rust/tests/ui/consts/const-ref-to-static-linux-vtable.rs

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//@check-pass
//! This is the reduced version of the "Linux kernel vtable" use-case.
#![feature(const_mut_refs, const_refs_to_static)]
use std::ptr::addr_of_mut;
#[repr(C)]
struct ThisModule(i32);
trait Module {
const THIS_MODULE_PTR: *mut ThisModule;
}
struct MyModule;
// Generated by a macro.
extern "C" {
static mut THIS_MODULE: ThisModule;
}
// Generated by a macro.
impl Module for MyModule {
const THIS_MODULE_PTR: *mut ThisModule = unsafe { addr_of_mut!(THIS_MODULE) };
}
struct Vtable {
module: *mut ThisModule,
foo_fn: fn(*mut ()) -> i32,
}
trait Foo {
type Mod: Module;
fn foo(&mut self) -> i32;
}
fn generate_vtable<T: Foo>() -> &'static Vtable {
&Vtable {
module: T::Mod::THIS_MODULE_PTR,
foo_fn: |ptr| unsafe { &mut *ptr.cast::<T>() }.foo(),
}
}
fn main() {}