remove extraneous comments

crates/osstr_traits_derive/src/attr_args.rs

@@ -2,9 +2,11 @@ use syn::parse::{Parse, ParseStream};
 use syn::{Expr, Ident, LitStr, Token, custom_keyword};
 
 custom_keyword!(transparent);
+custom_keyword!(from_display);
 
 pub enum OsDisplayAttribute {
     Transparent,
+    FromDisplay,
     Format(FormatArgs),
 }
 
@@ -25,6 +27,13 @@ impl Parse for OsDisplayAttribute {
             } else {
                 Ok(OsDisplayAttribute::Transparent)
             }
+        } else if lookahead.peek(from_display) {
+            input.parse::<from_display>()?;
+            if !input.is_empty() {
+                Err(input.error("Unexpected tokens after `from_display` attribute."))
+            } else {
+                Ok(OsDisplayAttribute::FromDisplay)
+            }
         } else if lookahead.peek(LitStr) {
             let format_string = input.parse()?;
 

crates/osstr_traits_derive/src/lib.rs

@@ -61,6 +61,32 @@ pub fn os_display_derive(input: TokenStream) -> TokenStream {
                                     }
                                 }
                             }
+                            OsDisplayAttribute::FromDisplay => {
+                                match &variant.fields {
+                                    Fields::Unnamed(fields) if fields.unnamed.len() == 1 => {
+                                        quote_spanned! {variant.span() =>
+                                            match self {
+                                                #name::#variant_name(value) => f.write_str(&value.to_string()),
+                                                _ => unreachable!(),
+                                            }
+                                        }
+                                    }
+                                    Fields::Named(fields) if fields.named.len() == 1 => {
+                                        let field_ident = fields.named.first().unwrap().ident.as_ref().unwrap();
+                                        quote_spanned! {variant.span() =>
+                                            match self {
+                                                #name::#variant_name{#field_ident} => f.write_str(&#field_ident.to_string()),
+                                                _ => unreachable!(),
+                                            }
+                                        }
+                                    }
+                                    _ => {
+                                        return quote_spanned! {variant.span() =>
+                                            compile_error!("#[os_display(from_display)] on an enum variant requires a single field which implements std::fmt::Display.");
+                                        };
+                                    }
+                                }
+                            }
                             OsDisplayAttribute::Format(format_args) => {
                                 let format_str_value = format_args.format_string.value();
                                 
@@ -191,6 +217,15 @@ pub fn os_display_derive(input: TokenStream) -> TokenStream {
                             }
                         }
                     }
+                    OsDisplayAttribute::FromDisplay => {
+                        quote! {
+                            impl #impl_generics my_os_traits::OsDisplay for #name #ty_generics #where_clause {
+                                fn fmt_os(&self, f: &mut my_os_traits::OsStringFormatter) -> std::fmt::Result {
+                                    f.write_str(&self.to_string())
+                                }
+                            }
+                        }
+                    }
                     OsDisplayAttribute::Format(format_args) => {
                         let format_str_value = format_args.format_string.value();
                         let positional_expressions: Vec<&Expr> = format_args.positional_args.iter().collect();