1 files changed, 28 insertions, 0 deletions
diff --git a/third_party/rust/derive_more-impl/src/add_helpers.rs b/third_party/rust/derive_more-impl/src/add_helpers.rs
new file mode 100644
index 0000000000..b9cee1a682
--- /dev/null
+++ b/third_party/rust/derive_more-impl/src/add_helpers.rs
@@ -0,0 +1,28 @@
+use proc_macro2::TokenStream;
+use quote::quote;
+use syn::{Field, Ident, Index};
+
+pub fn tuple_exprs(fields: &[&Field], method_ident: &Ident) -> Vec<TokenStream> {
+    let mut exprs = vec![];
+
+    for i in 0..fields.len() {
+        let i = Index::from(i);
+        // generates `self.0.add(rhs.0)`
+        let expr = quote! { self.#i.#method_ident(rhs.#i) };
+        exprs.push(expr);
+    }
+    exprs
+}
+
+pub fn struct_exprs(fields: &[&Field], method_ident: &Ident) -> Vec<TokenStream> {
+    let mut exprs = vec![];
+
+    for field in fields {
+        // It's safe to unwrap because struct fields always have an identifier
+        let field_id = field.ident.as_ref().unwrap();
+        // generates `x: self.x.add(rhs.x)`
+        let expr = quote! { self.#field_id.#method_ident(rhs.#field_id) };
+        exprs.push(expr)
+    }
+    exprs
+}