Remove needless lifetimes

src/librustc/lint/mod.rs

@@ -765,7 +765,7 @@ pub fn maybe_lint_level_root(tcx: TyCtxt<'_>, id: hir::HirId) -> bool {
     attrs.iter().any(|attr| Level::from_symbol(attr.name_or_empty()).is_some())
 }
 
-fn lint_levels<'tcx>(tcx: TyCtxt<'tcx>, cnum: CrateNum) -> &'tcx LintLevelMap {
+fn lint_levels(tcx: TyCtxt<'_>, cnum: CrateNum) -> &LintLevelMap {
     assert_eq!(cnum, LOCAL_CRATE);
     let mut builder = LintLevelMapBuilder {
         levels: LintLevelSets::builder(tcx.sess),

src/librustc/middle/cstore.rs

@@ -211,7 +211,7 @@ pub trait CrateStore {
     fn crates_untracked(&self) -> Vec<CrateNum>;
 
     // utility functions
-    fn encode_metadata<'tcx>(&self, tcx: TyCtxt<'tcx>) -> EncodedMetadata;
+    fn encode_metadata(&self, tcx: TyCtxt<'_>) -> EncodedMetadata;
     fn metadata_encoding_version(&self) -> &[u8];
 }
 

src/librustc/middle/dead.rs

@@ -26,7 +26,7 @@ use syntax_pos;
 // explored. For example, if it's a live Node::Item that is a
 // function, then we should explore its block to check for codes that
 // may need to be marked as live.
-fn should_explore<'tcx>(tcx: TyCtxt<'tcx>, hir_id: hir::HirId) -> bool {
+fn should_explore(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool {
     match tcx.hir().find(hir_id) {
         Some(Node::Item(..)) |
         Some(Node::ImplItem(..)) |
@@ -662,7 +662,7 @@ impl Visitor<'tcx> for DeadVisitor<'tcx> {
     }
 }
 
-pub fn check_crate<'tcx>(tcx: TyCtxt<'tcx>) {
+pub fn check_crate(tcx: TyCtxt<'_>) {
     let access_levels = &tcx.privacy_access_levels(LOCAL_CRATE);
     let krate = tcx.hir().krate();
     let live_symbols = find_live(tcx, access_levels, krate);

src/librustc/middle/dependency_format.rs

@@ -81,7 +81,7 @@ pub enum Linkage {
     Dynamic,
 }
 
-pub fn calculate<'tcx>(tcx: TyCtxt<'tcx>) {
+pub fn calculate(tcx: TyCtxt<'_>) {
     let sess = &tcx.sess;
     let fmts = sess.crate_types.borrow().iter().map(|&ty| {
         let linkage = calculate_type(tcx, ty);
@@ -92,7 +92,7 @@ pub fn calculate<'tcx>(tcx: TyCtxt<'tcx>) {
     sess.dependency_formats.set(fmts);
 }
 
-fn calculate_type<'tcx>(tcx: TyCtxt<'tcx>, ty: config::CrateType) -> DependencyList {
+fn calculate_type(tcx: TyCtxt<'_>, ty: config::CrateType) -> DependencyList {
     let sess = &tcx.sess;
 
     if !sess.opts.output_types.should_codegen() {
@@ -267,7 +267,7 @@ fn add_library(
     }
 }
 
-fn attempt_static<'tcx>(tcx: TyCtxt<'tcx>) -> Option<DependencyList> {
+fn attempt_static(tcx: TyCtxt<'_>) -> Option<DependencyList> {
     let sess = &tcx.sess;
     let crates = cstore::used_crates(tcx, RequireStatic);
     if !crates.iter().by_ref().all(|&(_, ref p)| p.is_some()) {
@@ -324,7 +324,7 @@ fn activate_injected_dep(injected: Option<CrateNum>,
 
 // After the linkage for a crate has been determined we need to verify that
 // there's only going to be one allocator in the output.
-fn verify_ok<'tcx>(tcx: TyCtxt<'tcx>, list: &[Linkage]) {
+fn verify_ok(tcx: TyCtxt<'_>, list: &[Linkage]) {
     let sess = &tcx.sess;
     if list.len() == 0 {
         return

src/librustc/middle/intrinsicck.rs

@@ -10,7 +10,7 @@ use syntax_pos::{Span, sym};
 use crate::hir::intravisit::{self, Visitor, NestedVisitorMap};
 use crate::hir;
 
-fn check_mod_intrinsics<'tcx>(tcx: TyCtxt<'tcx>, module_def_id: DefId) {
+fn check_mod_intrinsics(tcx: TyCtxt<'_>, module_def_id: DefId) {
     tcx.hir().visit_item_likes_in_module(
         module_def_id,
         &mut ItemVisitor { tcx }.as_deep_visitor()

src/librustc/middle/lib_features.rs

@@ -142,7 +142,7 @@ impl Visitor<'tcx> for LibFeatureCollector<'tcx> {
     }
 }
 
-pub fn collect<'tcx>(tcx: TyCtxt<'tcx>) -> LibFeatures {
+pub fn collect(tcx: TyCtxt<'_>) -> LibFeatures {
     let mut collector = LibFeatureCollector::new(tcx);
     intravisit::walk_crate(&mut collector, tcx.hir().krate());
     collector.lib_features

src/librustc/middle/liveness.rs

@@ -181,7 +181,7 @@ impl<'tcx> Visitor<'tcx> for IrMaps<'tcx> {
     fn visit_arm(&mut self, a: &'tcx hir::Arm) { visit_arm(self, a); }
 }
 
-fn check_mod_liveness<'tcx>(tcx: TyCtxt<'tcx>, module_def_id: DefId) {
+fn check_mod_liveness(tcx: TyCtxt<'_>, module_def_id: DefId) {
     tcx.hir().visit_item_likes_in_module(
         module_def_id,
         &mut IrMaps::new(tcx, module_def_id).as_deep_visitor(),

src/librustc/middle/reachable.rs

@@ -42,8 +42,8 @@ fn item_might_be_inlined(tcx: TyCtxt<'tcx>, item: &hir::Item, attrs: CodegenFnAt
     }
 }
 
-fn method_might_be_inlined<'tcx>(
+fn method_might_be_inlined(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     impl_item: &hir::ImplItem,
     impl_src: DefId,
 ) -> bool {
@@ -391,7 +391,7 @@ impl<'a, 'tcx> ItemLikeVisitor<'tcx> for CollectPrivateImplItemsVisitor<'a, 'tcx
 #[derive(Clone, HashStable)]
 pub struct ReachableSet(pub Lrc<HirIdSet>);
 
-fn reachable_set<'tcx>(tcx: TyCtxt<'tcx>, crate_num: CrateNum) -> ReachableSet {
+fn reachable_set(tcx: TyCtxt<'_>, crate_num: CrateNum) -> ReachableSet {
     debug_assert!(crate_num == LOCAL_CRATE);
 
     let access_levels = &tcx.privacy_access_levels(LOCAL_CRATE);

src/librustc/middle/region.rs

@@ -1446,7 +1446,7 @@ impl<'tcx> Visitor<'tcx> for RegionResolutionVisitor<'tcx> {
     }
 }
 
