rustdoc: Return String from doc_value, not Option

src/librustdoc/clean/types.rs

@@ -414,7 +414,7 @@ impl Item {
 
     /// Finds the `doc` attribute as a NameValue and returns the corresponding
     /// value found.
-    crate fn doc_value(&self) -> Option<String> {
+    crate fn doc_value(&self) -> String {
         self.attrs.doc_value()
     }
 
@@ -1081,10 +1081,13 @@ impl Attributes {
 
     /// Finds the `doc` attribute as a NameValue and returns the corresponding
     /// value found.
-    crate fn doc_value(&self) -> Option<String> {
+    crate fn doc_value(&self) -> String {
         let mut iter = self.doc_strings.iter();
 
-        let ori = iter.next()?;
+        let ori = match iter.next() {
+            Some(s) => s,
+            None => return String::new(),
+        };
         let mut out = String::new();
         add_doc_fragment(&mut out, ori);
         for new_frag in iter {
@@ -1093,7 +1096,7 @@ impl Attributes {
             }
             add_doc_fragment(&mut out, new_frag);
         }
-        if out.is_empty() { None } else { Some(out) }
+        out
     }
 
     /// Return the doc-comments on this item, grouped by the module they came from.

src/librustdoc/core.rs

@@ -397,7 +397,7 @@ crate fn run_global_ctxt(
 
     let mut krate = tcx.sess.time("clean_crate", || clean::krate(&mut ctxt));
 
-    if krate.module.doc_value().map(|d| d.is_empty()).unwrap_or(true) {
+    if krate.module.doc_value().is_empty() {
         let help = format!(
             "The following guide may be of use:\n\
             {}/rustdoc/how-to-write-documentation.html",

src/librustdoc/formats/cache.rs

@@ -294,9 +294,8 @@ impl<'a, 'tcx> DocFolder for CacheBuilder<'a, 'tcx> {
                     // which should not be indexed. The crate-item itself is
                     // inserted later on when serializing the search-index.
                     if item.def_id.index().map_or(false, |idx| idx != CRATE_DEF_INDEX) {
-                        let desc = item.doc_value().map_or_else(String::new, |x| {
-                            short_markdown_summary(x.as_str(), &item.link_names(self.cache))
-                        });
+                        let desc =
+                            short_markdown_summary(&item.doc_value(), &item.link_names(self.cache));
                         self.cache.search_index.push(IndexItem {
                             ty: item.type_(),
                             name: s.to_string(),

src/librustdoc/html/render/cache.rs

@@ -32,9 +32,7 @@ crate fn build_index<'tcx>(krate: &clean::Crate, cache: &mut Cache, tcx: TyCtxt<
     // has since been learned.
     for &(did, ref item) in &cache.orphan_impl_items {
         if let Some(&(ref fqp, _)) = cache.paths.get(&did) {
-            let desc = item
-                .doc_value()
-                .map_or_else(String::new, |s| short_markdown_summary(&s, &item.link_names(cache)));
+            let desc = short_markdown_summary(&item.doc_value(), &item.link_names(cache));
             cache.search_index.push(IndexItem {
                 ty: item.type_(),
                 name: item.name.unwrap().to_string(),
@@ -48,10 +46,8 @@ crate fn build_index<'tcx>(krate: &clean::Crate, cache: &mut Cache, tcx: TyCtxt<
         }
     }
 
-    let crate_doc = krate
-        .module
-        .doc_value()
-        .map_or_else(String::new, |s| short_markdown_summary(&s, &krate.module.link_names(cache)));
+    let crate_doc =
+        short_markdown_summary(&krate.module.doc_value(), &krate.module.link_names(cache));
 
     let Cache { ref mut search_index, ref paths, .. } = *cache;
 

src/librustdoc/html/render/context.rs

@@ -183,8 +183,8 @@ impl<'tcx> Context<'tcx> {
         };
         title.push_str(" - Rust");
         let tyname = it.type_();
-        let desc = it.doc_value().as_ref().map(|doc| plain_text_summary(doc));
-        let desc = if let Some(desc) = desc {
+        let desc = plain_text_summary(&it.doc_value());
+        let desc = if !desc.is_empty() {
             desc
         } else if it.is_crate() {
             format!("API documentation for the Rust `{}` crate.", self.shared.layout.krate)
@@ -265,10 +265,9 @@ impl<'tcx> Context<'tcx> {
                 Some(ref s) => s.to_string(),
             };
             let short = short.to_string();
-            map.entry(short).or_default().push((
-                myname,
-                Some(item.doc_value().map_or_else(String::new, |s| plain_text_summary(&s))),
-            ));
+            map.entry(short)
+                .or_default()
+                .push((myname, Some(plain_text_summary(&item.doc_value()))));
         }
 
         if self.shared.sort_modules_alphabetically {

src/librustdoc/html/render/mod.rs

@@ -525,10 +525,11 @@ fn document_short(
     if !show_def_docs {
         return;
     }
-    if let Some(s) = item.doc_value() {
-        let mut summary_html = MarkdownSummaryLine(&s, &item.links(cx)).into_string();
+    let dox = &item.doc_value();
+    if !dox.is_empty() {
+        let mut summary_html = MarkdownSummaryLine(dox, &item.links(cx)).into_string();
 
-        if s.contains('\n') {
+        if dox.contains('\n') {
             let link = format!(r#" <a href="{}">Read more</a>"#, naive_assoc_href(item, link, cx));
 
             if let Some(idx) = summary_html.rfind("</p>") {
@@ -1363,7 +1364,7 @@ fn render_impl(
                     if let Some(it) = t.items.iter().find(|i| i.name == item.name) {
                         // We need the stability of the item from the trait
                         // because impls can't have a stability.
-                        if item.doc_value().is_some() {
+                        if !item.doc_value().is_empty() {
                             document_item_info(&mut info_buffer, cx, it, Some(parent));
                             document_full(&mut doc_buffer, item, cx, HeadingOffset::H5);
                             short_documented = false;

src/librustdoc/html/render/print_item.rs

@@ -388,7 +388,7 @@ fn item_module(w: &mut Buffer, cx: &Context<'_>, item: &clean::Item, items: &[cl
                 let stab = myitem.stability_class(cx.tcx());
                 let add = if stab.is_some() { " " } else { "" };
 
-                let doc_value = myitem.doc_value().unwrap_or_default();
+                let doc_value = myitem.doc_value();
                 w.write_str(ITEM_TABLE_ROW_OPEN);
                 write!(
                     w,