Auto merge of #61891 - eddyb:lifetime-cleanups, r=oli-obk

rustc: remove 'x: 'y bounds (except where necessary or from comments/strings).

This PR removes all lifetime-lifetime "outlives" bounds (e.g. `'tcx: 'a`) bounds except a few necessary ones (see the `reintroduce lifetime bounds where necessary` commit).

Some of these bounds kept around otherwise-unused lifetimes (e.g. `<'a, 'tcx: 'a>` followed by uses of `'tcx` but not `'a`) - these lifetimes (i.e. `'a`) were then removed.
(maybe they should be considered unused by the lint? cc @matthewjasper @zackmdavis)

r? @oli-obk cc @rust-lang/compiler

3 files changed, 5 insertions, 5 deletions

diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 3fa96c60bff..d433e6c5a89 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -242,7 +242,7 @@ impl Invocation {
     }
 }
 
-pub struct MacroExpander<'a, 'b:'a> {
+pub struct MacroExpander<'a, 'b> {
     pub cx: &'a mut ExtCtxt<'b>,
     monotonic: bool, // cf. `cx.monotonic_expander()`
 }
@@ -1031,7 +1031,7 @@ impl<'a> Parser<'a> {
     }
 }
 
-struct InvocationCollector<'a, 'b: 'a> {
+struct InvocationCollector<'a, 'b> {
     cx: &'a mut ExtCtxt<'b>,
     cfg: StripUnconfigured<'a>,
     invocations: Vec<Invocation>,
diff --git a/src/libsyntax/ext/placeholders.rs b/src/libsyntax/ext/placeholders.rs
index c56c156182b..b2b8bfb09b4 100644
--- a/src/libsyntax/ext/placeholders.rs
+++ b/src/libsyntax/ext/placeholders.rs
@@ -69,7 +69,7 @@ pub fn placeholder(kind: AstFragmentKind, id: ast::NodeId) -> AstFragment {
     }
 }
 
-pub struct PlaceholderExpander<'a, 'b: 'a> {
+pub struct PlaceholderExpander<'a, 'b> {
     expanded_fragments: FxHashMap<ast::NodeId, AstFragment>,
     cx: &'a mut ExtCtxt<'b>,
     monotonic: bool,
diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs
index 4758b6a50e5..d5da4c920bc 100644
--- a/src/libsyntax/ext/tt/macro_parser.rs
+++ b/src/libsyntax/ext/tt/macro_parser.rs
@@ -156,7 +156,7 @@ type NamedMatchVec = SmallVec<[NamedMatch; 4]>;
 /// all the elements in that `SmallVec` strictly outlive the root stack slot
 /// lifetime. By separating `'tt` from `'root`, we can show that.
 #[derive(Clone)]
-struct MatcherPos<'root, 'tt: 'root> {
+struct MatcherPos<'root, 'tt> {
     /// The token or sequence of tokens that make up the matcher
     top_elts: TokenTreeOrTokenTreeSlice<'tt>,
 
@@ -233,7 +233,7 @@ impl<'root, 'tt> MatcherPos<'root, 'tt> {
 // Therefore, the initial MatcherPos is always allocated on the stack,
 // subsequent ones (of which there aren't that many) are allocated on the heap,
 // and this type is used to encapsulate both cases.
-enum MatcherPosHandle<'root, 'tt: 'root> {
+enum MatcherPosHandle<'root, 'tt> {
     Ref(&'root mut MatcherPos<'root, 'tt>),
     Box(Box<MatcherPos<'root, 'tt>>),
 }