diff --git a/serde_derive/src/bound.rs b/serde_derive/src/bound.rs index 4e7c7d71..74d628c5 100644 --- a/serde_derive/src/bound.rs +++ b/serde_derive/src/bound.rs @@ -50,18 +50,29 @@ pub fn with_where_predicates( generics } -pub fn with_where_predicates_from_fields( +pub fn with_where_predicates_from_fields( cont: &Container, generics: &syn::Generics, + trait_bound: &syn::Path, from_field: F, + where_ty: W, ) -> syn::Generics where F: Fn(&attr::Field) -> Option<&[syn::WherePredicate]>, + W: for<'a> Fn(&attr::Field) -> Option<&syn::ExprPath>, { let predicates = cont.data .all_fields() - .flat_map(|field| from_field(&field.attrs)) - .flat_map(|predicates| predicates.to_vec()); + .flat_map(|field| { + let field_bound: Option = match where_ty(&field.attrs) { + Some(_) => None, + None => { + let field_ty = field.ty; + Some(parse_quote!(#field_ty: #trait_bound)) + } + }; + field_bound.into_iter().chain(from_field(&field.attrs).into_iter().flat_map(|predicates| predicates.to_vec())) + }); let mut generics = generics.clone(); generics.make_where_clause() diff --git a/serde_derive/src/de.rs b/serde_derive/src/de.rs index 941c624a..975f95c7 100644 --- a/serde_derive/src/de.rs +++ b/serde_derive/src/de.rs @@ -124,7 +124,9 @@ impl Parameters { fn build_generics(cont: &Container, borrowed: &BorrowedLifetimes) -> syn::Generics { let generics = bound::without_defaults(cont.generics); - let generics = bound::with_where_predicates_from_fields(cont, &generics, attr::Field::de_bound); + let delife = borrowed.de_lifetime(); + let de_bound = parse_quote!(_serde::Deserialize<#delife>); + let generics = bound::with_where_predicates_from_fields(cont, &generics, &de_bound, attr::Field::de_bound, attr::Field::deserialize_with); match cont.attrs.de_bound() { Some(predicates) => bound::with_where_predicates(&generics, predicates), @@ -136,12 +138,11 @@ fn build_generics(cont: &Container, borrowed: &BorrowedLifetimes) -> syn::Generi attr::Default::None | attr::Default::Path(_) => generics, }; - let delife = borrowed.de_lifetime(); let generics = bound::with_bound( cont, &generics, needs_deserialize_bound, - &parse_quote!(_serde::Deserialize<#delife>), + &de_bound, ); bound::with_bound( diff --git a/serde_derive/src/ser.rs b/serde_derive/src/ser.rs index 8bcacd6a..07b88d81 100644 --- a/serde_derive/src/ser.rs +++ b/serde_derive/src/ser.rs @@ -130,8 +130,9 @@ impl Parameters { fn build_generics(cont: &Container) -> syn::Generics { let generics = bound::without_defaults(cont.generics); + let trait_bound = parse_quote!(_serde::Serialize); let generics = - bound::with_where_predicates_from_fields(cont, &generics, attr::Field::ser_bound); + bound::with_where_predicates_from_fields(cont, &generics, &trait_bound, attr::Field::ser_bound, attr::Field::serialize_with); match cont.attrs.ser_bound() { Some(predicates) => bound::with_where_predicates(&generics, predicates), @@ -139,7 +140,7 @@ fn build_generics(cont: &Container) -> syn::Generics { cont, &generics, needs_serialize_bound, - &parse_quote!(_serde::Serialize), + &trait_bound ), } }