src/test/ui/borrowck/borrowck-return-variable-on-stack-via-clone.rs - third_party/rust - Git at Google

 // Check that when we clone a `&T` pointer we properly relate the
 // lifetime of the pointer which results to the pointer being cloned.
 // Bugs in method resolution have sometimes broken this connection.
 // Issue #19261.

 fn leak<'a, T>(x: T) -> &'a T {
     (&x).clone() //~ ERROR cannot return value referencing function parameter `x`
 }

 fn main() { }
	// Check that when we clone a `&T` pointer we properly relate the
	// lifetime of the pointer which results to the pointer being cloned.
	// Bugs in method resolution have sometimes broken this connection.
	// Issue #19261.

	fn leak<'a, T>(x: T) -> &'a T {
	(&x).clone() //~ ERROR cannot return value referencing function parameter `x`
	}

	fn main() { }