diff options
Diffstat (limited to 'third_party/rust/anyhow/src/ptr.rs')
-rw-r--r-- | third_party/rust/anyhow/src/ptr.rs | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/third_party/rust/anyhow/src/ptr.rs b/third_party/rust/anyhow/src/ptr.rs new file mode 100644 index 0000000000..c7fe488b6f --- /dev/null +++ b/third_party/rust/anyhow/src/ptr.rs @@ -0,0 +1,199 @@ +use alloc::boxed::Box; +use core::marker::PhantomData; +use core::ptr::NonNull; + +#[repr(transparent)] +pub struct Own<T> +where + T: ?Sized, +{ + pub ptr: NonNull<T>, +} + +unsafe impl<T> Send for Own<T> where T: ?Sized {} + +unsafe impl<T> Sync for Own<T> where T: ?Sized {} + +impl<T> Copy for Own<T> where T: ?Sized {} + +impl<T> Clone for Own<T> +where + T: ?Sized, +{ + fn clone(&self) -> Self { + *self + } +} + +impl<T> Own<T> +where + T: ?Sized, +{ + pub fn new(ptr: Box<T>) -> Self { + Own { + ptr: unsafe { NonNull::new_unchecked(Box::into_raw(ptr)) }, + } + } + + pub fn cast<U: CastTo>(self) -> Own<U::Target> { + Own { + ptr: self.ptr.cast(), + } + } + + pub unsafe fn boxed(self) -> Box<T> { + Box::from_raw(self.ptr.as_ptr()) + } + + pub fn by_ref(&self) -> Ref<T> { + Ref { + ptr: self.ptr, + lifetime: PhantomData, + } + } + + pub fn by_mut(&mut self) -> Mut<T> { + Mut { + ptr: self.ptr, + lifetime: PhantomData, + } + } +} + +#[repr(transparent)] +pub struct Ref<'a, T> +where + T: ?Sized, +{ + pub ptr: NonNull<T>, + lifetime: PhantomData<&'a T>, +} + +impl<'a, T> Copy for Ref<'a, T> where T: ?Sized {} + +impl<'a, T> Clone for Ref<'a, T> +where + T: ?Sized, +{ + fn clone(&self) -> Self { + *self + } +} + +impl<'a, T> Ref<'a, T> +where + T: ?Sized, +{ + pub fn new(ptr: &'a T) -> Self { + Ref { + ptr: NonNull::from(ptr), + lifetime: PhantomData, + } + } + + #[cfg(not(anyhow_no_ptr_addr_of))] + pub fn from_raw(ptr: NonNull<T>) -> Self { + Ref { + ptr, + lifetime: PhantomData, + } + } + + pub fn cast<U: CastTo>(self) -> Ref<'a, U::Target> { + Ref { + ptr: self.ptr.cast(), + lifetime: PhantomData, + } + } + + #[cfg(not(anyhow_no_ptr_addr_of))] + pub fn by_mut(self) -> Mut<'a, T> { + Mut { + ptr: self.ptr, + lifetime: PhantomData, + } + } + + #[cfg(not(anyhow_no_ptr_addr_of))] + pub fn as_ptr(self) -> *const T { + self.ptr.as_ptr() as *const T + } + + pub unsafe fn deref(self) -> &'a T { + &*self.ptr.as_ptr() + } +} + +#[repr(transparent)] +pub struct Mut<'a, T> +where + T: ?Sized, +{ + pub ptr: NonNull<T>, + lifetime: PhantomData<&'a mut T>, +} + +impl<'a, T> Copy for Mut<'a, T> where T: ?Sized {} + +impl<'a, T> Clone for Mut<'a, T> +where + T: ?Sized, +{ + fn clone(&self) -> Self { + *self + } +} + +impl<'a, T> Mut<'a, T> +where + T: ?Sized, +{ + #[cfg(anyhow_no_ptr_addr_of)] + pub fn new(ptr: &'a mut T) -> Self { + Mut { + ptr: NonNull::from(ptr), + lifetime: PhantomData, + } + } + + pub fn cast<U: CastTo>(self) -> Mut<'a, U::Target> { + Mut { + ptr: self.ptr.cast(), + lifetime: PhantomData, + } + } + + #[cfg(not(anyhow_no_ptr_addr_of))] + pub fn by_ref(self) -> Ref<'a, T> { + Ref { + ptr: self.ptr, + lifetime: PhantomData, + } + } + + pub fn extend<'b>(self) -> Mut<'b, T> { + Mut { + ptr: self.ptr, + lifetime: PhantomData, + } + } + + pub unsafe fn deref_mut(self) -> &'a mut T { + &mut *self.ptr.as_ptr() + } +} + +impl<'a, T> Mut<'a, T> { + pub unsafe fn read(self) -> T { + self.ptr.as_ptr().read() + } +} + +// Force turbofish on all calls of `.cast::<U>()`. +pub trait CastTo { + type Target; +} + +impl<T> CastTo for T { + type Target = T; +} |