-fn region_scope_tree<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ScopeTree {
+fn region_scope_tree(tcx: TyCtxt<'_>, def_id: DefId) -> &ScopeTree {
     let closure_base_def_id = tcx.closure_base_def_id(def_id);
     if closure_base_def_id != def_id {
         return tcx.region_scope_tree(closure_base_def_id);

src/librustc/middle/resolve_lifetime.rs

@@ -368,7 +368,7 @@ pub fn provide(providers: &mut ty::query::Providers<'_>) {
 /// entire crate. You should not read the result of this query
 /// directly, but rather use `named_region_map`, `is_late_bound_map`,
 /// etc.
-fn resolve_lifetimes<'tcx>(tcx: TyCtxt<'tcx>, for_krate: CrateNum) -> &'tcx ResolveLifetimes {
+fn resolve_lifetimes(tcx: TyCtxt<'_>, for_krate: CrateNum) -> &ResolveLifetimes {
     assert_eq!(for_krate, LOCAL_CRATE);
 
     let named_region_map = krate(tcx);
@@ -395,7 +395,7 @@ fn resolve_lifetimes<'tcx>(tcx: TyCtxt<'tcx>, for_krate: CrateNum) -> &'tcx Reso
     tcx.arena.alloc(rl)
 }
 
-fn krate<'tcx>(tcx: TyCtxt<'tcx>) -> NamedRegionMap {
+fn krate(tcx: TyCtxt<'_>) -> NamedRegionMap {
     let krate = tcx.hir().krate();
     let mut map = NamedRegionMap {
         defs: Default::default(),

src/librustc/middle/stability.rs

@@ -466,7 +466,7 @@ impl<'tcx> Index<'tcx> {
 
 /// Cross-references the feature names of unstable APIs with enabled
 /// features and possibly prints errors.
-fn check_mod_unstable_api_usage<'tcx>(tcx: TyCtxt<'tcx>, module_def_id: DefId) {
+fn check_mod_unstable_api_usage(tcx: TyCtxt<'_>, module_def_id: DefId) {
     tcx.hir().visit_item_likes_in_module(module_def_id, &mut Checker { tcx }.as_deep_visitor());
 }
 
@@ -836,7 +836,7 @@ impl<'tcx> TyCtxt<'tcx> {
 /// Given the list of enabled features that were not language features (i.e., that
 /// were expected to be library features), and the list of features used from
 /// libraries, identify activated features that don't exist and error about them.
-pub fn check_unused_or_stable_features<'tcx>(tcx: TyCtxt<'tcx>) {
+pub fn check_unused_or_stable_features(tcx: TyCtxt<'_>) {
     let access_levels = &tcx.privacy_access_levels(LOCAL_CRATE);
 
     if tcx.stability().staged_api[&LOCAL_CRATE] {
@@ -920,8 +920,8 @@ pub fn check_unused_or_stable_features<'tcx>(tcx: TyCtxt<'tcx>) {
     // don't lint about unused features. We should reenable this one day!
 }
 
-fn unnecessary_stable_feature_lint<'tcx>(
+fn unnecessary_stable_feature_lint(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     span: Span,
     feature: Symbol,
     since: Symbol,

src/librustc/mir/mod.rs

@@ -2867,19 +2867,19 @@ impl<'tcx> graph::WithStartNode for Body<'tcx> {
 }
 
 impl<'tcx> graph::WithPredecessors for Body<'tcx> {
-    fn predecessors<'graph>(
+    fn predecessors(
-        &'graph self,
+        &self,
         node: Self::Node,
-    ) -> <Self as GraphPredecessors<'graph>>::Iter {
+    ) -> <Self as GraphPredecessors<'_>>::Iter {
         self.predecessors_for(node).clone().into_iter()
     }
 }
 
 impl<'tcx> graph::WithSuccessors for Body<'tcx> {
-    fn successors<'graph>(
+    fn successors(
-        &'graph self,
+        &self,
         node: Self::Node,
-    ) -> <Self as GraphSuccessors<'graph>>::Iter {
+    ) -> <Self as GraphSuccessors<'_>>::Iter {
         self.basic_blocks[node].terminator().successors().cloned()
     }
 }

src/librustc/session/config.rs

@@ -269,11 +269,11 @@ impl OutputTypes {
         self.0.contains_key(key)
     }
 
-    pub fn keys<'a>(&'a self) -> BTreeMapKeysIter<'a, OutputType, Option<PathBuf>> {
+    pub fn keys(&self) -> BTreeMapKeysIter<'_, OutputType, Option<PathBuf>> {
         self.0.keys()
     }
 
-    pub fn values<'a>(&'a self) -> BTreeMapValuesIter<'a, OutputType, Option<PathBuf>> {
+    pub fn values(&self) -> BTreeMapValuesIter<'_, OutputType, Option<PathBuf>> {
         self.0.values()
     }
 
@@ -316,7 +316,7 @@ impl Externs {
         self.0.get(key)
     }
 
-    pub fn iter<'a>(&'a self) -> BTreeMapIter<'a, String, ExternEntry> {
+    pub fn iter(&self) -> BTreeMapIter<'_, String, ExternEntry> {
         self.0.iter()
     }
 }

src/librustc/session/mod.rs

@@ -215,66 +215,66 @@ impl Session {
         *self.crate_disambiguator.get()
     }
 
-    pub fn struct_span_warn<'a, S: Into<MultiSpan>>(
+    pub fn struct_span_warn<S: Into<MultiSpan>>(
-        &'a self,
+        &self,
         sp: S,
         msg: &str,
-    ) -> DiagnosticBuilder<'a> {
+    ) -> DiagnosticBuilder<'_> {
         self.diagnostic().struct_span_warn(sp, msg)
     }
-    pub fn struct_span_warn_with_code<'a, S: Into<MultiSpan>>(
+    pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
-        &'a self,
+        &self,
         sp: S,
         msg: &str,
         code: DiagnosticId,
-    ) -> DiagnosticBuilder<'a> {
+    ) -> DiagnosticBuilder<'_> {
         self.diagnostic().struct_span_warn_with_code(sp, msg, code)
     }
-    pub fn struct_warn<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
+    pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
         self.diagnostic().struct_warn(msg)
     }
-    pub fn struct_span_err<'a, S: Into<MultiSpan>>(
+    pub fn struct_span_err<S: Into<MultiSpan>>(
-        &'a self,
+        &self,
         sp: S,
         msg: &str,
-    ) -> DiagnosticBuilder<'a> {
+    ) -> DiagnosticBuilder<'_> {
         self.diagnostic().struct_span_err(sp, msg)
     }
-    pub fn struct_span_err_with_code<'a, S: Into<MultiSpan>>(
+    pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
-        &'a self,
+        &self,
         sp: S,
         msg: &str,
         code: DiagnosticId,
-    ) -> DiagnosticBuilder<'a> {
+    ) -> DiagnosticBuilder<'_> {
         self.diagnostic().struct_span_err_with_code(sp, msg, code)
     }
     // FIXME: This method should be removed (every error should have an associated error code).
-    pub fn struct_err<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
+    pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
         self.diagnostic().struct_err(msg)
     }
-    pub fn struct_err_with_code<'a>(
+    pub fn struct_err_with_code(
-        &'a self,
+        &self,
         msg: &str,
         code: DiagnosticId,
-    ) -> DiagnosticBuilder<'a> {
+    ) -> DiagnosticBuilder<'_> {
         self.diagnostic().struct_err_with_code(msg, code)
     }
-    pub fn struct_span_fatal<'a, S: Into<MultiSpan>>(
+    pub fn struct_span_fatal<S: Into<MultiSpan>>(
-        &'a self,
+        &self,
         sp: S,
         msg: &str,
-    ) -> DiagnosticBuilder<'a> {
+    ) -> DiagnosticBuilder<'_> {
         self.diagnostic().struct_span_fatal(sp, msg)
     }
-    pub fn struct_span_fatal_with_code<'a, S: Into<MultiSpan>>(
+    pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
-        &'a self,
+        &self,
         sp: S,
         msg: &str,
         code: DiagnosticId,
-    ) -> DiagnosticBuilder<'a> {
+    ) -> DiagnosticBuilder<'_> {
         self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
     }
-    pub fn struct_fatal<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
+    pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
         self.diagnostic().struct_fatal(msg)
     }
 
