_foldable]
    }

Expand description

Derives `TypeFoldable` for the annotated `struct` or `enum` (`union` is not supported).

The fold will produce a value of the same struct or enum variant as the input, with each field respectively folded using the `TypeFoldable` implementation for its type. However, if a field of a struct or an enum variant is annotated with `#[type_foldable(identity)]` then that field will retain its incumbent value (and its type is not required to implement `TypeFoldable`).