Get rid of unnecessary BufDisplay abstraction

Author: yotamofek

src/librustdoc/html/layout.rs

@@ -1,4 +1,4 @@
-use std::fmt::{self, Display};
+use std::fmt::Display;
 use std::path::PathBuf;
 
 use askama::Template;
@@ -71,23 +71,6 @@ struct PageLayout<'a> {
 
 pub(crate) use crate::html::render::sidebar::filters;
 
-/// Implements [`Display`] for a function that accepts a mutable reference to a [`String`], and (optionally) writes to it.
-///
-/// The wrapped function will receive an empty string, and can modify it,
-/// and the `Display` implementation will write the contents of the string after the function has finished.
-pub(crate) struct BufDisplay<F>(pub F);
-
-impl<F> Display for BufDisplay<F>
-where
-    F: Fn(&mut String),
-{
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let mut buf = String::new();
-        self.0(&mut buf);
-        f.write_str(&buf)
-    }
-}
-
 pub(crate) fn render<T: Display, S: Display>(
     layout: &Layout,
     page: &Page<'_>,

src/librustdoc/html/render/context.rs

@@ -28,11 +28,10 @@ use crate::formats::cache::Cache;
 use crate::formats::item_type::ItemType;
 use crate::html::escape::Escape;
 use crate::html::format::join_with_double_colon;
-use crate::html::layout::{self, BufDisplay};
 use crate::html::markdown::{self, ErrorCodes, IdMap, plain_text_summary};
 use crate::html::render::write_shared::write_shared;
 use crate::html::url_parts_builder::UrlPartsBuilder;
-use crate::html::{sources, static_files};
+use crate::html::{layout, sources, static_files};
 use crate::scrape_examples::AllCallLocations;
 use crate::{DOC_RUST_LANG_ORG_VERSION, try_err};
 
@@ -250,9 +249,7 @@ impl<'tcx> Context<'tcx> {
             layout::render(
                 &self.shared.layout,
                 &page,
-                BufDisplay(|buf: &mut String| {
-                    print_sidebar(self, it, buf).unwrap();
-                }),
+                fmt::from_fn(|f| print_sidebar(self, it, f)),
                 content,
                 &self.shared.style_files,
             )

src/librustdoc/html/sources.rs

@@ -11,9 +11,8 @@ use rustc_session::Session;
 use rustc_span::{FileName, FileNameDisplayPreference, RealFileName, sym};
 use tracing::info;
 
-use super::highlight;
-use super::layout::{self, BufDisplay};
 use super::render::Context;
+use super::{highlight, layout};
 use crate::clean;
 use crate::clean::utils::has_doc_flag;
 use crate::docfs::PathError;
@@ -243,17 +242,16 @@ impl SourceCollector<'_, '_> {
             &shared.layout,
             &page,
             "",
-            BufDisplay(|buf: &mut String| {
+            fmt::from_fn(|f| {
                 print_src(
-                    buf,
+                    f,
                     contents,
                     file_span,
                     self.cx,
                     &root_path,
                     &highlight::DecorationInfo::default(),
                     &source_context,
                 )
-                .unwrap();
             }),
             &shared.style_files,
         );