Skip to content

We meant to use a trait instead of lifetime here #88182

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Aug 22, 2021
Merged

We meant to use a trait instead of lifetime here #88182

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 1 addition & 2 deletions src/test/ui/type-alias-impl-trait/generic_underconstrained.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -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> {
Expand Down
12 changes: 3 additions & 9 deletions src/test/ui/type-alias-impl-trait/generic_underconstrained.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,25 +1,19 @@
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`
|
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`.
6 changes: 2 additions & 4 deletions src/test/ui/type-alias-impl-trait/generic_underconstrained2.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,17 +2,15 @@

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> {
//~^ ERROR `U` doesn't implement `Debug`
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> {
Expand Down
24 changes: 6 additions & 18 deletions src/test/ui/type-alias-impl-trait/generic_underconstrained2.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,47 +1,35 @@
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`
|
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`
|
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`.