Account for type params with bounds

This commit is contained in:
Esteban Küber 2020-04-05 12:32:34 -07:00
parent 794b644f0b
commit c85fde126e
3 changed files with 30 additions and 6 deletions

View file

@ -24,6 +24,14 @@ fn baz(t: impl std::fmt::Debug, constraints: impl Iterator) {
}
}
fn bat<T: std::fmt::Debug>(t: T, constraints: impl Iterator) {
for constraint in constraints {
qux(t);
qux(constraint);
//~^ ERROR `<impl Iterator as std::iter::Iterator>::Item` doesn't implement `std::fmt::Debug`
}
}
fn qux(_: impl std::fmt::Debug) {}
fn main() {}

View file

@ -43,6 +43,21 @@ help: introduce a type parameter with a trait bound instead of using `impl Trait
LL | fn baz<T: Iterator>(t: impl std::fmt::Debug, constraints: T) where <T as std::iter::Iterator>::Item: std::fmt::Debug {
| ^^^^^^^^^^^^^ ^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to 3 previous errors
error[E0277]: `<impl Iterator as std::iter::Iterator>::Item` doesn't implement `std::fmt::Debug`
--> $DIR/impl-trait-with-missing-bounds.rs:30:13
|
LL | qux(constraint);
| ^^^^^^^^^^ `<impl Iterator as std::iter::Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `std::fmt::Debug`
...
LL | fn qux(_: impl std::fmt::Debug) {}
| --- --------------- required by this bound in `qux`
|
= help: the trait `std::fmt::Debug` is not implemented for `<impl Iterator as std::iter::Iterator>::Item`
help: introduce a type parameter with a trait bound instead of using `impl Trait`
|
LL | fn bat<T: std::fmt::Debug, T: Iterator>(t: T, constraints: T) where <T as std::iter::Iterator>::Item: std::fmt::Debug {
| ^^^^^^^^^^^^^ ^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to 4 previous errors
For more information about this error, try `rustc --explain E0277`.