Rollup merge of #109846 - matthiaskrgr:clippy2023_04_III, r=Nilstrieb

more clippy::complexity fixes (iter_kv_map, map_flatten, nonminimal_bool)

Author: Noratrieb

compiler/rustc_codegen_llvm/src/common.rs

@@ -378,8 +378,7 @@ pub(crate) fn get_dllimport<'tcx>(
     name: &str,
 ) -> Option<&'tcx DllImport> {
     tcx.native_library(id)
-        .map(|lib| lib.dll_imports.iter().find(|di| di.name.as_str() == name))
-        .flatten()
+        .and_then(|lib| lib.dll_imports.iter().find(|di| di.name.as_str() == name))
 }
 
 pub(crate) fn is_mingw_gnu_toolchain(target: &Target) -> bool {

compiler/rustc_const_eval/src/transform/validate.rs

@@ -677,8 +677,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                     );
                 }
                 if let Rvalue::CopyForDeref(place) = rvalue {
-                    if !place.ty(&self.body.local_decls, self.tcx).ty.builtin_deref(true).is_some()
-                    {
+                    if place.ty(&self.body.local_decls, self.tcx).ty.builtin_deref(true).is_none() {
                         self.fail(
                             location,
                             "`CopyForDeref` should only be used for dereferenceable types",

compiler/rustc_hir_analysis/src/astconv/errors.rs

@@ -483,8 +483,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 [segment] if segment.args.is_none() => {
                     trait_bound_spans = vec![segment.ident.span];
                     associated_types = associated_types
-                        .into_iter()
-                        .map(|(_, items)| (segment.ident.span, items))
+                        .into_values()
+                        .map(|items| (segment.ident.span, items))
                         .collect();
                 }
                 _ => {}

compiler/rustc_hir_typeck/src/expr_use_visitor.rs

@@ -559,7 +559,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
                 // struct; however, when EUV is run during typeck, it
                 // may not. This will generate an error earlier in typeck,
                 // so we can just ignore it.
-                if !self.tcx().sess.has_errors().is_some() {
+                if self.tcx().sess.has_errors().is_none() {
                     span_bug!(with_expr.span, "with expression doesn't evaluate to a struct");
                 }
             }

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -978,7 +978,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             let (_, sig, reg) = ty::print::FmtPrinter::new(self.tcx, Namespace::TypeNS)
                 .name_all_regions(sig)
                 .unwrap();
-            let lts: Vec<String> = reg.into_iter().map(|(_, kind)| kind.to_string()).collect();
+            let lts: Vec<String> = reg.into_values().map(|kind| kind.to_string()).collect();
             (if lts.is_empty() { String::new() } else { format!("for<{}> ", lts.join(", ")) }, sig)
         };
 

compiler/rustc_middle/src/middle/mod.rs

@@ -19,7 +19,7 @@ pub mod lib_features {
                 .stable
                 .iter()
                 .map(|(f, (s, _))| (*f, Some(*s)))
-                .chain(self.unstable.iter().map(|(f, _)| (*f, None)))
+                .chain(self.unstable.keys().map(|f| (*f, None)))
                 .collect();
             all_features.sort_unstable_by(|a, b| a.0.as_str().partial_cmp(b.0.as_str()).unwrap());
             all_features

compiler/rustc_middle/src/ty/consts/valtree.rs

@@ -79,7 +79,7 @@ impl<'tcx> ValTree<'tcx> {
     }
 
     pub fn try_to_target_usize(self, tcx: TyCtxt<'tcx>) -> Option<u64> {
-        self.try_to_scalar_int().map(|s| s.try_to_target_usize(tcx).ok()).flatten()
+        self.try_to_scalar_int().and_then(|s| s.try_to_target_usize(tcx).ok())
     }
 
     /// Get the values inside the ValTree as a slice of bytes. This only works for

compiler/rustc_mir_build/src/build/expr/as_constant.rs

@@ -62,21 +62,21 @@ pub fn as_constant_inner<'tcx>(
             Constant { span, user_ty: None, literal }
         }
         ExprKind::NonHirLiteral { lit, ref user_ty } => {
-            let user_ty = user_ty.as_ref().map(push_cuta).flatten();
+            let user_ty = user_ty.as_ref().and_then(push_cuta);
 
             let literal = ConstantKind::Val(ConstValue::Scalar(Scalar::Int(lit)), ty);
 
             Constant { span, user_ty, literal }
         }
         ExprKind::ZstLiteral { ref user_ty } => {
-            let user_ty = user_ty.as_ref().map(push_cuta).flatten();
+            let user_ty = user_ty.as_ref().and_then(push_cuta);
 
             let literal = ConstantKind::Val(ConstValue::ZeroSized, ty);
 
             Constant { span, user_ty, literal }
         }
         ExprKind::NamedConst { def_id, substs, ref user_ty } => {
-            let user_ty = user_ty.as_ref().map(push_cuta).flatten();
+            let user_ty = user_ty.as_ref().and_then(push_cuta);
 
             let uneval = mir::UnevaluatedConst::new(ty::WithOptConstParam::unknown(def_id), substs);
             let literal = ConstantKind::Unevaluated(uneval, ty);

compiler/rustc_monomorphize/src/partitioning/default.rs

@@ -89,10 +89,7 @@ impl<'tcx> Partitioner<'tcx> for DefaultPartitioning {
         }
 
         PreInliningPartitioning {
-            codegen_units: codegen_units
-                .into_iter()
-                .map(|(_, codegen_unit)| codegen_unit)
-                .collect(),
+            codegen_units: codegen_units.into_values().map(|codegen_unit| codegen_unit).collect(),
             roots,
             internalization_candidates,
         }

compiler/rustc_passes/src/entry.rs

@@ -206,7 +206,7 @@ fn no_main_err(tcx: TyCtxt<'_>, visitor: &EntryContext<'_>) {
     // The file may be empty, which leads to the diagnostic machinery not emitting this
     // note. This is a relatively simple way to detect that case and emit a span-less
     // note instead.
-    let file_empty = !tcx.sess.source_map().lookup_line(sp.hi()).is_ok();
+    let file_empty = tcx.sess.source_map().lookup_line(sp.hi()).is_err();
 
     tcx.sess.emit_err(NoMainErr {
         sp,