Method paths for 18 closures that only call a method (SonarCloud S1612)

SonarCloud's analysis of main at b4da59f0c lists 23 closures such as `|v| v.as_slice()` that hand their argument straight to one method. This passes the method itself: `Vec::as_slice`, `str::to_ascii_lowercase`, `f64::total_cmp` and the like, all forms the repo already uses elsewhere. Behaviour is unchanged.

Five stay. The four in crates/proof/src/es/mod.rs sit in code that #4191 replaces, and its replacement already uses `PoisonError::into_inner`. In crates/engine/src/io/safe_save.rs the path would be `<dyn std::error::Error + Send + Sync>::is::<Guided>`, which reads worse than `|inner| inner.is::<Guided>()`.

apps/wordcraft/src/file_dialogs.rs

@@ -208,7 +208,7 @@ fn save_exts(name: &str) -> Vec<String> {
     let suggested = std::path::Path::new(name)
         .extension()
         .and_then(std::ffi::OsStr::to_str)
-        .map(|e| e.to_ascii_lowercase())
+        .map(str::to_ascii_lowercase)
         .filter(|e| wordcraft_engine::io::SAVE_EXTS.contains(&e.as_str()))
         .unwrap_or_else(|| "docx".to_string());
     let mut exts: Vec<String> = Vec::with_capacity(wordcraft_engine::io::SAVE_EXTS.len());

crates/doc/src/cjk_numbers.rs

@@ -238,7 +238,7 @@ pub(crate) fn ideograph_zodiac_traditional(n: u32) -> String {
 
 /// The `n`th (1-based) item of a sequence, or decimal past its end.
 fn nth(set: &[char], n: u32) -> String {
-    n.checked_sub(1).and_then(|i| set.get(i as usize)).map(|c| c.to_string()).unwrap_or_else(|| n.to_string())
+    n.checked_sub(1).and_then(|i| set.get(i as usize)).map(ToString::to_string).unwrap_or_else(|| n.to_string())
 }
 
 /// Code points `first..` enclosing 1 to `count`, decimal beyond.

crates/docbin/src/piece.rs

@@ -113,7 +113,7 @@ impl PieceTable {
             }
             PrmRef::Sprm0 { isprm, val: (p.prm >> 8) as u8 }
         } else {
-            PrmRef::Grpprl(self.prc_grpprls.get((p.prm >> 1) as usize).map(|v| v.as_slice()))
+            PrmRef::Grpprl(self.prc_grpprls.get((p.prm >> 1) as usize).map(Vec::as_slice))
         }
     }
 

crates/docx/src/read/story.rs

@@ -2291,7 +2291,7 @@ fn css_string(v: &str) -> String {
                 out.push(d);
             }
             // One whitespace after the escape is its terminator, not part of the value.
-            if chars.clone().next().is_some_and(|w| w.is_whitespace()) {
+            if chars.clone().next().is_some_and(char::is_whitespace) {
                 chars.next();
             }
         }

crates/docx/src/write/embed.rs

@@ -68,7 +68,7 @@ impl<'d> EmbedWriter<'d> {
             "[content_types].xml",
         ]
         .iter()
-        .map(|s| s.to_string())
+        .map(ToString::to_string)
         .collect();
         taken.insert(VBA_PROJECT_PART.to_ascii_lowercase());
         // The bibliography writer uses these names when sources are present (#532).

crates/fonts/src/fontdb.rs

@@ -1243,7 +1243,7 @@ impl FontDb {
                     stack.push(p);
                     continue;
                 }
-                let ext = p.extension().and_then(std::ffi::OsStr::to_str).map(|e| e.to_ascii_lowercase());
+                let ext = p.extension().and_then(std::ffi::OsStr::to_str).map(str::to_ascii_lowercase);
                 if !matches!(ext.as_deref(), Some("ttf" | "otf" | "ttc" | "otc")) {
                     continue;
                 }

crates/fonts/src/ui_fallback.rs

@@ -182,7 +182,7 @@ pub(crate) fn find_ui_font(dirs: &[std::path::PathBuf], names: &[&str], needed:
         if !tried.insert(path.clone()) {
             continue;
         }
-        let Some(size) = std::fs::metadata(&path).ok().filter(|m| m.is_file()).map(|m| m.len()) else { continue };
+        let Some(size) = std::fs::metadata(&path).ok().filter(std::fs::Metadata::is_file).map(|m| m.len()) else { continue };
         if size > MAX_FILE {
             continue;
         }

crates/formats/src/odt.rs

@@ -440,7 +440,7 @@ impl Writer {
     /// Paragraph `p`, or with `chain` the paragraphs joined at deleted paragraph marks (`p`
     /// is the first).
     fn para_in(&mut self, p: &Para, chain: Option<&Vec<Para>>, out: &mut String) {
-        let paras: &[Para] = chain.map(|c| c.as_slice()).unwrap_or(std::slice::from_ref(p));
+        let paras: &[Para] = chain.map(Vec::as_slice).unwrap_or(std::slice::from_ref(p));
         let start = self.master.take();
         self.chain = chain.map(|c| c.iter().map(|q| self.para_style(q)).collect()).unwrap_or_default();
         self.part = 0;

