1 files changed, 83 insertions, 0 deletions
diff --git a/vendor/derive_more/src/as_ref.rs b/vendor/derive_more/src/as_ref.rs
new file mode 100644
index 000000000..4b8ba851d
--- /dev/null
+++ b/vendor/derive_more/src/as_ref.rs
@@ -0,0 +1,83 @@
+use crate::utils::{
+    add_where_clauses_for_new_ident, AttrParams, MultiFieldData, State,
+};
+use proc_macro2::{Span, TokenStream};
+use quote::quote;
+use syn::{parse::Result, DeriveInput, Ident};
+
+pub fn expand(input: &DeriveInput, trait_name: &'static str) -> Result<TokenStream> {
+    let as_ref_type = &Ident::new("__AsRefT", Span::call_site());
+    let state = State::with_type_bound(
+        input,
+        trait_name,
+        quote!(::core::convert),
+        String::from("as_ref"),
+        AttrParams::ignore_and_forward(),
+        false,
+    )?;
+    let MultiFieldData {
+        fields,
+        input_type,
+        members,
+        infos,
+        trait_path,
+        impl_generics,
+        ty_generics,
+        where_clause,
+        ..
+    } = state.enabled_fields_data();
+    let sub_items: Vec<_> = infos
+        .iter()
+        .zip(members.iter())
+        .zip(fields)
+        .map(|((info, member), field)| {
+            let field_type = &field.ty;
+            if info.forward {
+                let trait_path = quote!(#trait_path<#as_ref_type>);
+                let type_where_clauses = quote! {
+                    where #field_type: #trait_path
+                };
+                let new_generics = add_where_clauses_for_new_ident(
+                    &input.generics,
+                    &[field],
+                    as_ref_type,
+                    type_where_clauses,
+                    false,
+                );
+                let (impl_generics, _, where_clause) = new_generics.split_for_impl();
+                let casted_trait = quote!(<#field_type as #trait_path>);
+                (
+                    quote!(#casted_trait::as_ref(&#member)),
+                    quote!(#impl_generics),
+                    quote!(#where_clause),
+                    quote!(#trait_path),
+                    quote!(#as_ref_type),
+                )
+            } else {
+                (
+                    quote!(&#member),
+                    quote!(#impl_generics),
+                    quote!(#where_clause),
+                    quote!(#trait_path<#field_type>),
+                    quote!(#field_type),
+                )
+            }
+        })
+        .collect();
+    let bodies = sub_items.iter().map(|i| &i.0);
+    let impl_generics = sub_items.iter().map(|i| &i.1);
+    let where_clauses = sub_items.iter().map(|i| &i.2);
+    let trait_paths = sub_items.iter().map(|i| &i.3);
+    let return_types = sub_items.iter().map(|i| &i.4);
+
+    Ok(quote! {#(
+        impl#impl_generics #trait_paths for #input_type#ty_generics
+        #where_clauses
+        {
+            #[inline]
+            fn as_ref(&self) -> &#return_types {
+                #bodies
+            }
+        }
+    )*})
+}