From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 21:33:14 +0200 Subject: Adding upstream version 115.7.0esr. Signed-off-by: Daniel Baumann --- third_party/rust/hashbrown/src/scopeguard.rs | 74 ++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 third_party/rust/hashbrown/src/scopeguard.rs (limited to 'third_party/rust/hashbrown/src/scopeguard.rs') diff --git a/third_party/rust/hashbrown/src/scopeguard.rs b/third_party/rust/hashbrown/src/scopeguard.rs new file mode 100644 index 0000000000..f85e6ab0ed --- /dev/null +++ b/third_party/rust/hashbrown/src/scopeguard.rs @@ -0,0 +1,74 @@ +// Extracted from the scopeguard crate +use core::{ + mem, + ops::{Deref, DerefMut}, + ptr, +}; + +pub struct ScopeGuard +where + F: FnMut(&mut T), +{ + dropfn: F, + value: T, +} + +#[inline] +pub fn guard(value: T, dropfn: F) -> ScopeGuard +where + F: FnMut(&mut T), +{ + ScopeGuard { dropfn, value } +} + +impl ScopeGuard +where + F: FnMut(&mut T), +{ + #[inline] + pub fn into_inner(guard: Self) -> T { + // Cannot move out of Drop-implementing types, so + // ptr::read the value and forget the guard. + unsafe { + let value = ptr::read(&guard.value); + // read the closure so that it is dropped, and assign it to a local + // variable to ensure that it is only dropped after the guard has + // been forgotten. (In case the Drop impl of the closure, or that + // of any consumed captured variable, panics). + let _dropfn = ptr::read(&guard.dropfn); + mem::forget(guard); + value + } + } +} + +impl Deref for ScopeGuard +where + F: FnMut(&mut T), +{ + type Target = T; + #[inline] + fn deref(&self) -> &T { + &self.value + } +} + +impl DerefMut for ScopeGuard +where + F: FnMut(&mut T), +{ + #[inline] + fn deref_mut(&mut self) -> &mut T { + &mut self.value + } +} + +impl Drop for ScopeGuard +where + F: FnMut(&mut T), +{ + #[inline] + fn drop(&mut self) { + (self.dropfn)(&mut self.value); + } +} -- cgit v1.2.3