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// Check that when there are vacuous predicates in the environment
// (which make a fn uncallable) we don't erroneously cache those and
// then consider them satisfied elsewhere. The current technique for
// doing this is to not use global caches when there is a chance that
// the environment contains such a predicate.
// We still error for `i32: Bar<u32>` pending #48214
trait Foo<X,Y>: Bar<X> {
}
trait Bar<X> { }
// We don't always check where clauses for sanity, but in this case
// wfcheck does report an error here:
fn vacuous<A>()
where i32: Foo<u32, A> //~ ERROR the trait bound `i32: Bar<u32>` is not satisfied
{
// ... the original intention was to check that we don't use that
// vacuous where clause (which could never be satisfied) to accept
// the following line and then mess up calls elsewhere.
require::<i32, u32>();
}
fn require<A,B>()
where A: Bar<B>
{
}
fn main() {
require::<i32, u32>();
}
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