From 9690fe0be90455743c8c6e9427b3057c69975d75 Mon Sep 17 00:00:00 2001
From: tyranron <tyranron@gmail.com>
Date: Thu, 25 Jul 2024 12:16:01 +0300
Subject: [PATCH] Simplify

---
 impl/src/fmt/display.rs | 57 +++++++++++++++++++----------------------
 1 file changed, 26 insertions(+), 31 deletions(-)

diff --git a/impl/src/fmt/display.rs b/impl/src/fmt/display.rs
index d58c4622..9e86bd57 100644
--- a/impl/src/fmt/display.rs
+++ b/impl/src/fmt/display.rs
@@ -245,25 +245,24 @@ impl<'a> Expansion<'a> {
     fn generate_body(&self) -> syn::Result<TokenStream> {
         let mut body = TokenStream::new();
 
-        if self
+        // If `shared_attr` is a transparent call, then we consider it being absent.
+        let has_shared_attr = self
             .shared_attr
-            .map_or(true, |a| a.contains_arg("_variant"))
+            .map_or(false, |a| a.transparent_call().is_none());
+
+        if !has_shared_attr
+            || self
+                .shared_attr
+                .map_or(true, |a| a.contains_arg("_variant"))
         {
             body = match &self.attrs.fmt {
                 Some(fmt) => {
-                    if let Some((expr, trait_ident)) = fmt.transparent_call() {
-                        if self.shared_attr.is_some() {
-                            let placeholder =
-                                trait_name_to_default_placeholder_literal(&trait_ident);
-
-                            quote! { &derive_more::core::format_args!(#placeholder, #expr) }
-                        } else {
-                            quote! {
-                                derive_more::core::fmt::#trait_ident::fmt(&(#expr), __derive_more_f)
-                            }
-                        }
-                    } else if self.shared_attr.is_some() {
+                    if has_shared_attr {
                         quote! { &derive_more::core::format_args!(#fmt) }
+                    } else if let Some((expr, trait_ident)) = fmt.transparent_call() {
+                        quote! {
+                            derive_more::core::fmt::#trait_ident::fmt(&(#expr), __derive_more_f)
+                        }
                     } else {
                         quote! { derive_more::core::write!(__derive_more_f, #fmt) }
                     }
@@ -271,7 +270,7 @@ impl<'a> Expansion<'a> {
                 None if self.fields.is_empty() => {
                     let ident_str = self.ident.unraw().to_string();
 
-                    if self.shared_attr.is_some() {
+                    if has_shared_attr {
                         quote! { #ident_str }
                     } else {
                         quote! { __derive_more_f.write_str(#ident_str) }
@@ -287,7 +286,7 @@ impl<'a> Expansion<'a> {
                         field.ident.clone().unwrap_or_else(|| format_ident!("_0"));
                     let trait_ident = self.trait_ident;
 
-                    if self.shared_attr.is_some() {
+                    if has_shared_attr {
                         let placeholder =
                             trait_name_to_default_placeholder_literal(trait_ident);
 
@@ -311,22 +310,18 @@ impl<'a> Expansion<'a> {
             };
         }
 
-        if let Some(shared_fmt) = &self.shared_attr {
-            let shared_body = if let Some((shared_expr, shared_trait_ident)) =
-                shared_fmt.transparent_call()
-            {
-                quote! {
-                    derive_more::core::fmt::#shared_trait_ident::fmt(#shared_expr, __derive_more_f)
-                }
-            } else {
-                quote! { derive_more::core::write!(__derive_more_f, #shared_fmt) }
-            };
+        if has_shared_attr {
+            if let Some(shared_fmt) = &self.shared_attr {
+                let shared_body = quote! {
+                    derive_more::core::write!(__derive_more_f, #shared_fmt)
+                };
 
-            body = if body.is_empty() {
-                shared_body
-            } else {
-                quote! { match #body { _variant => #shared_body } }
-            };
+                body = if body.is_empty() {
+                    shared_body
+                } else {
+                    quote! { match #body { _variant => #shared_body } }
+                }
+            }
         }
 
         Ok(body)