crates/layout/src/lib.rs

@@ -1304,7 +1304,7 @@ fn layout_box(
                     let float_y = if float.v_rel == Anchor::Paragraph { para_top } else { y };
                     let r = float_rect(frame, (0.0, width), float_y, w, h, float);
                     let outline = ctx.wrap_outline(o);
-                    excl.extend(wrap_area(r, float, outline.as_deref().map(|v| v.as_slice())));
+                    excl.extend(wrap_area(r, float, outline.as_deref().map(Vec::as_slice)));
                     floats.insert(oi, r);
                 }
                 let rel = rel_exclusions(&excl, 0.0, y);
@@ -3045,8 +3045,8 @@ impl PageFrame<'_> {
     /// Alignment `a` across the page: inside and outside become right and left on an even page.
     fn h_align(frame: Option<&Self>, a: Option<FloatAlign>) -> Option<FloatAlign> {
         match a {
-            Some(FloatAlign::Inside) if frame.is_some_and(|f| f.even()) => Some(FloatAlign::End),
-            Some(FloatAlign::Outside) if frame.is_some_and(|f| f.even()) => Some(FloatAlign::Start),
+            Some(FloatAlign::Inside) if frame.is_some_and(Self::even) => Some(FloatAlign::End),
+            Some(FloatAlign::Outside) if frame.is_some_and(Self::even) => Some(FloatAlign::Start),
             a => a,
         }
     }
@@ -3365,7 +3365,7 @@ fn anchor_floats(
             // Positions relative to the paragraph start above its space before (Word for Windows).
             let mut r = float_rect(Some(frame), (col_x, width), y0 - before, w, h, float);
             let outline = ctx.wrap_outline(o);
-            let outline = outline.as_deref().map(|v| v.as_slice());
+            let outline = outline.as_deref().map(Vec::as_slice);
             let mut area = wrap_area(r, float, outline);
             if pb.settle && text_before {
                 let seed = early.and_then(|v| v.iter().find(|(b, k, _)| (*b, *k) == (block, oi))).map(|(_, _, a)| a);

crates/layout/src/math.rs

@@ -1518,7 +1518,7 @@ impl Ctx {
             }
             segs_rows.push(segs.into_iter().map(hcat).collect());
         }
-        let ncols = segs_rows.iter().map(|r| r.len()).max().unwrap_or(1);
+        let ncols = segs_rows.iter().map(Vec::len).max().unwrap_or(1);
         // Rows without `&` are centred below, so they don't widen the aligned columns.
         let mut col_w = vec![0.0f32; ncols];
         let mut lone_w = 0.0f32;
@@ -1829,7 +1829,7 @@ impl Ctx {
             }
             cells.push(row);
         }
-        let ncols = cells.iter().map(|r| r.len()).max().unwrap_or(0);
+        let ncols = cells.iter().map(Vec::len).max().unwrap_or(0);
         let mut col_w = vec![0.0f32; ncols];
         for r in &cells {
             for (i, b) in r.iter().enumerate() {

crates/metafile/src/geom.rs

@@ -103,7 +103,7 @@ pub(crate) fn subpaths(pts: &[P], counts: &[usize], close: bool) -> Vec<Op> {
     let mut at = 0usize;
     for &c in counts {
         let end = at.saturating_add(c).min(pts.len());
-        let Some((first, rest)) = pts.get(at..end).and_then(|s| s.split_first()) else {
+        let Some((first, rest)) = pts.get(at..end).and_then(<[_]>::split_first) else {
             at = end;
             continue;
         };

crates/proof/src/affix.rs

@@ -419,7 +419,7 @@ impl AffixDict {
             }
             stems.push((word, flags));
         }
-        AffixDict::build(rules, stems, comments.iter().map(|s| s.to_string()).collect())
+        AffixDict::build(rules, stems, comments.iter().map(ToString::to_string).collect())
     }
 
     fn build(rules: Rules, mut stems: Vec<(String, String)>, comments: Vec<String>) -> Result<AffixDict, String> {

crates/ui-egui/examples/perf_probe.rs

@@ -27,7 +27,7 @@ fn step(h: &mut egui_kittest::Harness<'_, WordApp>) -> f64 {
 
 fn stats(v: &[f64]) -> serde_json::Value {
     let mut s = v.to_vec();
-    s.sort_by(|a, b| a.total_cmp(b));
+    s.sort_by(f64::total_cmp);
     let at = |q: f64| s.get(((s.len() as f64 - 1.0) * q).round() as usize).copied().unwrap_or(0.0);
     json!({"n": s.len(), "med": (at(0.5) * 10.0).round() / 10.0, "p95": (at(0.95) * 10.0).round() / 10.0, "max": (at(1.0) * 10.0).round() / 10.0})
 }

xtask/src/layers.rs

@@ -192,7 +192,7 @@ pub fn check(crates: &[Crate]) -> Vec<Violation> {
             }
         }
     }
-    out.sort_by_key(|v| v.to_string());
+    out.sort_by_key(ToString::to_string);
     out.dedup();
     out
 }