From 4e8199b572f2035b7749cba276ece3a26630d23e Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:18:21 +0200 Subject: Adding upstream version 1.67.1+dfsg1. Signed-off-by: Daniel Baumann --- vendor/derive_more/src/index.rs | 50 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 vendor/derive_more/src/index.rs (limited to 'vendor/derive_more/src/index.rs') diff --git a/vendor/derive_more/src/index.rs b/vendor/derive_more/src/index.rs new file mode 100644 index 000000000..5aea59769 --- /dev/null +++ b/vendor/derive_more/src/index.rs @@ -0,0 +1,50 @@ +use crate::utils::{add_where_clauses_for_new_ident, SingleFieldData, State}; +use proc_macro2::{Span, TokenStream}; +use quote::quote; +use syn::{parse::Result, DeriveInput, Ident}; + +/// Provides the hook to expand `#[derive(Index)]` into an implementation of `Index` +pub fn expand(input: &DeriveInput, trait_name: &'static str) -> Result { + let index_type = &Ident::new("__IdxT", Span::call_site()); + let mut state = State::with_field_ignore( + input, + trait_name, + quote!(::core::ops), + trait_name.to_lowercase(), + )?; + state.add_trait_path_type_param(quote!(#index_type)); + let SingleFieldData { + field, + field_type, + input_type, + trait_path_with_params, + casted_trait, + member, + .. + } = state.assert_single_enabled_field(); + + let type_where_clauses = quote! { + where #field_type: #trait_path_with_params + }; + + let new_generics = add_where_clauses_for_new_ident( + &input.generics, + &[field], + index_type, + type_where_clauses, + true, + ); + + let (impl_generics, _, where_clause) = new_generics.split_for_impl(); + let (_, ty_generics, _) = input.generics.split_for_impl(); + Ok(quote! { + impl#impl_generics #trait_path_with_params for #input_type#ty_generics #where_clause + { + type Output = #casted_trait::Output; + #[inline] + fn index(&self, idx: #index_type) -> &Self::Output { + #casted_trait::index(&#member, idx) + } + } + }) +} -- cgit v1.2.3