use impl IntoIterator for multipart_suggestion and friends

Author: Lukas Markeffsky

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -710,17 +710,14 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         };
 
         let Some(borrow_level) = borrow_level else { return false; };
-        let sugg = move_sites
-            .iter()
-            .map(|move_site| {
-                let move_out = self.move_data.moves[(*move_site).moi];
-                let moved_place = &self.move_data.move_paths[move_out.path].place;
-                let move_spans = self.move_spans(moved_place.as_ref(), move_out.source);
-                let move_span = move_spans.args_or_use();
-                let suggestion = borrow_level.ref_prefix_str().to_owned();
-                (move_span.shrink_to_lo(), suggestion)
-            })
-            .collect();
+        let sugg = move_sites.iter().map(|move_site| {
+            let move_out = self.move_data.moves[(*move_site).moi];
+            let moved_place = &self.move_data.move_paths[move_out.path].place;
+            let move_spans = self.move_spans(moved_place.as_ref(), move_out.source);
+            let move_span = move_spans.args_or_use();
+            let suggestion = borrow_level.ref_prefix_str().to_owned();
+            (move_span.shrink_to_lo(), suggestion)
+        });
         err.multipart_suggestion_verbose(
             format!("consider {}borrowing {value_name}", borrow_level.mutably_str()),
             sugg,

compiler/rustc_builtin_macros/src/deriving/default.rs

@@ -140,16 +140,13 @@ fn extract_default_variant<'a>(
             diag.note("only one variant can be default");
             for variant in &default_variants {
                 // Suggest making each variant already tagged default.
-                let suggestion = default_variants
-                    .iter()
-                    .filter_map(|v| {
-                        if v.span == variant.span {
-                            None
-                        } else {
-                            Some((cx.sess.find_by_name(&v.attrs, kw::Default)?.span, String::new()))
-                        }
-                    })
-                    .collect();
+                let suggestion = default_variants.iter().filter_map(|v| {
+                    if v.span == variant.span {
+                        None
+                    } else {
+                        Some((cx.sess.find_by_name(&v.attrs, kw::Default)?.span, String::new()))
+                    }
+                });
 
                 diag.tool_only_multipart_suggestion(
                     &format!("make `{}` default", variant.ident),
@@ -211,7 +208,7 @@ fn validate_default_attribute(
                 // repetitive `.span_help` call above.
                 .tool_only_multipart_suggestion(
                     suggestion_text,
-                    rest.iter().map(|attr| (attr.span, String::new())).collect(),
+                    rest.iter().map(|attr| (attr.span, String::new())),
                     Applicability::MachineApplicable,
                 )
                 .emit();

compiler/rustc_errors/src/diagnostic.rs

@@ -595,7 +595,7 @@ impl Diagnostic {
     pub fn multipart_suggestion(
         &mut self,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestion: Vec<(Span, String)>,
+        suggestion: impl IntoIterator<Item = (Span, String)>,
         applicability: Applicability,
     ) -> &mut Self {
         self.multipart_suggestion_with_style(
@@ -611,7 +611,7 @@ impl Diagnostic {
     pub fn multipart_suggestion_verbose(
         &mut self,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestion: Vec<(Span, String)>,
+        suggestion: impl IntoIterator<Item = (Span, String)>,
         applicability: Applicability,
     ) -> &mut Self {
         self.multipart_suggestion_with_style(
@@ -625,7 +625,7 @@ impl Diagnostic {
     pub fn multipart_suggestion_with_style(
         &mut self,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestion: Vec<(Span, String)>,
+        suggestion: impl IntoIterator<Item = (Span, String)>,
         applicability: Applicability,
         style: SuggestionStyle,
     ) -> &mut Self {
@@ -666,7 +666,7 @@ impl Diagnostic {
     pub fn tool_only_multipart_suggestion(
         &mut self,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestion: Vec<(Span, String)>,
+        suggestion: impl IntoIterator<Item = (Span, String)>,
         applicability: Applicability,
     ) -> &mut Self {
         self.multipart_suggestion_with_style(
@@ -807,7 +807,7 @@ impl Diagnostic {
     pub fn multipart_suggestions(
         &mut self,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestions: impl IntoIterator<Item = Vec<(Span, String)>>,
+        suggestions: impl IntoIterator<Item = impl IntoIterator<Item = (Span, String)>>,
         applicability: Applicability,
     ) -> &mut Self {
         let substitutions = suggestions

