examples: Add stricter impl trait bounds #1518
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sdroege
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Sep 29, 2024
| pub trait CatImpl: PetImpl {} | ||
| pub trait CatImpl: PetImpl | ||
| where | ||
| <Self as ObjectSubclass>::Type: IsA<Pet>, |
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This one is not inferred by requiring PetImpl, and PetImpl requiring IsA<Pet>?
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It is required, not inferred. Therefore it is showing an error if not specified.
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error[E0277]: the trait bound `<Self as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet>` is not satisfied
--> examples/virtual_methods/cat.rs:99:20
|
99 | pub trait CatImpl: PetImpl
| ^^^^^^^ the trait `glib::object::IsA<pet::Pet>` is not implemented for `<Self as glib::subclass::types::ObjectSubclass>::Type`
|
note: required by a bound in `pet::PetImpl`
--> examples/virtual_methods/pet.rs:130:37
|
128 | pub trait PetImpl: ObjectImpl
| ------- required by a bound in this trait
129 | where
130 | <Self as ObjectSubclass>::Type: IsA<Pet>,
| ^^^^^^^^ required by this bound in `PetImpl`
help: consider further restricting the associated type
|
101 | <Self as ObjectSubclass>::Type: IsA<Cat>, <Self as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet>
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
error[E0277]: the trait bound `<Obj as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet>` is not satisfied
--> examples/virtual_methods/cat.rs:106:28
|
106 | unsafe impl<Obj: CatImpl + PetImpl> IsSubclassable<Obj> for Cat where
| ^^^^^^^ the trait `glib::object::IsA<pet::Pet>` is not implemented for `<Obj as glib::subclass::types::ObjectSubclass>::Type`
|
note: required by a bound in `pet::PetImpl`
--> examples/virtual_methods/pet.rs:130:37
|
128 | pub trait PetImpl: ObjectImpl
| ------- required by a bound in this trait
129 | where
130 | <Self as ObjectSubclass>::Type: IsA<Pet>,
| ^^^^^^^^ required by this bound in `PetImpl`
help: consider further restricting the associated type
|
107 | <Obj as ObjectSubclass>::Type: IsA<Cat>, <Obj as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet>
| +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
For more information about this error, try `rustc --explain E0277`.
error: could not compile `gtk-rs-examples` (bin "virtual_methods") due to 2 previous errors
examples/virtual_methods/pet.rs
Outdated
| @@ -169,10 +175,13 @@ pub trait PetImplExt: PetImpl { | |||
| } | |||
|
|
|||
| /// The `PetImplExt` trait is implemented for all subclasses that have [`Pet`] in the class hierarchy | |||
| impl<T: PetImpl> PetImplExt for T {} | |||
| impl<T: PetImpl> PetImplExt for T where <Self as ObjectSubclass>::Type: IsA<Pet> {} | |||
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Not necessary (because nothing else can implement this trait) unless the compiler forces you :) It should also be implied via T: PetImpl already
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unless the compiler forces you
It does.
error[E0277]: the trait bound `<Self as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet>` is not satisfied
--> examples/virtual_methods/pet.rs:154:23
|
154 | pub trait PetImplExt: PetImpl {
| ^^^^^^^ the trait `glib::object::IsA<pet::Pet>` is not implemented for `<Self as glib::subclass::types::ObjectSubclass>::Type`
|
note: required by a bound in `pet::PetImpl`
--> examples/virtual_methods/pet.rs:130:37
|
128 | pub trait PetImpl: ObjectImpl
| ------- required by a bound in this trait
129 | where
130 | <Self as ObjectSubclass>::Type: IsA<Pet>,
| ^^^^^^^^ required by this bound in `PetImpl`
help: consider further restricting the associated type
|
154 | pub trait PetImplExt: PetImpl where <Self as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet> {
| ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
error[E0277]: the trait bound `<T as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet>` is not satisfied
--> examples/virtual_methods/pet.rs:175:9
|
175 | impl<T: PetImpl> PetImplExt for T {}
| ^^^^^^^ the trait `glib::object::IsA<pet::Pet>` is not implemented for `<T as glib::subclass::types::ObjectSubclass>::Type`
|
note: required by a bound in `pet::PetImpl`
--> examples/virtual_methods/pet.rs:130:37
|
128 | pub trait PetImpl: ObjectImpl
| ------- required by a bound in this trait
129 | where
130 | <Self as ObjectSubclass>::Type: IsA<Pet>,
| ^^^^^^^^ required by this bound in `PetImpl`
help: consider further restricting the associated type
|
175 | impl<T: PetImpl> PetImplExt for T where <T as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet> {}
| +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
error[E0277]: the trait bound `<Self as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet>` is not satisfied
--> examples/virtual_methods/pet.rs:154:23
|
154 | pub trait PetImplExt: PetImpl {
| ^^^^^^^ the trait `glib::object::IsA<pet::Pet>` is not implemented for `<Self as glib::subclass::types::ObjectSubclass>::Type`
|
note: required by a bound in `pet::PetImpl`
--> examples/virtual_methods/pet.rs:130:37
|
128 | pub trait PetImpl: ObjectImpl
| ------- required by a bound in this trait
129 | where
130 | <Self as ObjectSubclass>::Type: IsA<Pet>,
| ^^^^^^^^ required by this bound in `PetImpl`
help: consider further restricting the associated type
|
156 | fn parent_pet(&self) -> bool where <Self as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet> {
| ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
error[E0277]: the trait bound `<Self as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet>` is not satisfied
--> examples/virtual_methods/pet.rs:154:23
|
154 | pub trait PetImplExt: PetImpl {
| ^^^^^^^ the trait `glib::object::IsA<pet::Pet>` is not implemented for `<Self as glib::subclass::types::ObjectSubclass>::Type`
|
note: required by a bound in `pet::PetImpl`
--> examples/virtual_methods/pet.rs:130:37
|
128 | pub trait PetImpl: ObjectImpl
| ------- required by a bound in this trait
129 | where
130 | <Self as ObjectSubclass>::Type: IsA<Pet>,
| ^^^^^^^^ required by this bound in `PetImpl`
help: consider further restricting the associated type
|
165 | fn parent_feed(&self) where <Self as glib::subclass::types::ObjectSubclass>::Type: glib::object::IsA<pet::Pet> {
| ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
For more information about this error, try `rustc --explain E0277`.
error: could not compile `gtk-rs-examples` (bin "virtual_methods") due to 4 previous errors
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Separates out the examples as those don't introduce breaking changes.
See #1515