1use crate::add_like;
2use crate::mul_helpers::generics_and_exprs;
3use crate::utils::{AttrParams, HashSet, MultiFieldData, RefType, State};
4use proc_macro2::TokenStream;
5use quote::{format_ident, quote};
6use std::iter;
7use syn::{DeriveInput, Result};
8
9pub fn expand(input: &DeriveInput, trait_name: &'static str) -> Result<TokenStream> {
10 let mut state = State::with_attr_params(
11 input,
12 trait_name,
13 trait_name.to_lowercase(),
14 AttrParams::struct_(vec!["forward"]),
15 )?;
16 if state.default_info.forward {
17 return Ok(add_like::expand(input, trait_name));
18 }
19
20 let scalar_ident = format_ident!("__RhsT");
21 state.add_trait_path_type_param(quote! { #scalar_ident });
22 let multi_field_data = state.enabled_fields_data();
23 let MultiFieldData {
24 input_type,
25 field_types,
26 ty_generics,
27 trait_path,
28 trait_path_with_params,
29 method_ident,
30 ..
31 } = multi_field_data.clone();
32
33 let tys = field_types.iter().collect::<HashSet<_>>();
34 let tys = tys.iter();
35 let scalar_iter = iter::repeat(&scalar_ident);
36 let trait_path_iter = iter::repeat(trait_path);
37
38 let type_where_clauses = quote! {
39 where #(#tys: #trait_path_iter<#scalar_iter, Output=#tys>),*
40 };
41
42 let (generics, initializers) = generics_and_exprs(
43 multi_field_data.clone(),
44 &scalar_ident,
45 type_where_clauses,
46 RefType::No,
47 );
48 let body = multi_field_data.initializer(&initializers);
49 let (impl_generics, _, where_clause) = generics.split_for_impl();
50 Ok(quote! {
51 #[automatically_derived]
52 impl #impl_generics #trait_path_with_params for #input_type #ty_generics #where_clause {
53 type Output = #input_type #ty_generics;
54
55 #[inline]
56 #[track_caller]
57 fn #method_ident(self, rhs: #scalar_ident) -> #input_type #ty_generics {
58 #body
59 }
60 }
61 })
62}
63