compiler/rustc_errors/src/diagnostic_builder.rs

@@ -625,19 +625,19 @@ impl<'a, G: EmissionGuarantee> DiagnosticBuilder<'a, G> {
     forward!(pub fn multipart_suggestion(
         &mut self,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestion: Vec<(Span, String)>,
+        suggestion: impl IntoIterator<Item = (Span, String)>,
         applicability: Applicability,
     ) -> &mut Self);
     forward!(pub fn multipart_suggestion_verbose(
         &mut self,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestion: Vec<(Span, String)>,
+        suggestion: impl IntoIterator<Item = (Span, String)>,
         applicability: Applicability,
     ) -> &mut Self);
     forward!(pub fn tool_only_multipart_suggestion(
         &mut self,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestion: Vec<(Span, String)>,
+        suggestion: impl IntoIterator<Item = (Span, String)>,
         applicability: Applicability,
     ) -> &mut Self);
     forward!(pub fn span_suggestion(
@@ -657,7 +657,7 @@ impl<'a, G: EmissionGuarantee> DiagnosticBuilder<'a, G> {
     forward!(pub fn multipart_suggestions(
         &mut self,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestions: impl IntoIterator<Item = Vec<(Span, String)>>,
+        suggestions: impl IntoIterator<Item = impl IntoIterator<Item = (Span, String)>>,
         applicability: Applicability,
     ) -> &mut Self);
     forward!(pub fn span_suggestion_short(

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -844,7 +844,8 @@ fn check_object_unsafe_self_trait_by_name(tcx: TyCtxt<'_>, item: &hir::TraitItem
         if tcx.check_is_object_safe(trait_def_id) {
             return;
         }
-        let sugg = trait_should_be_self.iter().map(|span| (*span, "Self".to_string())).collect();
+        let sugg =
+            trait_should_be_self.iter().map(|span| (*span, "Self".to_string())).collect::<Vec<_>>();
         tcx.sess
             .struct_span_err(
                 trait_should_be_self,

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

@@ -270,10 +270,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 }) => {
                     diag.multipart_suggestion_verbose(
                         "consider `await`ing on the `Future`",
-                        prior_arms
-                            .iter()
-                            .map(|arm| (arm.shrink_to_hi(), ".await".to_string()))
-                            .collect(),
+                        prior_arms.iter().map(|arm| (arm.shrink_to_hi(), ".await".to_string())),
                         Applicability::MaybeIncorrect,
                     );
                 }

compiler/rustc_lint/src/context.rs

@@ -632,7 +632,7 @@ pub trait LintContext: Sized {
                     if !spans.is_empty() {
                         db.multipart_suggestion_with_style(
                             "if their presence wasn't intentional, you can remove them",
-                            spans.into_iter().map(|(_, span)| (span, "".to_string())).collect(),
+                            spans.into_iter().map(|(_, span)| (span, "".to_string())),
                             Applicability::MachineApplicable,
                             SuggestionStyle::HideCodeAlways,
                         );

compiler/rustc_lint/src/lints.rs

@@ -701,19 +701,16 @@ impl AddToDiagnostic for HiddenUnicodeCodepointsDiagSub {
             HiddenUnicodeCodepointsDiagSub::Escape { spans } => {
                 diag.multipart_suggestion_with_style(
                     fluent::suggestion_remove,
-                    spans.iter().map(|(_, span)| (*span, "".to_string())).collect(),
+                    spans.iter().map(|(_, span)| (*span, "".to_string())),
                     Applicability::MachineApplicable,
                     SuggestionStyle::HideCodeAlways,
                 );
                 diag.multipart_suggestion(
                     fluent::suggestion_escape,
-                    spans
-                        .into_iter()
-                        .map(|(c, span)| {
-                            let c = format!("{:?}", c);
-                            (span, c[1..c.len() - 1].to_string())
-                        })
-                        .collect(),
+                    spans.into_iter().map(|(c, span)| {
+                        let c = format!("{:?}", c);
+                        (span, c[1..c.len() - 1].to_string())
+                    }),
                     Applicability::MachineApplicable,
                 );
             }

compiler/rustc_middle/src/ty/diagnostics.rs

@@ -387,7 +387,7 @@ pub fn suggest_constraining_type_params<'a>(
     } else if suggestions.len() > 1 {
         err.multipart_suggestion_verbose(
             "consider restricting type parameters",
-            suggestions.into_iter().map(|(span, suggestion, _)| (span, suggestion)).collect(),
+            suggestions.into_iter().map(|(span, suggestion, _)| (span, suggestion)),
             applicability,
         );
     }