@@ -416,7 +416,7 @@ impl Session {
     pub fn next_node_id(&self) -> NodeId {
         self.reserve_node_ids(1)
     }
-    pub fn diagnostic<'a>(&'a self) -> &'a errors::Handler {
+    pub fn diagnostic(&self) -> &errors::Handler {
         &self.parse_sess.span_diagnostic
     }
 
@@ -504,7 +504,7 @@ impl Session {
         );
     }
 
-    pub fn source_map<'a>(&'a self) -> &'a source_map::SourceMap {
+    pub fn source_map(&self) -> &source_map::SourceMap {
         self.parse_sess.source_map()
     }
     pub fn verbose(&self) -> bool {

src/librustc/traits/specialize/mod.rs

@@ -145,8 +145,8 @@ pub fn find_associated_item<'tcx>(
 /// Specialization is determined by the sets of types to which the impls apply;
 /// `impl1` specializes `impl2` if it applies to a subset of the types `impl2` applies
 /// to.
-pub(super) fn specializes<'tcx>(
+pub(super) fn specializes(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     (impl1_def_id, impl2_def_id): (DefId, DefId),
 ) -> bool {
     debug!("specializes({:?}, {:?})", impl1_def_id, impl2_def_id);
@@ -282,10 +282,10 @@ fn fulfill_implication<'a, 'tcx>(
 }
 
 // Query provider for `specialization_graph_of`.
-pub(super) fn specialization_graph_provider<'tcx>(
+pub(super) fn specialization_graph_provider(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     trait_id: DefId,
-) -> &'tcx specialization_graph::Graph {
+) -> &specialization_graph::Graph {
     let mut sg = specialization_graph::Graph::new();
 
     let mut trait_impls = tcx.all_impls(trait_id);

src/librustc/ty/query/on_disk_cache.rs

@@ -306,9 +306,9 @@ impl<'sess> OnDiskCache<'sess> {
     }
 
     /// Loads a diagnostic emitted during the previous compilation session.
-    pub fn load_diagnostics<'tcx>(
+    pub fn load_diagnostics(
         &self,
-        tcx: TyCtxt<'tcx>,
+        tcx: TyCtxt<'_>,
         dep_node_index: SerializedDepNodeIndex,
     ) -> Vec<Diagnostic> {
         let diagnostics: Option<EncodedDiagnostics> = self.load_indexed(
@@ -335,9 +335,9 @@ impl<'sess> OnDiskCache<'sess> {
 
     /// Returns the cached query result if there is something in the cache for
     /// the given `SerializedDepNodeIndex`; otherwise returns `None`.
-    pub fn try_load_query_result<'tcx, T>(
+    pub fn try_load_query_result<T>(
         &self,
-        tcx: TyCtxt<'tcx>,
+        tcx: TyCtxt<'_>,
         dep_node_index: SerializedDepNodeIndex,
     ) -> Option<T>
     where

src/librustc/ty/query/plumbing.rs

@@ -1166,7 +1166,7 @@ macro_rules! define_provider_struct {
 /// then `force_from_dep_node()` should not fail for it. Otherwise, you can just
 /// add it to the "We don't have enough information to reconstruct..." group in
 /// the match below.
-pub fn force_from_dep_node<'tcx>(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> bool {
+pub fn force_from_dep_node(tcx: TyCtxt<'_>, dep_node: &DepNode) -> bool {
     use crate::dep_graph::RecoverKey;
 
     // We must avoid ever having to call force_from_dep_node() for a

src/librustc_codegen_ssa/mir/analyze.rs

@@ -273,7 +273,7 @@ impl CleanupKind {
     }
 }
 
-pub fn cleanup_kinds<'tcx>(mir: &mir::Body<'tcx>) -> IndexVec<mir::BasicBlock, CleanupKind> {
+pub fn cleanup_kinds(mir: &mir::Body<'_>) -> IndexVec<mir::BasicBlock, CleanupKind> {
     fn discover_masters<'tcx>(result: &mut IndexVec<mir::BasicBlock, CleanupKind>,
                               mir: &mir::Body<'tcx>) {
         for (bb, data) in mir.basic_blocks().iter_enumerated() {

src/librustc_incremental/persist/dirty_clean.rs

@@ -206,7 +206,7 @@ impl Assertion {
     }
 }
 
-pub fn check_dirty_clean_annotations<'tcx>(tcx: TyCtxt<'tcx>) {
+pub fn check_dirty_clean_annotations(tcx: TyCtxt<'_>) {
     // can't add `#[rustc_dirty]` etc without opting in to this feature
     if !tcx.features().rustc_attrs {
         return;

src/librustc_incremental/persist/load.rs

@@ -15,7 +15,7 @@ use super::fs::*;
 use super::file_format;
 use super::work_product;
 
-pub fn dep_graph_tcx_init<'tcx>(tcx: TyCtxt<'tcx>) {
+pub fn dep_graph_tcx_init(tcx: TyCtxt<'_>) {
     if !tcx.dep_graph.is_fully_enabled() {
         return
     }
@@ -192,7 +192,7 @@ pub fn load_dep_graph(sess: &Session) -> DepGraphFuture {
     }))
 }
 
-pub fn load_query_result_cache<'sess>(sess: &'sess Session) -> OnDiskCache<'sess> {
+pub fn load_query_result_cache(sess: &Session) -> OnDiskCache<'_> {
     if sess.opts.incremental.is_none() ||
        !sess.opts.debugging_opts.incremental_queries {
         return OnDiskCache::new_empty(sess.source_map());

src/librustc_incremental/persist/save.rs

@@ -15,7 +15,7 @@ use super::dirty_clean;
 use super::file_format;
 use super::work_product;
 
-pub fn save_dep_graph<'tcx>(tcx: TyCtxt<'tcx>) {
+pub fn save_dep_graph(tcx: TyCtxt<'_>) {
     debug!("save_dep_graph()");
     tcx.dep_graph.with_ignore(|| {
         let sess = tcx.sess;

src/librustc_mir/borrow_check/nll/region_infer/values.rs

@@ -162,7 +162,7 @@ impl<N: Idx> LivenessValues<N> {
     }
 
     /// Iterate through each region that has a value in this set.
-    crate fn rows<'a>(&'a self) -> impl Iterator<Item = N> {
+    crate fn rows(&self) -> impl Iterator<Item=N> {
         self.points.rows()
     }
 

src/librustc_mir/build/matches/test.rs

@@ -826,6 +826,6 @@ impl Test<'_> {
     }
 }
 
-fn is_switch_ty<'tcx>(ty: Ty<'tcx>) -> bool {
+fn is_switch_ty(ty: Ty<'_>) -> bool {
     ty.is_integral() || ty.is_char() || ty.is_bool()
 }

src/librustc_mir/hair/pattern/_match.rs

@@ -835,7 +835,7 @@ impl<'tcx> IntRange<'tcx> {
     fn from_ctor(tcx: TyCtxt<'tcx>, ctor: &Constructor<'tcx>) -> Option<IntRange<'tcx>> {
         // Floating-point ranges are permitted and we don't want
         // to consider them when constructing integer ranges.
-        fn is_integral<'tcx>(ty: Ty<'tcx>) -> bool {
+        fn is_integral(ty: Ty<'_>) -> bool {
             match ty.sty {
                 ty::Char | ty::Int(_) | ty::Uint(_) => true,
                 _ => false,

src/librustc_mir/hair/pattern/check_match.rs

@@ -26,7 +26,7 @@ use std::slice;
 use syntax::ptr::P;
 use syntax_pos::{Span, DUMMY_SP, MultiSpan};
 
