update tests + add future compat test

src/test/ui/lub-glb/empty-binder-future-compat.rs

@@ -0,0 +1,22 @@
+// check-pass
+fn lt_in_fn_fn<'a: 'a>() -> fn(fn(&'a ())) {
+ |_| ()
+}
+
+
+fn foo<'a, 'b, 'lower>(v: bool)
+where
+ 'a: 'lower,
+ 'b: 'lower,
+{
+ // if we infer `x` to be higher ranked in the future,
+ // this would cause a type error.
+ let x = match v {
+ true => lt_in_fn_fn::<'a>(),
+ false => lt_in_fn_fn::<'b>(),
+ };
+
+ let _: fn(fn(&'lower())) = x;
+}
+
+fn main() {}

src/test/ui/lub-glb/empty-binders-err.rs

@@ -11,12 +11,10 @@ fn lt_in_contra<'a: 'a>() -> Contra<'a> {
  Contra(|_| ())
 }
 
-fn covariance<'a, 'b, 'upper, 'lower>(v: bool)
+fn covariance<'a, 'b, 'upper>(v: bool)
 where
  'upper: 'a,
  'upper: 'b,
- 'a: 'lower,
- 'b: 'lower,
 
 {
  let _: &'upper () = match v {
@@ -27,10 +25,8 @@ where
  };
 }
 
-fn contra_fn<'a, 'b, 'upper, 'lower>(v: bool)
+fn contra_fn<'a, 'b, 'lower>(v: bool)
 where
- 'upper: 'a,
- 'upper: 'b,
  'a: 'lower,
  'b: 'lower,
 
@@ -43,10 +39,8 @@ where
  };
 }
 
-fn contra_struct<'a, 'b, 'upper, 'lower>(v: bool)
+fn contra_struct<'a, 'b, 'lower>(v: bool)
 where
- 'upper: 'a,
- 'upper: 'b,
  'a: 'lower,
  'b: 'lower,
 

src/test/ui/lub-glb/empty-binders-err.stderr

@@ -1,7 +1,7 @@
 error: lifetime may not live long enough
- --> $DIR/empty-binders-err.rs:22:12
+ --> $DIR/empty-binders-err.rs:20:12
  |
-LL | fn covariance<'a, 'b, 'upper, 'lower>(v: bool)
+LL | fn covariance<'a, 'b, 'upper>(v: bool)
  | -- ------ lifetime `'upper` defined here
  | |
  | lifetime `'a` defined here
@@ -12,9 +12,9 @@ LL | let _: &'upper () = match v {
  = help: consider adding the following bound: `'a: 'upper`
 
 error: lifetime may not live long enough
- --> $DIR/empty-binders-err.rs:22:12
+ --> $DIR/empty-binders-err.rs:20:12
  |
-LL | fn covariance<'a, 'b, 'upper, 'lower>(v: bool)
+LL | fn covariance<'a, 'b, 'upper>(v: bool)
  | -- ------ lifetime `'upper` defined here
  | |
  | lifetime `'b` defined here
@@ -30,10 +30,10 @@ help: the following changes may resolve your lifetime errors
  = help: add bound `'b: 'upper`
 
 error: lifetime may not live long enough
- --> $DIR/empty-binders-err.rs:39:12
+ --> $DIR/empty-binders-err.rs:35:12
  |
-LL | fn contra_fn<'a, 'b, 'upper, 'lower>(v: bool)
- | --  ------ lifetime `'lower` defined here
+LL | fn contra_fn<'a, 'b, 'lower>(v: bool)
+ | -- ------ lifetime `'lower` defined here
  | |
  | lifetime `'a` defined here
 ...
@@ -43,10 +43,10 @@ LL | let _: fn(&'lower ()) = match v {
  = help: consider adding the following bound: `'lower: 'a`
 
 error: lifetime may not live long enough
- --> $DIR/empty-binders-err.rs:54:12
+ --> $DIR/empty-binders-err.rs:48:12
  |
-LL | fn contra_struct<'a, 'b, 'upper, 'lower>(v: bool)
- | --  ------ lifetime `'lower` defined here
+LL | fn contra_struct<'a, 'b, 'lower>(v: bool)
+ | -- ------ lifetime `'lower` defined here
  | |
  | lifetime `'a` defined here
 ...