Function generate_fields

zeroize_derive/src/lib.rs:328–392

(input: &DeriveInput, method: TokenStream)

}

fn generate_fields(input: &DeriveInput, method: TokenStream) -> TokenStream {
    let input_id = &input.ident;
    let fields: Vec<_> = match input.data {
        Data::Enum(ref enum_) => enum_
            .variants
            .iter()
            .filter_map(|variant| {
                if attr_skip(&variant.attrs) {
                    assert!(
                        !variant.fields.iter().any(|field| attr_skip(&field.attrs)),
                        "duplicate #[zeroize] skip flags"
                    );
                    None
                } else {
                    let variant_id = &variant.ident;
                    Some((quote! { #input_id :: #variant_id }, &variant.fields))
                }
            })
            .collect(),
        Data::Struct(ref struct_) => vec![(quote! { #input_id }, &struct_.fields)],
        Data::Union(ref union_) => panic!("Cannot generate fields for untagged union {union_:?}"),
    };

    let arms = fields.into_iter().map(|(name, fields)| {
        let method_field = fields.iter().enumerate().filter_map(|(n, field)| {
            if attr_skip(&field.attrs) {
                None
            } else {
                let name = field_ident(n, field);
                Some(quote! { #name.#method() })
            }
        });

        let field_bindings = fields
            .iter()
            .enumerate()
            .map(|(n, field)| field_ident(n, field));

        let binding = match fields {
            Fields::Named(_) => quote! {
                #name { #(#field_bindings),* }
            },
            Fields::Unnamed(_) => quote! {
                #name ( #(#field_bindings),* )
            },
            Fields::Unit => quote! {
                #name
            },
        };

        quote! {
            #[allow(unused_variables, unused_assignments)]
            #binding => {
                #(#method_field);*
            }
        }
    });