-pub(crate) fn check_match<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) {
+pub(crate) fn check_match(tcx: TyCtxt<'_>, def_id: DefId) {
     let body_id = if let Some(id) = tcx.hir().as_local_hir_id(def_id) {
         tcx.hir().body_owned_by(id)
     } else {
@@ -43,7 +43,7 @@ pub(crate) fn check_match<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) {
     }.visit_body(tcx.hir().body(body_id));
 }
 
-fn create_e0004<'a>(sess: &'a Session, sp: Span, error_message: String) -> DiagnosticBuilder<'a> {
+fn create_e0004(sess: &Session, sp: Span, error_message: String) -> DiagnosticBuilder<'_> {
     struct_span_err!(sess, sp, E0004, "{}", &error_message)
 }
 

src/librustc_mir/monomorphize/collector.rs

@@ -281,10 +281,10 @@ impl<'tcx> InliningMap<'tcx> {
     }
 }
 
-pub fn collect_crate_mono_items<'tcx>(
+pub fn collect_crate_mono_items(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     mode: MonoItemCollectionMode,
-) -> (FxHashSet<MonoItem<'tcx>>, InliningMap<'tcx>) {
+) -> (FxHashSet<MonoItem<'_>>, InliningMap<'_>) {
     let roots = time(tcx.sess, "collecting roots", || {
         collect_roots(tcx, mode)
     });
@@ -315,7 +315,7 @@ pub fn collect_crate_mono_items<'tcx>(
 
 // Find all non-generic items by walking the HIR. These items serve as roots to
 // start monomorphizing from.
-fn collect_roots<'tcx>(tcx: TyCtxt<'tcx>, mode: MonoItemCollectionMode) -> Vec<MonoItem<'tcx>> {
+fn collect_roots(tcx: TyCtxt<'_>, mode: MonoItemCollectionMode) -> Vec<MonoItem<'_>> {
     debug!("Collecting roots");
     let mut roots = Vec::new();
 
@@ -912,7 +912,7 @@ fn find_vtable_types_for_unsizing<'tcx>(
     }
 }
 
-fn create_fn_mono_item<'tcx>(instance: Instance<'tcx>) -> MonoItem<'tcx> {
+fn create_fn_mono_item(instance: Instance<'_>) -> MonoItem<'_> {
     debug!("create_fn_mono_item(instance={})", instance);
     MonoItem::Fn(instance)
 }
@@ -1114,7 +1114,7 @@ impl RootCollector<'_, 'v> {
     }
 }
 
-fn item_requires_monomorphization<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool {
+fn item_requires_monomorphization(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
     let generics = tcx.generics_of(def_id);
     generics.requires_monomorphization(tcx)
 }
@@ -1243,7 +1243,7 @@ fn collect_neighbours<'tcx>(
     }
 }
 
-fn def_id_to_string<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> String {
+fn def_id_to_string(tcx: TyCtxt<'_>, def_id: DefId) -> String {
     let mut output = String::new();
     let printer = DefPathBasedNames::new(tcx, false, false);
     printer.push_def_path(def_id, &mut output);

src/librustc_mir/monomorphize/partitioning.rs

@@ -839,10 +839,10 @@ where
     }
 }
 
-fn collect_and_partition_mono_items<'tcx>(
+fn collect_and_partition_mono_items(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     cnum: CrateNum,
-) -> (Arc<DefIdSet>, Arc<Vec<Arc<CodegenUnit<'tcx>>>>) {
+) -> (Arc<DefIdSet>, Arc<Vec<Arc<CodegenUnit<'_>>>>) {
     assert_eq!(cnum, LOCAL_CRATE);
 
     let collection_mode = match tcx.sess.opts.debugging_opts.print_mono_items {

src/librustc_mir/util/graphviz.rs

@@ -8,8 +8,8 @@ use std::io::{self, Write};
 use super::pretty::dump_mir_def_ids;
 
 /// Write a graphviz DOT graph of a list of MIRs.
-pub fn write_mir_graphviz<'tcx, W>(
+pub fn write_mir_graphviz<W>(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     single: Option<DefId>,
     w: &mut W,
 ) -> io::Result<()>

src/librustc_mir/util/liveness.rs

@@ -56,8 +56,8 @@ pub struct LivenessResult {
 
 /// Computes which local variables are live within the given function
 /// `mir`, including drops.
-pub fn liveness_of_locals<'tcx>(
+pub fn liveness_of_locals(
-    body: &Body<'tcx>,
+    body: &Body<'_>,
 ) -> LivenessResult {
     let num_live_vars = body.local_decls.len();
 
@@ -243,8 +243,8 @@ impl<'tcx> Visitor<'tcx> for DefsUsesVisitor
     }
 }
 
-fn block<'tcx>(
+fn block(
-    b: &BasicBlockData<'tcx>,
+    b: &BasicBlockData<'_>,
     locals: usize,
 ) -> DefsUses {
     let mut visitor = DefsUsesVisitor {

src/librustc_mir/util/mod.rs

@@ -21,7 +21,7 @@ pub use self::graphviz::{graphviz_safe_def_name, write_mir_graphviz};
 pub use self::graphviz::write_node_label as write_graphviz_node_label;
 
 /// If possible, suggest replacing `ref` with `ref mut`.
-pub fn suggest_ref_mut<'tcx>(tcx: TyCtxt<'tcx>, binding_span: Span) -> Option<(String)> {
+pub fn suggest_ref_mut(tcx: TyCtxt<'_>, binding_span: Span) -> Option<(String)> {
     let hi_src = tcx.sess.source_map().span_to_snippet(binding_span).unwrap();
     if hi_src.starts_with("ref")
         && hi_src["ref".len()..].starts_with(Pattern_White_Space)

src/librustc_resolve/lib.rs

@@ -198,9 +198,9 @@ enum ResolutionError<'a> {
 ///
 /// This takes the error provided, combines it with the span and any additional spans inside the
 /// error and emits it.
-fn resolve_error<'sess, 'a>(resolver: &'sess Resolver<'_>,
+fn resolve_error(resolver: &Resolver<'_>,
-                            span: Span,
+                 span: Span,
-                            resolution_error: ResolutionError<'a>) {
+                 resolution_error: ResolutionError<'_>) {
     resolve_struct_error(resolver, span, resolution_error).emit();
 }
 

src/librustc_traits/chalk_context/program_clauses/primitive.rs

@@ -15,7 +15,7 @@ use crate::lowering::Lower;
 use crate::generic_types;
 use std::iter;
 
-crate fn wf_clause_for_raw_ptr<'tcx>(tcx: TyCtxt<'tcx>, mutbl: hir::Mutability) -> Clauses<'tcx> {
+crate fn wf_clause_for_raw_ptr(tcx: TyCtxt<'_>, mutbl: hir::Mutability) -> Clauses<'_> {
     let ptr_ty = generic_types::raw_ptr(tcx, mutbl);
 
     let wf_clause = ProgramClause {
@@ -29,13 +29,13 @@ crate fn wf_clause_for_raw_ptr<'tcx>(tcx: TyCtxt<'tcx>, mutbl: hir::Mutability)
     tcx.mk_clauses(iter::once(wf_clause))
 }
 
-crate fn wf_clause_for_fn_ptr<'tcx>(
+crate fn wf_clause_for_fn_ptr(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     arity_and_output: usize,
     variadic: bool,
     unsafety: hir::Unsafety,
     abi: abi::Abi,
-) -> Clauses<'tcx> {
+) -> Clauses<'_> {
     let fn_ptr = generic_types::fn_ptr(tcx, arity_and_output, variadic, unsafety, abi);
 
     let wf_clause = ProgramClause {
@@ -50,7 +50,7 @@ crate fn wf_clause_for_fn_ptr<'tcx>(
     tcx.mk_clauses(iter::once(wf_clause))
 }
 
