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/// Temporary fork of some stuff in `core` that's doesn't have a `const fn` API
pub mod mem {
#[cfg(not(feature = "const-fn"))]
pub use core::mem;
pub use core::mem::{replace, zeroed, ManuallyDrop};
// See RFC 1892
#[cfg(feature = "const-fn")]
pub union MaybeUninit<T> {
uninit: (),
value: ManuallyDrop<T>,
}
// workaround to get this to compile on stable ("unions with non-`Copy` fields are unstable")
#[cfg(not(feature = "const-fn"))]
pub struct MaybeUninit<T> {
value: ManuallyDrop<T>,
}
impl<T> MaybeUninit<T> {
#[cfg(feature = "const-fn")]
pub const unsafe fn uninitialized() -> Self {
MaybeUninit { uninit: () }
}
#[cfg(not(feature = "const-fn"))]
pub unsafe fn uninitialized() -> Self {
mem::uninitialized()
}
/// Get a reference to the contained value.
///
/// # Unsafety
///
/// It is up to the caller to guarantee that the the `MaybeUninit` really is in an
/// initialized state, otherwise this will immediately cause undefined behavior.
pub unsafe fn get_ref(&self) -> &T {
&*self.value
}
/// Get a mutable reference to the contained value.
///
/// # Unsafety
///
/// It is up to the caller to guarantee that the the `MaybeUninit` really is in an
/// initialized state, otherwise this will immediately cause undefined behavior.
pub unsafe fn get_mut(&mut self) -> &mut T {
&mut *self.value
}
}
}