tests/ui/cast/ptr-to-ptr-different-regions.rs

// https://github.com/rust-lang/rust/issues/113257

#![deny(trivial_casts)] // The casts here are not trivial.

struct Foo<'a> {
    a: &'a (),
}

fn extend_lifetime_very_very_safely<'a>(v: *const Foo<'a>) -> *const Foo<'static> {
    // This should pass because raw pointer casts can do anything they want when
    // VTables are not involved
    v as *const Foo<'static>
}

trait Trait {}

// We want to forbid this as extending lifetimes on object types may allow for
// uncallable VTable methods to become accessible.
fn assert_static<'a>(ptr: *mut (dyn Trait + 'a)) -> *mut (dyn Trait + 'static) {
    ptr as _
    //~^ ERROR: lifetime may not live long enough
}

fn main() {
    let unit = ();
    let foo = Foo { a: &unit };
    let _long: *const Foo<'static> = extend_lifetime_very_very_safely(&foo);
}