Rollup merge of #88182 - spastorino:use-trait-in-tait-tests, r=oli-obk

We meant to use a trait instead of lifetime here

r? `@oli-obk`

Related to #86727

src/test/ui/type-alias-impl-trait/generic_underconstrained.rs

@@ -3,8 +3,7 @@
 fn main() {}
 
 trait Trait {}
-type Underconstrained<T: Trait> = impl 'static;
-//~^ ERROR: at least one trait must be specified
+type Underconstrained<T: Trait> = impl Send;
 
 // no `Trait` bound
 fn underconstrain<T>(_: T) -> Underconstrained<T> {

src/test/ui/type-alias-impl-trait/generic_underconstrained.stderr

-error: at least one trait must be specified
-  --> $DIR/generic_underconstrained.rs:6:35
-   |
-LL | type Underconstrained<T: Trait> = impl 'static;
-   |                                   ^^^^^^^^^^^^
-
 error[E0277]: the trait bound `T: Trait` is not satisfied
-  --> $DIR/generic_underconstrained.rs:10:31
+  --> $DIR/generic_underconstrained.rs:9:31
    |
 LL | fn underconstrain<T>(_: T) -> Underconstrained<T> {
    |                               ^^^^^^^^^^^^^^^^^^^ the trait `Trait` is not implemented for `T`
@@ -13,13 +7,13 @@ LL | fn underconstrain<T>(_: T) -> Underconstrained<T> {
 note: required by a bound in `Underconstrained`
   --> $DIR/generic_underconstrained.rs:6:26
    |
-LL | type Underconstrained<T: Trait> = impl 'static;
+LL | type Underconstrained<T: Trait> = impl Send;
    |                          ^^^^^ required by this bound in `Underconstrained`
 help: consider restricting type parameter `T`
    |
 LL | fn underconstrain<T: Trait>(_: T) -> Underconstrained<T> {
    |                    +++++++
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0277`.

src/test/ui/type-alias-impl-trait/generic_underconstrained2.rs

@@ -2,8 +2,7 @@
 
 fn main() {}
 
-type Underconstrained<T: std::fmt::Debug> = impl 'static;
-//~^ ERROR: at least one trait must be specified
+type Underconstrained<T: std::fmt::Debug> = impl Send;
 
 // not a defining use, because it doesn't define *all* possible generics
 fn underconstrained<U>(_: U) -> Underconstrained<U> {
@@ -11,8 +10,7 @@ fn underconstrained<U>(_: U) -> Underconstrained<U> {
     5u32
 }
 
-type Underconstrained2<T: std::fmt::Debug> = impl 'static;
-//~^ ERROR: at least one trait must be specified
+type Underconstrained2<T: std::fmt::Debug> = impl Send;
 
 // not a defining use, because it doesn't define *all* possible generics
 fn underconstrained2<U, V>(_: U, _: V) -> Underconstrained2<V> {

src/test/ui/type-alias-impl-trait/generic_underconstrained2.stderr

-error: at least one trait must be specified
-  --> $DIR/generic_underconstrained2.rs:5:45
-   |
-LL | type Underconstrained<T: std::fmt::Debug> = impl 'static;
-   |                                             ^^^^^^^^^^^^
-
-error: at least one trait must be specified
-  --> $DIR/generic_underconstrained2.rs:14:46
-   |
-LL | type Underconstrained2<T: std::fmt::Debug> = impl 'static;
-   |                                              ^^^^^^^^^^^^
-
 error[E0277]: `U` doesn't implement `Debug`
-  --> $DIR/generic_underconstrained2.rs:9:33
+  --> $DIR/generic_underconstrained2.rs:8:33
    |
 LL | fn underconstrained<U>(_: U) -> Underconstrained<U> {
    |                                 ^^^^^^^^^^^^^^^^^^^ `U` cannot be formatted using `{:?}` because it doesn't implement `Debug`
@@ -19,7 +7,7 @@ LL | fn underconstrained<U>(_: U) -> Underconstrained<U> {
 note: required by a bound in `Underconstrained`
   --> $DIR/generic_underconstrained2.rs:5:26
    |
-LL | type Underconstrained<T: std::fmt::Debug> = impl 'static;
+LL | type Underconstrained<T: std::fmt::Debug> = impl Send;
    |                          ^^^^^^^^^^^^^^^ required by this bound in `Underconstrained`
 help: consider restricting type parameter `U`
    |
@@ -27,21 +15,21 @@ LL | fn underconstrained<U: std::fmt::Debug>(_: U) -> Underconstrained<U> {
    |                      +++++++++++++++++
 
 error[E0277]: `V` doesn't implement `Debug`
-  --> $DIR/generic_underconstrained2.rs:18:43
+  --> $DIR/generic_underconstrained2.rs:16:43
    |
 LL | fn underconstrained2<U, V>(_: U, _: V) -> Underconstrained2<V> {
    |                                           ^^^^^^^^^^^^^^^^^^^^ `V` cannot be formatted using `{:?}` because it doesn't implement `Debug`
    |
 note: required by a bound in `Underconstrained2`
-  --> $DIR/generic_underconstrained2.rs:14:27
+  --> $DIR/generic_underconstrained2.rs:13:27
    |
-LL | type Underconstrained2<T: std::fmt::Debug> = impl 'static;
+LL | type Underconstrained2<T: std::fmt::Debug> = impl Send;
    |                           ^^^^^^^^^^^^^^^ required by this bound in `Underconstrained2`
 help: consider restricting type parameter `V`
    |
 LL | fn underconstrained2<U, V: std::fmt::Debug>(_: U, _: V) -> Underconstrained2<V> {
    |                          +++++++++++++++++
 
-error: aborting due to 4 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0277`.