Use `Iterator::eq` and (dogfood) `eq_by` in compiler and library

4 files changed, 7 insertions, 14 deletions

diff --git a/compiler/rustc_builtin_macros/src/autodiff.rs b/compiler/rustc_builtin_macros/src/autodiff.rs
index f4a923797e2..ddc59bfe141 100644
--- a/compiler/rustc_builtin_macros/src/autodiff.rs
+++ b/compiler/rustc_builtin_macros/src/autodiff.rs
@@ -377,8 +377,7 @@ mod llvm_enzyme {
                 (ast::AttrKind::Normal(a), ast::AttrKind::Normal(b)) => {
                     let a = &a.item.path;
                     let b = &b.item.path;
-                    a.segments.len() == b.segments.len()
-                        && a.segments.iter().zip(b.segments.iter()).all(|(a, b)| a.ident == b.ident)
+                    a.segments.iter().eq_by(&b.segments, |a, b| a.ident == b.ident)
                 }
                 _ => false,
             }
diff --git a/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs b/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
index 75db5d77783..5b378de8bbd 100644
--- a/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
@@ -356,21 +356,14 @@ fn contains_maybe_sized_bound(bounds: &[GenericBound]) -> bool {
     bounds.iter().any(is_maybe_sized_bound)
 }
 
-fn path_segment_is_exact_match(path_segments: &[ast::PathSegment], syms: &[Symbol]) -> bool {
-    path_segments.iter().zip(syms).all(|(segment, &symbol)| segment.ident.name == symbol)
-}
-
 fn is_sized_marker(path: &ast::Path) -> bool {
     const CORE_UNSIZE: [Symbol; 3] = [sym::core, sym::marker, sym::Sized];
     const STD_UNSIZE: [Symbol; 3] = [sym::std, sym::marker, sym::Sized];
-    if path.segments.len() == 4 && path.is_global() {
-        path_segment_is_exact_match(&path.segments[1..], &CORE_UNSIZE)
-            || path_segment_is_exact_match(&path.segments[1..], &STD_UNSIZE)
-    } else if path.segments.len() == 3 {
-        path_segment_is_exact_match(&path.segments, &CORE_UNSIZE)
-            || path_segment_is_exact_match(&path.segments, &STD_UNSIZE)
+    let segments = || path.segments.iter().map(|segment| segment.ident.name);
+    if path.is_global() {
+        segments().skip(1).eq(CORE_UNSIZE) || segments().skip(1).eq(STD_UNSIZE)
     } else {
-        *path == sym::Sized
+        segments().eq(CORE_UNSIZE) || segments().eq(STD_UNSIZE) || *path == sym::Sized
     }
 }
 
diff --git a/compiler/rustc_builtin_macros/src/format.rs b/compiler/rustc_builtin_macros/src/format.rs
index d70888205a5..bffc0407e81 100644
--- a/compiler/rustc_builtin_macros/src/format.rs
+++ b/compiler/rustc_builtin_macros/src/format.rs
@@ -768,7 +768,7 @@ fn report_missing_placeholders(
 
     if !found_foreign && invalid_refs.is_empty() {
         // Show example if user didn't use any format specifiers
-        let show_example = used.iter().all(|used| !used);
+        let show_example = !used.contains(&true);
 
         if !show_example {
             if unused.len() > 1 {
diff --git a/compiler/rustc_builtin_macros/src/lib.rs b/compiler/rustc_builtin_macros/src/lib.rs
index 4541e2cd3b4..57cf62ea612 100644
--- a/compiler/rustc_builtin_macros/src/lib.rs
+++ b/compiler/rustc_builtin_macros/src/lib.rs
@@ -11,6 +11,7 @@
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(if_let_guard)]
+#![feature(iter_order_by)]
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_quote)]
 #![feature(rustdoc_internals)]