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Diffstat (limited to '')
-rw-r--r-- | src/test/ui/regions/regions-implied-bounds-projection-gap-1.rs | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/test/ui/regions/regions-implied-bounds-projection-gap-1.rs b/src/test/ui/regions/regions-implied-bounds-projection-gap-1.rs new file mode 100644 index 000000000..38fc9c462 --- /dev/null +++ b/src/test/ui/regions/regions-implied-bounds-projection-gap-1.rs @@ -0,0 +1,30 @@ +// Illustrates the "projection gap": in this test, even though we know +// that `T::Foo: 'x`, that does not tell us that `T: 'x`, because +// there might be other ways for the caller of `func` to show that +// `T::Foo: 'x` holds (e.g., where-clause). + +trait Trait1<'x> { + type Foo; +} + +// calling this fn should trigger a check that the type argument +// supplied is well-formed. +fn wf<T>() { } + +fn func<'x, T:Trait1<'x>>(t: &'x T::Foo) +{ + wf::<&'x T>(); + //~^ ERROR the parameter type `T` may not live long enough +} + +fn caller2<'x, T:Trait1<'x>>(t: &'x T) +{ + wf::<&'x T::Foo>(); // OK +} + +fn caller3<'x, T:Trait1<'x>>(t: &'x T::Foo) +{ + wf::<&'x T::Foo>(); // OK +} + +fn main() { } |