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/// Custom code to free a handle.
///
/// This is similar to the [`Drop`] trait, and may be used to implement [`Drop`], but allows handles
/// to be dropped depending on context.
pub trait Free {
/// Calls the handle's free function.
///
/// # Safety
/// The handle must be owned by the caller and safe to free.
unsafe fn free(&mut self);
}
/// A wrapper to provide ownership for handles to automatically drop via the handle's [`Free`] trait.
#[repr(transparent)]
#[derive(PartialEq, Eq, Default, Debug)]
pub struct Owned<T: Free>(T);
impl<T: Free> Owned<T> {
/// Takes ownership of the handle.
///
/// # Safety
///
/// The handle must be owned by the caller and safe to free.
pub unsafe fn new(x: T) -> Self {
Self(x)
}
}
impl<T: Free> Drop for Owned<T> {
fn drop(&mut self) {
unsafe { self.0.free() };
}
}
impl<T: Free> core::ops::Deref for Owned<T> {
type Target = T;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl<T: Free> core::ops::DerefMut for Owned<T> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.0
}
}