-crate fn wf_clause_for_slice<'tcx>(tcx: TyCtxt<'tcx>) -> Clauses<'tcx> {
+crate fn wf_clause_for_slice(tcx: TyCtxt<'_>) -> Clauses<'_> {
     let ty = generic_types::bound(tcx, 0);
     let slice_ty = tcx.mk_slice(ty);
 
@@ -111,7 +111,7 @@ crate fn wf_clause_for_array<'tcx>(
     tcx.mk_clauses(iter::once(wf_clause))
 }
 
-crate fn wf_clause_for_tuple<'tcx>(tcx: TyCtxt<'tcx>, arity: usize) -> Clauses<'tcx> {
+crate fn wf_clause_for_tuple(tcx: TyCtxt<'_>, arity: usize) -> Clauses<'_> {
     let type_list = generic_types::type_list(tcx, arity);
     let tuple_ty = tcx.mk_ty(ty::Tuple(type_list));
 
@@ -152,7 +152,7 @@ crate fn wf_clause_for_tuple<'tcx>(tcx: TyCtxt<'tcx>, arity: usize) -> Clauses<'
     tcx.mk_clauses(iter::once(wf_clause))
 }
 
-crate fn wf_clause_for_ref<'tcx>(tcx: TyCtxt<'tcx>, mutbl: hir::Mutability) -> Clauses<'tcx> {
+crate fn wf_clause_for_ref(tcx: TyCtxt<'_>, mutbl: hir::Mutability) -> Clauses<'_> {
     let region = tcx.mk_region(
         ty::ReLateBound(ty::INNERMOST, ty::BoundRegion::BrAnon(0))
     );
@@ -176,7 +176,7 @@ crate fn wf_clause_for_ref<'tcx>(tcx: TyCtxt<'tcx>, mutbl: hir::Mutability) -> C
     tcx.mk_clauses(iter::once(wf_clause))
 }
 
-crate fn wf_clause_for_fn_def<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Clauses<'tcx> {
+crate fn wf_clause_for_fn_def(tcx: TyCtxt<'_>, def_id: DefId) -> Clauses<'_> {
     let fn_def = generic_types::fn_def(tcx, def_id);
 
     let wf_clause = ProgramClause {

src/librustc_traits/dropck_outlives.rs

@@ -279,10 +279,10 @@ fn dtorck_constraint_for_ty<'tcx>(
 }
 
 /// Calculates the dtorck constraint for a type.
-crate fn adt_dtorck_constraint<'tcx>(
+crate fn adt_dtorck_constraint(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     def_id: DefId,
-) -> Result<DtorckConstraint<'tcx>, NoSolution> {
+) -> Result<DtorckConstraint<'_>, NoSolution> {
     let def = tcx.adt_def(def_id);
     let span = tcx.def_span(def_id);
     debug!("dtorck_constraint: {:?}", def);
@@ -313,7 +313,7 @@ crate fn adt_dtorck_constraint<'tcx>(
     Ok(result)
 }
 
-fn dedup_dtorck_constraint<'tcx>(c: &mut DtorckConstraint<'tcx>) {
+fn dedup_dtorck_constraint(c: &mut DtorckConstraint<'_>) {
     let mut outlives = FxHashSet::default();
     let mut dtorck_types = FxHashSet::default();
 

src/librustc_traits/lowering/environment.rs

@@ -160,7 +160,7 @@ crate fn program_clauses_for_env<'tcx>(
     );
 }
 
-crate fn environment<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Environment<'tcx> {
+crate fn environment(tcx: TyCtxt<'_>, def_id: DefId) -> Environment<'_> {
     use super::{Lower, IntoFromEnvGoal};
     use rustc::hir::{Node, TraitItemKind, ImplItemKind, ItemKind, ForeignItemKind};
 

src/librustc_traits/lowering/mod.rs

@@ -155,7 +155,7 @@ impl<'tcx> IntoWellFormedGoal for DomainGoal<'tcx> {
     }
 }
 
-crate fn program_clauses_for<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Clauses<'tcx> {
+crate fn program_clauses_for(tcx: TyCtxt<'_>, def_id: DefId) -> Clauses<'_> {
     // FIXME(eddyb) this should only be using `def_kind`.
     match tcx.def_key(def_id).disambiguated_data.data {
         DefPathData::TypeNs(..) => match tcx.def_kind(def_id) {
@@ -181,7 +181,7 @@ crate fn program_clauses_for<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Clauses<
     }
 }
 
-fn program_clauses_for_trait<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Clauses<'tcx> {
+fn program_clauses_for_trait(tcx: TyCtxt<'_>, def_id: DefId) -> Clauses<'_> {
     // `trait Trait<P1..Pn> where WC { .. } // P0 == Self`
 
     // Rule Implemented-From-Env (see rustc guide)
@@ -337,7 +337,7 @@ fn program_clauses_for_impl(tcx: TyCtxt<'tcx>, def_id: DefId) -> Clauses<'tcx> {
     tcx.mk_clauses(iter::once(Clause::ForAll(ty::Binder::bind(clause))))
 }
 
-pub fn program_clauses_for_type_def<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Clauses<'tcx> {
+pub fn program_clauses_for_type_def(tcx: TyCtxt<'_>, def_id: DefId) -> Clauses<'_> {
     // Rule WellFormed-Type
     //
     // `struct Ty<P1..Pn> where WC1, ..., WCm`
@@ -411,10 +411,10 @@ pub fn program_clauses_for_type_def<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> C
     tcx.mk_clauses(iter::once(well_formed_clause).chain(from_env_clauses))
 }
 
-pub fn program_clauses_for_associated_type_def<'tcx>(
+pub fn program_clauses_for_associated_type_def(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     item_id: DefId,
-) -> Clauses<'tcx> {
+) -> Clauses<'_> {
     // Rule ProjectionEq-Placeholder
     //
     // ```
@@ -549,10 +549,10 @@ pub fn program_clauses_for_associated_type_def<'tcx>(
     tcx.mk_clauses(clauses)
 }
 
-pub fn program_clauses_for_associated_type_value<'tcx>(
+pub fn program_clauses_for_associated_type_value(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     item_id: DefId,
-) -> Clauses<'tcx> {
+) -> Clauses<'_> {
     // Rule Normalize-From-Impl (see rustc guide)
     //
     // ```
@@ -611,7 +611,7 @@ pub fn program_clauses_for_associated_type_value<'tcx>(
     tcx.mk_clauses(iter::once(normalize_clause))
 }
 
-pub fn dump_program_clauses<'tcx>(tcx: TyCtxt<'tcx>) {
+pub fn dump_program_clauses(tcx: TyCtxt<'_>) {
     if !tcx.features().rustc_attrs {
         return;
     }

src/librustc_typeck/check/method/suggest.rs

@@ -775,12 +775,12 @@ impl Ord for TraitInfo {
 }
 
 /// Retrieves all traits in this crate and any dependent crates.
-pub fn all_traits<'tcx>(tcx: TyCtxt<'tcx>) -> Vec<TraitInfo> {
+pub fn all_traits(tcx: TyCtxt<'_>) -> Vec<TraitInfo> {
     tcx.all_traits(LOCAL_CRATE).iter().map(|&def_id| TraitInfo { def_id }).collect()
 }
 
