Static DANGLING_POINTERS_FROM_LOCALS 

pub static DANGLING_POINTERS_FROM_LOCALS: &Lint

The dangling_pointers_from_locals lint detects getting a pointer to data of a local that will be dropped at the end of the function.

Example

fn f() -> *const u8 {
    let x = 0;
    &x // returns a dangling ptr to `x`
}

{{produces}}

Explanation

Returning a pointer from a local value will not prolong its lifetime, which means that the value can be dropped and the allocation freed while the pointer still exists, making the pointer dangling. This is not an error (as far as the type system is concerned) but probably is not what the user intended either.

If you need stronger guarantees, consider using references instead, as they are statically verified by the borrow-checker to never dangle.