Remove generation of unused components of tuple

serde_derive/src/de.rs

@@ -952,17 +952,9 @@ fn deserialize_struct(
 
  let field_names_idents: Vec<_> = fields
  .iter()
- .enumerate()
  // Skip fields that shouldn't be deserialized or that were flattened,
  // so they don't appear in the storage in their literal form
- .filter(|&(_, field)| !field.attrs.skip_deserializing() && !field.attrs.flatten())
- .map(|(i, field)| {
- (
- field.attrs.name().deserialize_name(),
- field_i(i),
- field.attrs.aliases(),
- )
- })
+ .filter(|field| !field.attrs.skip_deserializing() && !field.attrs.flatten())
  .collect();
 
  let has_flatten = has_flatten(fields);
@@ -1026,7 +1018,7 @@ fn deserialize_struct(
  } else {
  let field_names = field_names_idents
  .iter()
- .flat_map(|&(_, _, aliases)| aliases);
+ .flat_map(|field| field.attrs.aliases());
 
  Some(quote! {
  #[doc(hidden)]
@@ -1120,15 +1112,7 @@ fn deserialize_struct_in_place(
 
  let field_names_idents: Vec<_> = fields
  .iter()
- .enumerate()
- .filter(|&(_, field)| !field.attrs.skip_deserializing())
- .map(|(i, field)| {
- (
- field.attrs.name().deserialize_name(),
- field_i(i),
- field.attrs.aliases(),
- )
- })
+ .filter(|field| !field.attrs.skip_deserializing())
  .collect();
 
  let (consts, field, field_seed) = deserialize_field_identifier(&field_names_idents, cattrs, false);
@@ -1144,7 +1128,7 @@ fn deserialize_struct_in_place(
  ));
  let field_names = field_names_idents
  .iter()
- .flat_map(|&(_, _, aliases)| aliases);
+ .flat_map(|field| field.attrs.aliases());
  let type_name = cattrs.name().deserialize_name();
 
  let in_place_impl_generics = de_impl_generics.in_place();
@@ -2054,7 +2038,7 @@ fn deserialize_generated_identifier(
 /// Generates enum and its `Deserialize` implementation that represents each
 /// non-skipped field of the struct
 fn deserialize_field_identifier(
- fields: &[(&str, Ident, &BTreeSet<String>)],
+ fields: &[&Field],
  cattrs: &attr::Container,
  has_flatten: bool,
 ) -> (TokenStream, TokenStream, TokenStream) {
@@ -2075,10 +2059,11 @@ fn deserialize_field_identifier(
  )
  };
 
- // `aliases` also contains a main name
- let aliases = fields
- .iter()
- .map(|(_, _, aliases)| quote!(&[ #(#aliases),* ]));
+ let aliases = fields.iter().map(|field| {
+ // `aliases` also contains a main name
+ let aliases = field.attrs.aliases();
+ quote!(&[ #(#aliases),* ])
+ });
  let consts = quote! {
  #[doc(hidden)]
  const ALIASES: &[&[&str]] = &[ #(#aliases),* ];