 /// Computes all traits in this crate and any dependent crates.
-fn compute_all_traits<'tcx>(tcx: TyCtxt<'tcx>) -> Vec<DefId> {
+fn compute_all_traits(tcx: TyCtxt<'_>) -> Vec<DefId> {
     use hir::itemlikevisit;
 
     let mut traits = vec![];

src/librustc_typeck/check_unused.rs

@@ -13,7 +13,7 @@ use rustc::util::nodemap::DefIdSet;
 
 use rustc_data_structures::fx::FxHashMap;
 
-pub fn check_crate<'tcx>(tcx: TyCtxt<'tcx>) {
+pub fn check_crate(tcx: TyCtxt<'_>) {
     let mut used_trait_imports = DefIdSet::default();
     for &body_id in tcx.hir().krate().bodies.keys() {
         let item_def_id = tcx.hir().body_owner_def_id(body_id);
@@ -70,7 +70,7 @@ impl CheckVisitor<'tcx> {
     }
 }
 
-fn unused_crates_lint<'tcx>(tcx: TyCtxt<'tcx>) {
+fn unused_crates_lint(tcx: TyCtxt<'_>) {
     let lint = lint::builtin::UNUSED_EXTERN_CRATES;
 
     // Collect first the crates that are completely unused.  These we

src/librustc_typeck/collect.rs

@@ -56,7 +56,7 @@ struct OnlySelfBounds(bool);
 ///////////////////////////////////////////////////////////////////////////
 // Main entry point
 
-fn collect_mod_item_types<'tcx>(tcx: TyCtxt<'tcx>, module_def_id: DefId) {
+fn collect_mod_item_types(tcx: TyCtxt<'_>, module_def_id: DefId) {
     tcx.hir().visit_item_likes_in_module(
         module_def_id,
         &mut CollectItemTypesVisitor { tcx }.as_deep_visitor()
@@ -253,10 +253,10 @@ impl AstConv<'tcx> for ItemCtxt<'tcx> {
     }
 }
 
-fn type_param_predicates<'tcx>(
+fn type_param_predicates(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     (item_def_id, def_id): (DefId, DefId),
-) -> &'tcx ty::GenericPredicates<'tcx> {
+) -> &ty::GenericPredicates<'_> {
     use rustc::hir::*;
 
     // In the AST, bounds can derive from two places. Either
@@ -381,7 +381,7 @@ impl ItemCtxt<'tcx> {
 /// parameter with ID `param_id`. We use this so as to avoid running
 /// `ast_ty_to_ty`, because we want to avoid triggering an all-out
 /// conversion of the type to avoid inducing unnecessary cycles.
-fn is_param<'tcx>(tcx: TyCtxt<'tcx>, ast_ty: &hir::Ty, param_id: hir::HirId) -> bool {
+fn is_param(tcx: TyCtxt<'_>, ast_ty: &hir::Ty, param_id: hir::HirId) -> bool {
     if let hir::TyKind::Path(hir::QPath::Resolved(None, ref path)) = ast_ty.node {
         match path.res {
             Res::SelfTy(Some(def_id), None) | Res::Def(DefKind::TyParam, def_id) => {
@@ -394,7 +394,7 @@ fn is_param<'tcx>(tcx: TyCtxt<'tcx>, ast_ty: &hir::Ty, param_id: hir::HirId) ->
     }
 }
 
-fn convert_item<'tcx>(tcx: TyCtxt<'tcx>, item_id: hir::HirId) {
+fn convert_item(tcx: TyCtxt<'_>, item_id: hir::HirId) {
     let it = tcx.hir().expect_item(item_id);
     debug!("convert: item {} with id {}", it.ident, it.hir_id);
     let def_id = tcx.hir().local_def_id_from_hir_id(item_id);
@@ -476,7 +476,7 @@ fn convert_item<'tcx>(tcx: TyCtxt<'tcx>, item_id: hir::HirId) {
     }
 }
 
-fn convert_trait_item<'tcx>(tcx: TyCtxt<'tcx>, trait_item_id: hir::HirId) {
+fn convert_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::HirId) {
     let trait_item = tcx.hir().expect_trait_item(trait_item_id);
     let def_id = tcx.hir().local_def_id_from_hir_id(trait_item.hir_id);
     tcx.generics_of(def_id);
@@ -497,7 +497,7 @@ fn convert_trait_item<'tcx>(tcx: TyCtxt<'tcx>, trait_item_id: hir::HirId) {
     tcx.predicates_of(def_id);
 }
 
-fn convert_impl_item<'tcx>(tcx: TyCtxt<'tcx>, impl_item_id: hir::HirId) {
+fn convert_impl_item(tcx: TyCtxt<'_>, impl_item_id: hir::HirId) {
     let def_id = tcx.hir().local_def_id_from_hir_id(impl_item_id);
     tcx.generics_of(def_id);
     tcx.type_of(def_id);
@@ -507,7 +507,7 @@ fn convert_impl_item<'tcx>(tcx: TyCtxt<'tcx>, impl_item_id: hir::HirId) {
     }
 }
 
-fn convert_variant_ctor<'tcx>(tcx: TyCtxt<'tcx>, ctor_id: hir::HirId) {
+fn convert_variant_ctor(tcx: TyCtxt<'_>, ctor_id: hir::HirId) {
     let def_id = tcx.hir().local_def_id_from_hir_id(ctor_id);
     tcx.generics_of(def_id);
     tcx.type_of(def_id);
@@ -562,8 +562,8 @@ fn convert_enum_variant_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, variants:
     }
 }
 
-fn convert_variant<'tcx>(
+fn convert_variant(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     variant_did: Option<DefId>,
     ctor_did: Option<DefId>,
     ident: Ident,
@@ -619,7 +619,7 @@ fn convert_variant<'tcx>(
     )
 }
 
-fn adt_def<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::AdtDef {
+fn adt_def(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::AdtDef {
     use rustc::hir::*;
 
     let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap();
@@ -686,10 +686,10 @@ fn adt_def<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::AdtDef {
 /// Ensures that the super-predicates of the trait with a `DefId`
 /// of `trait_def_id` are converted and stored. This also ensures that
 /// the transitive super-predicates are converted.
-fn super_predicates_of<'tcx>(
+fn super_predicates_of(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     trait_def_id: DefId,
-) -> &'tcx ty::GenericPredicates<'tcx> {
+) -> &ty::GenericPredicates<'_> {
     debug!("super_predicates(trait_def_id={:?})", trait_def_id);
     let trait_hir_id = tcx.hir().as_local_hir_id(trait_def_id).unwrap();
 
@@ -740,7 +740,7 @@ fn super_predicates_of<'tcx>(
     })
 }
 
-fn trait_def<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::TraitDef {
+fn trait_def(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::TraitDef {
     let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap();
     let item = tcx.hir().expect_item(hir_id);
 
@@ -879,7 +879,7 @@ fn has_late_bound_regions<'tcx>(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option<S
     }
 }
 
-fn generics_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::Generics {
+fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::Generics {
     use rustc::hir::*;
 
     let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap();
@@ -1122,7 +1122,7 @@ fn generics_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::Generics {
     })
 }
 
-fn report_assoc_ty_on_inherent_impl<'tcx>(tcx: TyCtxt<'tcx>, span: Span) {
+fn report_assoc_ty_on_inherent_impl(tcx: TyCtxt<'_>, span: Span) {
     span_err!(
         tcx.sess,
         span,
@@ -1131,7 +1131,7 @@ fn report_assoc_ty_on_inherent_impl<'tcx>(tcx: TyCtxt<'tcx>, span: Span) {
     );
 }
 
-fn type_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Ty<'tcx> {
+fn type_of(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> {
     checked_type_of(tcx, def_id, true).unwrap()
 }
 
