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use core::marker::PhantomData;
use crate::{Identifier, Token};
#[macro_export]
macro_rules! scope {
($scope:ident) => {
let $scope = unsafe { $crate::scoped::Scoped::new_unchecked() };
let scope = ();
let assert_unique_scope = $crate::scoped::export::AssertUniqueScope::new(&$scope);
assert_unique_scope.bind(&scope);
};
}
#[doc(hidden)]
pub mod export {
use core::marker::PhantomData;
pub struct AssertUniqueScope<'a>(PhantomData<super::Invariant<'a>>);
impl Drop for AssertUniqueScope<'_> {
#[inline(always)]
fn drop(&mut self) {}
}
impl<'a> AssertUniqueScope<'a> {
#[inline(always)]
pub fn new(_: &super::Scoped<'a>) -> Self { Self(PhantomData) }
#[inline(always)]
pub fn bind(&self, _: &'a ()) {}
}
}
struct Invariant<'a>(fn() -> *mut &'a ());
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Scoped<'a> {
invariant: PhantomData<Invariant<'a>>,
}
#[derive(Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct ScopedToken<'a> {
invariant: PhantomData<Invariant<'a>>,
}
impl<'scope> Scoped<'scope> {
#[doc(hidden)]
#[inline(always)]
pub unsafe fn new_unchecked() -> Self { Self { invariant: PhantomData } }
#[inline]
pub fn with<R, F: FnOnce(Scoped<'_>) -> R>(f: F) -> R { f(unsafe { Self::new_unchecked() }) }
pub const fn token(&self) -> ScopedToken<'scope> { ScopedToken::new() }
}
impl ScopedToken<'_> {
#[inline]
pub const fn new() -> Self { Self { invariant: PhantomData } }
}
impl crate::Init for ScopedToken<'_> {
const INIT: Self = Self { invariant: PhantomData };
}
impl crate::Trivial for ScopedToken<'_> {}
unsafe impl Token for ScopedToken<'_> {}
unsafe impl crate::OneShotIdentifier for Scoped<'_> {}
unsafe impl<'a> Identifier for Scoped<'a> {
type Token = ScopedToken<'a>;
#[inline]
fn owns_token(&self, _: &Self::Token) -> bool { true }
#[inline]
fn token(&self) -> Self::Token { ScopedToken::new() }
}
use core::fmt;
impl fmt::Debug for Scoped<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("Scoped").finish() }
}
impl fmt::Debug for ScopedToken<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("ScopedToken").finish() }
}