mirror of https://github.com/rust-lang/rust
116 lines
2.3 KiB
Rust
116 lines
2.3 KiB
Rust
// FIXME run-pass
|
|
//@ known-bug: #110395
|
|
//@ revisions: stock precise
|
|
#![feature(const_trait_impl)]
|
|
#![feature(never_type)]
|
|
#![cfg_attr(precise, feature(const_precise_live_drops))]
|
|
|
|
use std::marker::Destruct;
|
|
|
|
struct S<'a>(&'a mut u8);
|
|
|
|
impl<'a> const Drop for S<'a> {
|
|
fn drop(&mut self) {
|
|
*self.0 += 1;
|
|
}
|
|
}
|
|
|
|
const fn a<T: ~const Destruct>(_: T) {}
|
|
//FIXME ~^ ERROR destructor of
|
|
|
|
const fn b() -> u8 {
|
|
let mut c = 0;
|
|
let _ = S(&mut c);
|
|
//FIXME ~^ ERROR destructor of
|
|
a(S(&mut c));
|
|
c
|
|
}
|
|
|
|
const C: u8 = b();
|
|
|
|
macro_rules! implements_const_drop {
|
|
($($exp:expr),*$(,)?) => {
|
|
$(
|
|
const _: () = a($exp);
|
|
)*
|
|
}
|
|
}
|
|
|
|
#[allow(dead_code)]
|
|
mod t {
|
|
pub struct Foo;
|
|
pub enum Bar { A }
|
|
pub fn foo() {}
|
|
pub struct ConstDrop;
|
|
|
|
impl const Drop for ConstDrop {
|
|
fn drop(&mut self) {}
|
|
}
|
|
|
|
pub struct HasConstDrop(pub ConstDrop);
|
|
pub struct TrivialFields(pub u8, pub i8, pub usize, pub isize);
|
|
|
|
#[const_trait]
|
|
pub trait SomeTrait {
|
|
fn foo();
|
|
}
|
|
impl const SomeTrait for () {
|
|
fn foo() {}
|
|
}
|
|
// non-const impl
|
|
impl SomeTrait for i32 {
|
|
fn foo() {}
|
|
}
|
|
|
|
pub struct ConstDropWithBound<T: const SomeTrait>(pub core::marker::PhantomData<T>);
|
|
|
|
impl<T: ~const SomeTrait> const Drop for ConstDropWithBound<T> {
|
|
fn drop(&mut self) {
|
|
T::foo();
|
|
}
|
|
}
|
|
|
|
pub struct ConstDropWithNonconstBound<T: SomeTrait>(pub core::marker::PhantomData<T>);
|
|
|
|
impl<T: SomeTrait> const Drop for ConstDropWithNonconstBound<T> {
|
|
fn drop(&mut self) {
|
|
// Note: we DON'T use the `T: SomeTrait` bound
|
|
}
|
|
}
|
|
}
|
|
|
|
use t::*;
|
|
|
|
implements_const_drop! {
|
|
1u8,
|
|
2,
|
|
3.0,
|
|
Foo,
|
|
Bar::A,
|
|
foo,
|
|
ConstDrop,
|
|
HasConstDrop(ConstDrop),
|
|
TrivialFields(1, 2, 3, 4),
|
|
&1,
|
|
&1 as *const i32,
|
|
ConstDropWithBound::<()>,
|
|
ConstDropWithNonconstBound::<i32>,
|
|
Result::<i32, !>::Ok(1),
|
|
}
|
|
|
|
fn main() {
|
|
struct HasDropGlue(#[allow(dead_code)] Box<u8>);
|
|
struct HasDropImpl;
|
|
impl Drop for HasDropImpl {
|
|
fn drop(&mut self) {
|
|
println!("not trivial drop");
|
|
}
|
|
}
|
|
|
|
// These types should pass because ~const in a non-const context should have no effect.
|
|
a(HasDropGlue(Box::new(0)));
|
|
a(HasDropImpl);
|
|
|
|
assert_eq!(C, 2);
|
|
}
|