@@ -1139,7 +1139,7 @@ fn type_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Ty<'tcx> {
 ///
 /// If you want to fail anyway, you can set the `fail` parameter to true, but in this case,
 /// you'd better just call [`type_of`] directly.
-pub fn checked_type_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, fail: bool) -> Option<Ty<'tcx>> {
+pub fn checked_type_of(tcx: TyCtxt<'_>, def_id: DefId, fail: bool) -> Option<Ty<'_>> {
     use rustc::hir::*;
 
     let hir_id = match tcx.hir().as_local_hir_id(def_id) {
@@ -1464,7 +1464,7 @@ pub fn checked_type_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, fail: bool) -> Op
     })
 }
 
-fn find_existential_constraints<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Ty<'tcx> {
+fn find_existential_constraints(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> {
     use rustc::hir::{ImplItem, Item, TraitItem};
 
     debug!("find_existential_constraints({:?})", def_id);
@@ -1682,7 +1682,7 @@ fn find_existential_constraints<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Ty<'t
     }
 }
 
-fn fn_sig<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> ty::PolyFnSig<'tcx> {
+fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
     use rustc::hir::*;
     use rustc::hir::Node::*;
 
@@ -1758,7 +1758,7 @@ fn fn_sig<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> ty::PolyFnSig<'tcx> {
     }
 }
 
-fn impl_trait_ref<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Option<ty::TraitRef<'tcx>> {
+fn impl_trait_ref(tcx: TyCtxt<'_>, def_id: DefId) -> Option<ty::TraitRef<'_>> {
     let icx = ItemCtxt::new(tcx, def_id);
 
     let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap();
@@ -1773,7 +1773,7 @@ fn impl_trait_ref<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Option<ty::TraitRef
     }
 }
 
-fn impl_polarity<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> hir::ImplPolarity {
+fn impl_polarity(tcx: TyCtxt<'_>, def_id: DefId) -> hir::ImplPolarity {
     let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap();
     match tcx.hir().expect_item(hir_id).node {
         hir::ItemKind::Impl(_, polarity, ..) => polarity,
@@ -1804,10 +1804,10 @@ fn early_bound_lifetimes_from_generics<'a, 'tcx: 'a>(
 /// Returns a list of type predicates for the definition with ID `def_id`, including inferred
 /// lifetime constraints. This includes all predicates returned by `explicit_predicates_of`, plus
 /// inferred constraints concerning which regions outlive other regions.
-fn predicates_defined_on<'tcx>(
+fn predicates_defined_on(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     def_id: DefId,
-) -> &'tcx ty::GenericPredicates<'tcx> {
+) -> &ty::GenericPredicates<'_> {
     debug!("predicates_defined_on({:?})", def_id);
     let mut result = tcx.explicit_predicates_of(def_id);
     debug!(
@@ -1834,7 +1834,7 @@ fn predicates_defined_on<'tcx>(
 /// Returns a list of all type predicates (explicit and implicit) for the definition with
 /// ID `def_id`. This includes all predicates returned by `predicates_defined_on`, plus
 /// `Self: Trait` predicates for traits.
-fn predicates_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::GenericPredicates<'tcx> {
+fn predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::GenericPredicates<'_> {
     let mut result = tcx.predicates_defined_on(def_id);
 
     if tcx.is_trait(def_id) {
@@ -1861,10 +1861,10 @@ fn predicates_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::GenericPre
 
 /// Returns a list of user-specified type predicates for the definition with ID `def_id`.
 /// N.B., this does not include any implied/inferred constraints.
-fn explicit_predicates_of<'tcx>(
+fn explicit_predicates_of(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     def_id: DefId,
-) -> &'tcx ty::GenericPredicates<'tcx> {
+) -> &ty::GenericPredicates<'_> {
     use rustc::hir::*;
     use rustc_data_structures::fx::FxHashSet;
 
@@ -2271,7 +2271,7 @@ fn compute_sig_of_foreign_fn_decl<'tcx>(
     fty
 }
 
-fn is_foreign_item<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool {
+fn is_foreign_item(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
     match tcx.hir().get_if_local(def_id) {
         Some(Node::ForeignItem(..)) => true,
         Some(_) => false,
@@ -2279,7 +2279,7 @@ fn is_foreign_item<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool {
     }
 }
 
-fn static_mutability<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Option<hir::Mutability> {
+fn static_mutability(tcx: TyCtxt<'_>, def_id: DefId) -> Option<hir::Mutability> {
     match tcx.hir().get_if_local(def_id) {
         Some(Node::Item(&hir::Item {
             node: hir::ItemKind::Static(_, mutbl, _), ..
@@ -2387,7 +2387,7 @@ fn from_target_feature(
     }
 }
 
-fn linkage_by_name<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, name: &str) -> Linkage {
+fn linkage_by_name(tcx: TyCtxt<'_>, def_id: DefId, name: &str) -> Linkage {
     use rustc::mir::mono::Linkage::*;
 
     // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
@@ -2422,7 +2422,7 @@ fn linkage_by_name<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, name: &str) -> Linkag
     }
 }
 
-fn codegen_fn_attrs<'tcx>(tcx: TyCtxt<'tcx>, id: DefId) -> CodegenFnAttrs {
+fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs {
     let attrs = tcx.get_attrs(id);
 
     let mut codegen_fn_attrs = CodegenFnAttrs::new();

src/librustc_typeck/impl_wf_check.rs

@@ -49,7 +49,7 @@ use syntax_pos::Span;
 /// impl<'a> Trait<Foo> for Bar { type X = &'a i32; }
 /// //   ^ 'a is unused and appears in assoc type, error
 /// ```
-pub fn impl_wf_check<'tcx>(tcx: TyCtxt<'tcx>) {
+pub fn impl_wf_check(tcx: TyCtxt<'_>) {
     // We will tag this as part of the WF check -- logically, it is,
     // but it's one that we must perform earlier than the rest of
     // WfCheck.
@@ -58,7 +58,7 @@ pub fn impl_wf_check<'tcx>(tcx: TyCtxt<'tcx>) {
     }
 }
 
-fn check_mod_impl_wf<'tcx>(tcx: TyCtxt<'tcx>, module_def_id: DefId) {
+fn check_mod_impl_wf(tcx: TyCtxt<'_>, module_def_id: DefId) {
     tcx.hir().visit_item_likes_in_module(
         module_def_id,
         &mut ImplWfCheck { tcx }
@@ -92,8 +92,8 @@ impl ItemLikeVisitor<'tcx> for ImplWfCheck<'tcx> {
     fn visit_impl_item(&mut self, _impl_item: &'tcx hir::ImplItem) { }
 }
 
-fn enforce_impl_params_are_constrained<'tcx>(
+fn enforce_impl_params_are_constrained(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     impl_def_id: DefId,
     impl_item_refs: &[hir::ImplItemRef],
 ) {
@@ -183,7 +183,7 @@ fn report_unused_parameter(tcx: TyCtxt<'_>, span: Span, kind: &str, name: &str)
 }
 
 /// Enforce that we do not have two items in an impl with the same name.
-fn enforce_impl_items_are_distinct<'tcx>(tcx: TyCtxt<'tcx>, impl_item_refs: &[hir::ImplItemRef]) {
+fn enforce_impl_items_are_distinct(tcx: TyCtxt<'_>, impl_item_refs: &[hir::ImplItemRef]) {
     let mut seen_type_items = FxHashMap::default();
     let mut seen_value_items = FxHashMap::default();
     for impl_item_ref in impl_item_refs {

src/librustc_typeck/lib.rs

@@ -161,7 +161,7 @@ fn require_same_types<'tcx>(
     })
 }
 
-fn check_main_fn_ty<'tcx>(tcx: TyCtxt<'tcx>, main_def_id: DefId) {
+fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: DefId) {
     let main_id = tcx.hir().as_local_hir_id(main_def_id).unwrap();
     let main_span = tcx.def_span(main_def_id);
     let main_t = tcx.type_of(main_def_id);
@@ -226,7 +226,7 @@ fn check_main_fn_ty<'tcx>(tcx: TyCtxt<'tcx>, main_def_id: DefId) {
     }
 }
 