compiler/rustc_passes/src/liveness.rs

@@ -1605,18 +1605,15 @@ impl<'tcx> Liveness<'_, 'tcx> {
                     |lint| {
                         lint.multipart_suggestion(
                             "try removing the field",
-                            hir_ids_and_spans
-                                .iter()
-                                .map(|(_, pat_span, _)| {
-                                    let span = self
-                                        .ir
-                                        .tcx
-                                        .sess
-                                        .source_map()
-                                        .span_extend_to_next_char(*pat_span, ',', true);
-                                    (span.with_hi(BytePos(span.hi().0 + 1)), String::new())
-                                })
-                                .collect(),
+                            hir_ids_and_spans.iter().map(|(_, pat_span, _)| {
+                                let span = self
+                                    .ir
+                                    .tcx
+                                    .sess
+                                    .source_map()
+                                    .span_extend_to_next_char(*pat_span, ',', true);
+                                (span.with_hi(BytePos(span.hi().0 + 1)), String::new())
+                            }),
                             Applicability::MachineApplicable,
                         )
                     },

compiler/rustc_resolve/src/diagnostics.rs

@@ -1612,7 +1612,7 @@ impl<'a> Resolver<'a> {
                         "consider making the field{} publicly accessible",
                         pluralize!(fields.len())
                     ),
-                    fields.iter().map(|span| (*span, "pub ".to_string())).collect(),
+                    fields.iter().map(|span| (*span, "pub ".to_string())),
                     Applicability::MaybeIncorrect,
                 );
             }

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -1464,7 +1464,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                                     "consider making the field{} publicly accessible",
                                     pluralize!(fields.len())
                                 ),
-                                fields.iter().map(|span| (*span, "pub ".to_string())).collect(),
+                                fields.iter().map(|span| (*span, "pub ".to_string())),
                                 Applicability::MaybeIncorrect,
                             );
                         }
@@ -2580,9 +2580,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                     |err, higher_ranked, span, message, intro_sugg| {
                         err.multipart_suggestion_verbose(
                             message,
-                            std::iter::once((span, intro_sugg))
-                                .chain(spans_suggs.iter().cloned())
-                                .collect(),
+                            std::iter::once((span, intro_sugg)).chain(spans_suggs.iter().cloned()),
                             Applicability::MaybeIncorrect,
                         );
                         higher_ranked

src/tools/clippy/clippy_lints/src/index_refutable_slice.rs

@@ -164,8 +164,7 @@ fn lint_slice(cx: &LateContext<'_>, slice: &SliceLintInformation) {
                     slice
                         .pattern_spans
                         .iter()
-                        .map(|span| (*span, pat_sugg.clone()))
-                        .collect(),
+                        .map(|span| (*span, pat_sugg.clone())),
                     Applicability::MaybeIncorrect,
                 );
 
@@ -174,8 +173,7 @@ fn lint_slice(cx: &LateContext<'_>, slice: &SliceLintInformation) {
                     slice
                         .index_use
                         .iter()
-                        .map(|(index, span)| (*span, value_name(*index)))
-                        .collect(),
+                        .map(|(index, span)| (*span, value_name(*index))),
                     Applicability::MaybeIncorrect,
                 );
 

src/tools/clippy/clippy_lints/src/needless_for_each.rs

@@ -92,8 +92,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessForEach {
                             ret_collector
                                 .spans
                                 .into_iter()
-                                .map(|span| (span, "continue".to_string()))
-                                .collect(),
+                                .map(|span| (span, "continue".to_string())),
                         ),
                     )
                 };

src/tools/clippy/clippy_lints/src/ptr.rs

@@ -233,8 +233,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
                                 r.expr_span,
                                 format!("{}{}", snippet_opt(cx, r.self_span).unwrap(), r.replacement),
                             )
-                        }))
-                        .collect(),
+                        })),
                     Applicability::Unspecified,
                 );
             });

src/tools/clippy/clippy_utils/src/diagnostics.rs

@@ -232,5 +232,5 @@ pub fn multispan_sugg_with_applicability<I>(
 ) where
     I: IntoIterator<Item = (Span, String)>,
 {
-    diag.multipart_suggestion(help_msg, sugg.into_iter().collect(), applicability);
+    diag.multipart_suggestion(help_msg, sugg, applicability);
 }