rust/tests/ui/traits/bound/impl-comparison-duplicates.rs

//@ check-pass
// Tests that type parameter bounds on an implementation need not match the
// trait exactly, as long as the implementation doesn't demand *more* bounds
// than the trait.


trait A {
    fn foo<T: Eq + Ord>(&self);
}

impl A for isize {
    fn foo<T: Ord>(&self) {} // Ord implies Eq, so this is ok.
}

fn main() {}
Update tests 2024-02-07 02:42:01 +00:00			`//@ check-pass`
librustc: Properly compare implementation method type parameter bounds with the corresponding trait parameter bounds. This is a version of the patch in PR #12611 by Florian Hahn, modified to address Niko's feedback. It does not address the issue of duplicate type parameter bounds, nor does it address the issue of implementation-defined methods that contain fewer bounds than the trait, because Niko's review indicates that this should not be necessary (and indeed I believe it is not). A test has been added to ensure that this works. This will break code like: trait Foo { fn bar<T:Baz>(); } impl Foo for Boo { fn bar<T:Baz + Quux>() { ... } // ^~~~ ERROR } This will be rejected because the implementation requires more bounds than the trait. It can be fixed by either adding the missing bound to the trait: trait Foo { fn bar<T:Baz + Quux>(); // ^~~~ } impl Foo for Boo { fn bar<T:Baz + Quux>() { ... } // OK } Or by removing the bound from the impl: trait Foo { fn bar<T:Baz>(); } impl Foo for Boo { fn bar<T:Baz>() { ... } // OK // ^ remove Quux } This patch imports the relevant tests from #2687, as well as the test case in #5886, which is fixed as well by this patch. Closes #2687. Closes #5886. [breaking-change] 2014-07-02 04:59:16 +00:00			`// Tests that type parameter bounds on an implementation need not match the`
			`// trait exactly, as long as the implementation doesn't demand more bounds`
			`// than the trait.`

rustdoc: Replace no-pretty-expanded with pretty-expanded Now that features must be declared expanded source often does not compile. This adds 'pretty-expanded' to a bunch of test cases that still work. 2015-03-22 20:13:15 +00:00
librustc: Properly compare implementation method type parameter bounds with the corresponding trait parameter bounds. This is a version of the patch in PR #12611 by Florian Hahn, modified to address Niko's feedback. It does not address the issue of duplicate type parameter bounds, nor does it address the issue of implementation-defined methods that contain fewer bounds than the trait, because Niko's review indicates that this should not be necessary (and indeed I believe it is not). A test has been added to ensure that this works. This will break code like: trait Foo { fn bar<T:Baz>(); } impl Foo for Boo { fn bar<T:Baz + Quux>() { ... } // ^~~~ ERROR } This will be rejected because the implementation requires more bounds than the trait. It can be fixed by either adding the missing bound to the trait: trait Foo { fn bar<T:Baz + Quux>(); // ^~~~ } impl Foo for Boo { fn bar<T:Baz + Quux>() { ... } // OK } Or by removing the bound from the impl: trait Foo { fn bar<T:Baz>(); } impl Foo for Boo { fn bar<T:Baz>() { ... } // OK // ^ remove Quux } This patch imports the relevant tests from #2687, as well as the test case in #5886, which is fixed as well by this patch. Closes #2687. Closes #5886. [breaking-change] 2014-07-02 04:59:16 +00:00			`trait A {`
			`fn foo<T: Eq + Ord>(&self);`
			`}`

Mass rename uint/int to usize/isize Now that support has been removed, all lingering use cases are renamed. 2015-03-26 00:06:52 +00:00			`impl A for isize {`
Implement generalized object and type parameter bounds (Fixes #16462) 2014-08-28 01:46:52 +00:00			`fn foo<T: Ord>(&self) {} // Ord implies Eq, so this is ok.`
librustc: Properly compare implementation method type parameter bounds with the corresponding trait parameter bounds. This is a version of the patch in PR #12611 by Florian Hahn, modified to address Niko's feedback. It does not address the issue of duplicate type parameter bounds, nor does it address the issue of implementation-defined methods that contain fewer bounds than the trait, because Niko's review indicates that this should not be necessary (and indeed I believe it is not). A test has been added to ensure that this works. This will break code like: trait Foo { fn bar<T:Baz>(); } impl Foo for Boo { fn bar<T:Baz + Quux>() { ... } // ^~~~ ERROR } This will be rejected because the implementation requires more bounds than the trait. It can be fixed by either adding the missing bound to the trait: trait Foo { fn bar<T:Baz + Quux>(); // ^~~~ } impl Foo for Boo { fn bar<T:Baz + Quux>() { ... } // OK } Or by removing the bound from the impl: trait Foo { fn bar<T:Baz>(); } impl Foo for Boo { fn bar<T:Baz>() { ... } // OK // ^ remove Quux } This patch imports the relevant tests from #2687, as well as the test case in #5886, which is fixed as well by this patch. Closes #2687. Closes #5886. [breaking-change] 2014-07-02 04:59:16 +00:00			`}`

			`fn main() {}`