diff options
Diffstat (limited to 'vendor/derive_more/src/deref_mut.rs')
-rw-r--r-- | vendor/derive_more/src/deref_mut.rs | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/vendor/derive_more/src/deref_mut.rs b/vendor/derive_more/src/deref_mut.rs new file mode 100644 index 000000000..85d65121b --- /dev/null +++ b/vendor/derive_more/src/deref_mut.rs @@ -0,0 +1,48 @@ +use crate::utils::{add_extra_where_clauses, SingleFieldData, State}; +use proc_macro2::TokenStream; +use quote::quote; +use syn::{parse::Result, DeriveInput}; + +/// Provides the hook to expand `#[derive(DerefMut)]` into an implementation of `DerefMut` +pub fn expand(input: &DeriveInput, trait_name: &'static str) -> Result<TokenStream> { + let state = State::with_field_ignore_and_forward( + input, + trait_name, + quote!(::core::ops), + String::from("deref_mut"), + )?; + let SingleFieldData { + input_type, + trait_path, + casted_trait, + ty_generics, + field_type, + member, + info, + .. + } = state.assert_single_enabled_field(); + let (body, generics) = if info.forward { + ( + quote!(#casted_trait::deref_mut(&mut #member)), + add_extra_where_clauses( + &input.generics, + quote! { + where #field_type: #trait_path + }, + ), + ) + } else { + (quote!(&mut #member), input.generics.clone()) + }; + let (impl_generics, _, where_clause) = generics.split_for_impl(); + + Ok(quote! { + impl#impl_generics #trait_path for #input_type#ty_generics #where_clause + { + #[inline] + fn deref_mut(&mut self) -> &mut Self::Target { + #body + } + } + }) +} |