-fn check_start_fn_ty<'tcx>(tcx: TyCtxt<'tcx>, start_def_id: DefId) {
+fn check_start_fn_ty(tcx: TyCtxt<'_>, start_def_id: DefId) {
     let start_id = tcx.hir().as_local_hir_id(start_def_id).unwrap();
     let start_span = tcx.def_span(start_def_id);
     let start_t = tcx.type_of(start_def_id);
@@ -283,7 +283,7 @@ fn check_start_fn_ty<'tcx>(tcx: TyCtxt<'tcx>, start_def_id: DefId) {
     }
 }
 
-fn check_for_entry_fn<'tcx>(tcx: TyCtxt<'tcx>) {
+fn check_for_entry_fn(tcx: TyCtxt<'_>) {
     match tcx.entry_fn(LOCAL_CRATE) {
         Some((def_id, EntryFnType::Main)) => check_main_fn_ty(tcx, def_id),
         Some((def_id, EntryFnType::Start)) => check_start_fn_ty(tcx, def_id),
@@ -300,7 +300,7 @@ pub fn provide(providers: &mut Providers<'_>) {
     impl_wf_check::provide(providers);
 }
 
-pub fn check_crate<'tcx>(tcx: TyCtxt<'tcx>) -> Result<(), ErrorReported> {
+pub fn check_crate(tcx: TyCtxt<'_>) -> Result<(), ErrorReported> {
     tcx.sess.profiler(|p| p.start_activity("type-check crate"));
 
     // this ensures that later parts of type checking can assume that items

src/librustc_typeck/outlives/mod.rs

@@ -20,10 +20,10 @@ pub fn provide(providers: &mut Providers<'_>) {
     };
 }
 
-fn inferred_outlives_of<'tcx>(
+fn inferred_outlives_of(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     item_def_id: DefId,
-) -> &'tcx [ty::Predicate<'tcx>] {
+) -> &[ty::Predicate<'_>] {
     let id = tcx
         .hir()
         .as_local_hir_id(item_def_id)
@@ -70,10 +70,10 @@ fn inferred_outlives_of<'tcx>(
     }
 }
 
-fn inferred_outlives_crate<'tcx>(
+fn inferred_outlives_crate(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     crate_num: CrateNum,
-) -> &'tcx CratePredicatesMap<'tcx> {
+) -> &CratePredicatesMap<'_> {
     assert_eq!(crate_num, LOCAL_CRATE);
 
     // Compute a map from each struct/enum/union S to the **explicit**

src/librustc_typeck/outlives/test.rs

@@ -3,7 +3,7 @@ use rustc::hir::itemlikevisit::ItemLikeVisitor;
 use rustc::ty::TyCtxt;
 use syntax::symbol::sym;
 
-pub fn test_inferred_outlives<'tcx>(tcx: TyCtxt<'tcx>) {
+pub fn test_inferred_outlives(tcx: TyCtxt<'_>) {
     tcx.hir()
        .krate()
        .visit_all_item_likes(&mut OutlivesTest { tcx });

src/librustc_typeck/outlives/utils.rs

@@ -125,7 +125,7 @@ pub fn insert_outlives_predicate<'tcx>(
     }
 }
 
-fn is_free_region<'tcx>(tcx: TyCtxt<'tcx>, region: Region<'_>) -> bool {
+fn is_free_region(tcx: TyCtxt<'_>, region: Region<'_>) -> bool {
     // First, screen for regions that might appear in a type header.
     match region {
         // These correspond to `T: 'a` relationships:

src/librustc_typeck/variance/mod.rs

@@ -34,7 +34,7 @@ pub fn provide(providers: &mut Providers<'_>) {
     };
 }
 
-fn crate_variances<'tcx>(tcx: TyCtxt<'tcx>, crate_num: CrateNum) -> &'tcx CrateVariancesMap<'tcx> {
+fn crate_variances(tcx: TyCtxt<'_>, crate_num: CrateNum) -> &CrateVariancesMap<'_> {
     assert_eq!(crate_num, LOCAL_CRATE);
     let mut arena = arena::TypedArena::default();
     let terms_cx = terms::determine_parameters_to_be_inferred(tcx, &mut arena);
@@ -42,7 +42,7 @@ fn crate_variances<'tcx>(tcx: TyCtxt<'tcx>, crate_num: CrateNum) -> &'tcx CrateV
     tcx.arena.alloc(solve::solve_constraints(constraints_cx))
 }
 
-fn variances_of<'tcx>(tcx: TyCtxt<'tcx>, item_def_id: DefId) -> &'tcx [ty::Variance] {
+fn variances_of(tcx: TyCtxt<'_>, item_def_id: DefId) -> &[ty::Variance] {
     let id = tcx.hir().as_local_hir_id(item_def_id).expect("expected local def-id");
     let unsupported = || {
         // Variance not relevant.

src/librustc_typeck/variance/test.rs

@@ -3,7 +3,7 @@ use rustc::hir::itemlikevisit::ItemLikeVisitor;
 use rustc::ty::TyCtxt;
 use syntax::symbol::sym;
 
-pub fn test_variance<'tcx>(tcx: TyCtxt<'tcx>) {
+pub fn test_variance(tcx: TyCtxt<'_>) {
     tcx.hir().krate().visit_all_item_likes(&mut VarianceTest { tcx });
 }
 

src/librustdoc/markdown.rs

@@ -17,7 +17,7 @@ use crate::html::markdown::{ErrorCodes, IdMap, Markdown, MarkdownWithToc, find_t
 use crate::test::{TestOptions, Collector};
 
 /// Separate any lines at the start of the file that begin with `# ` or `%`.
-fn extract_leading_metadata<'a>(s: &'a str) -> (Vec<&'a str>, &'a str) {
+fn extract_leading_metadata(s: &str) -> (Vec<&str>, &str) {
     let mut metadata = Vec::new();
     let mut count = 0;
 

src/libserialize/json.rs

@@ -1031,7 +1031,7 @@ impl Json {
 
      /// If the Json value is an Object, returns the value associated with the provided key.
     /// Otherwise, returns None.
-    pub fn find<'a>(&'a self, key: &str) -> Option<&'a Json>{
+    pub fn find(&self, key: &str) -> Option<&Json> {
         match *self {
             Json::Object(ref map) => map.get(key),
             _ => None
@@ -1052,7 +1052,7 @@ impl Json {
     /// If the Json value is an Object, performs a depth-first search until
     /// a value associated with the provided key is found. If no value is found
     /// or the Json value is not an Object, returns `None`.
-    pub fn search<'a>(&'a self, key: &str) -> Option<&'a Json> {
+    pub fn search(&self, key: &str) -> Option<&Json> {
         match self {
             &Json::Object(ref map) => {
                 match map.get(key) {

src/libsyntax_ext/assert.rs

@@ -131,7 +131,7 @@ fn parse_assert<'a>(
     Ok(Assert { cond_expr, custom_message })
 }
 
-fn parse_custom_message<'a>(parser: &mut Parser<'a>) -> Option<TokenStream> {
+fn parse_custom_message(parser: &mut Parser<'_>) -> Option<TokenStream> {
     let ts = parser.parse_tokens();
     if !ts.is_empty() {
         Some(ts)