diff --git a/compiler/rustc_errors/src/json.rs b/compiler/rustc_errors/src/json.rs
index 6a3f8ca497a57..c1188665a05f4 100644
--- a/compiler/rustc_errors/src/json.rs
+++ b/compiler/rustc_errors/src/json.rs
@@ -463,7 +463,8 @@ impl DiagnosticSpan {
         // is an empty string, increase the length to include the newline so we don't
         // leave an empty line
         if start.col.0 == 0
-            && suggestion.is_some_and(|(s, _)| s.is_empty())
+            && let Some((suggestion, _)) = suggestion
+            && suggestion.is_empty()
             && let Ok(after) = je.sm.span_to_next_source(span)
             && after.starts_with('\n')
         {
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 6e5958a20d0b9..549729548f537 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -35,6 +35,7 @@ use std::backtrace::{Backtrace, BacktraceStatus};
 use std::borrow::Cow;
 use std::cell::Cell;
 use std::error::Report;
+use std::ffi::OsStr;
 use std::hash::Hash;
 use std::io::Write;
 use std::num::NonZero;
@@ -1717,7 +1718,7 @@ impl DiagCtxtInner {
         let bugs: Vec<_> =
             std::mem::take(&mut self.delayed_bugs).into_iter().map(|(b, _)| b).collect();
 
-        let backtrace = std::env::var_os("RUST_BACKTRACE").is_none_or(|x| &x != "0");
+        let backtrace = std::env::var_os("RUST_BACKTRACE").as_deref() != Some(OsStr::new("0"));
         let decorate = backtrace || self.ice_file.is_none();
         let mut out = self
             .ice_file
diff --git a/compiler/rustc_metadata/src/creader.rs b/compiler/rustc_metadata/src/creader.rs
index 586b38ff14443..a6db12f893255 100644
--- a/compiler/rustc_metadata/src/creader.rs
+++ b/compiler/rustc_metadata/src/creader.rs
@@ -417,7 +417,8 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
         // Any descendants of `std` should be private. These crates are usually not marked
         // private in metadata, so we ignore that field.
         if extern_private.is_none()
-            && dep_root.is_some_and(|d| STDLIB_STABLE_CRATES.contains(&d.name))
+            && let Some(dep) = dep_root
+            && STDLIB_STABLE_CRATES.contains(&dep.name)
         {
             return true;
         }
diff --git a/compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs b/compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs
index ab4d59185a52b..78196b0536190 100644
--- a/compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs
+++ b/compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs
@@ -97,7 +97,7 @@ impl<Prov: Provenance> ProvenanceMap<Prov> {
         debug_assert!(prov.len() <= 1);
         if let Some(entry) = prov.first() {
             // If it overlaps with this byte, it is on this byte.
-            debug_assert!(self.bytes.as_ref().is_none_or(|b| b.get(&offset).is_none()));
+            debug_assert!(self.bytes.as_ref().is_none_or(|b| !b.contains_key(&offset)));
             Some(entry.1)
         } else {
             // Look up per-byte provenance.
diff --git a/compiler/rustc_middle/src/ty/diagnostics.rs b/compiler/rustc_middle/src/ty/diagnostics.rs
index 77745599afb92..e4187d2760c3d 100644
--- a/compiler/rustc_middle/src/ty/diagnostics.rs
+++ b/compiler/rustc_middle/src/ty/diagnostics.rs
@@ -336,7 +336,7 @@ pub fn suggest_constraining_type_params<'a>(
             .collect();
 
         constraints
-            .retain(|(_, def_id, _)| def_id.map_or(true, |def| !bound_trait_defs.contains(&def)));
+            .retain(|(_, def_id, _)| def_id.is_none_or(|def| !bound_trait_defs.contains(&def)));
 
         if constraints.is_empty() {
             continue;
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 9cd93817b4ce5..e9d0fc04c1363 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -675,7 +675,7 @@ impl OutputTypes {
 
     /// Returns `true` if user specified a name and not just produced type
     pub fn contains_explicit_name(&self, key: &OutputType) -> bool {
-        self.0.get(key).is_some_and(|f| f.is_some())
+        matches!(self.0.get(key), Some(Some(..)))
     }
 
     pub fn iter(&self) -> BTreeMapIter<'_, OutputType, Option<OutFileName>> {
@@ -1951,7 +1951,7 @@ fn collect_print_requests(
     matches: &getopts::Matches,
 ) -> Vec<PrintRequest> {
     let mut prints = Vec::<PrintRequest>::new();
-    if cg.target_cpu.as_ref().is_some_and(|s| s == "help") {
+    if cg.target_cpu.as_deref() == Some("help") {
         prints.push(PrintRequest { kind: PrintKind::TargetCPUs, out: OutFileName::Stdout });
         cg.target_cpu = None;
     };
diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/static_impl_trait.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/static_impl_trait.rs
index 33603ea66dbc3..503090b579716 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/static_impl_trait.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/static_impl_trait.rs
@@ -420,7 +420,8 @@ fn make_elided_region_spans_suggs<'a>(
 
     let mut process_consecutive_brackets =
         |span: Option<Span>, spans_suggs: &mut Vec<(Span, String)>| {
-            if span.is_some_and(|span| bracket_span.is_none_or(|bracket_span| span == bracket_span))
+            if let Some(span) = span
+                && bracket_span.is_none_or(|bracket_span| span == bracket_span)
             {
                 consecutive_brackets += 1;
             } else if let Some(bracket_span) = bracket_span.take() {