Function bytes_size

endian_codec/endian_codec_derive/src/lib.rs:56–97

(data: &Data)

}

fn bytes_size(data: &Data) -> TokenStream {
    match *data {
        Data::Struct(ref data) => {
            match data.fields {
                Fields::Named(ref fields) => {
                    // Expands to an expression like
                    //
                    //     0 + <self.x as PackedSize>::PACKED_LEN + <self.y as PackedSize>::PACKED_LEN
                    let recurse = fields.named.iter().map(|f| {
                        let ty = &f.ty;
                        quote_spanned! {f.span()=>
                            <#ty as PackedSize>::PACKED_LEN
                        }
                    });

                    quote! {
                        0  #(+ #recurse)*
                    }
                }
                Fields::Unnamed(ref fields) => {
                    // Expands to an expression like
                    //
                    //     0 + <self.0 as PackedSize>::PACKED_LEN + <self.1 as PackedSize>::PACKED_LEN
                    let recurse = fields.unnamed.iter().map(|f| {
                        let ty = &f.ty;
                        quote_spanned! {f.span()=>
                            <#ty as PackedSize>::PACKED_LEN
                        }
                    });
                    quote! {
                        0 #(+ #recurse)*
                    }
                }
                Fields::Unit => {
                    // Unit structs cannot own more than 0 bytes of heap memory.
                    quote!(0)
                }
            }
        }
        Data::Enum(_) | Data::Union(_) => unimplemented!(),
    }
}

#[proc_macro_derive(EncodeLE)]
pub fn derive_endian_ser_bytes(input: proc_macro::TokenStream) -> proc_macro::TokenStream {