derive_more/
mul_assign_like.rs

1use crate::add_assign_like;
2use crate::mul_helpers::generics_and_exprs;
3use crate::utils::{AttrParams, MultiFieldData, RefType, State};
4use proc_macro2::{Span, TokenStream};
5use quote::quote;
6use std::collections::HashSet;
7use std::iter;
8use syn::{DeriveInput, Ident, Result};
9
10pub fn expand(input: &DeriveInput, trait_name: &'static str) -> Result<TokenStream> {
11    let method_name = trait_name
12        .to_lowercase()
13        .trim_end_matches("assign")
14        .to_string()
15        + "_assign";
16
17    let mut state = State::with_attr_params(
18        input,
19        trait_name,
20        quote!(::core::ops),
21        method_name,
22        AttrParams::struct_(vec!["forward"]),
23    )?;
24    if state.default_info.forward {
25        return Ok(add_assign_like::expand(input, trait_name));
26    }
27    let scalar_ident = &Ident::new("__RhsT", Span::call_site());
28    state.add_trait_path_type_param(quote!(#scalar_ident));
29    let multi_field_data = state.enabled_fields_data();
30    let MultiFieldData {
31        input_type,
32        field_types,
33        ty_generics,
34        trait_path,
35        trait_path_with_params,
36        method_ident,
37        ..
38    } = multi_field_data.clone();
39
40    let tys = field_types.iter().collect::<HashSet<_>>();
41    let tys = tys.iter();
42    let trait_path_iter = iter::repeat(trait_path_with_params);
43
44    let type_where_clauses = quote! {
45        where #(#tys: #trait_path_iter),*
46    };
47
48    let (generics, exprs) = generics_and_exprs(
49        multi_field_data.clone(),
50        scalar_ident,
51        type_where_clauses,
52        RefType::Mut,
53    );
54    let (impl_generics, _, where_clause) = generics.split_for_impl();
55
56    Ok(quote!(
57        impl#impl_generics #trait_path<#scalar_ident> for #input_type#ty_generics #where_clause{
58            #[inline]
59            fn #method_ident(&mut self, rhs: #scalar_ident) {
60                #(#exprs;
61                  )*
62            }
63        }
64    ))
65}
derive_more/mul_assign_like.rs

derive_more/
mul_assign_like.rs
