| #![allow(dead_code)] |
| |
| use core::ffi::c_void; |
| use core::mem::{align_of, size_of}; |
| use core::ptr::{null, null_mut, NonNull}; |
| |
| /// Convert a `&T` into a `*const T` without using an `as`. |
| #[inline] |
| pub(crate) const fn as_ptr<T>(t: &T) -> *const T { |
| t |
| } |
| |
| /// Convert a `&mut T` into a `*mut T` without using an `as`. |
| #[inline] |
| pub(crate) fn as_mut_ptr<T>(t: &mut T) -> *mut T { |
| t |
| } |
| |
| /// Convert an `Option<&T>` into a possibly-null `*const T`. |
| #[inline] |
| pub(crate) const fn option_as_ptr<T>(t: Option<&T>) -> *const T { |
| match t { |
| Some(t) => t, |
| None => null(), |
| } |
| } |
| |
| /// Convert an `Option<&mut T>` into a possibly-null `*mut T`. |
| #[inline] |
| pub(crate) fn option_as_mut_ptr<T>(t: Option<&mut T>) -> *mut T { |
| match t { |
| Some(t) => t, |
| None => null_mut(), |
| } |
| } |
| |
| /// Convert a `*mut c_void` to a `*mut T`, checking that it is not null, |
| /// misaligned, or pointing to a region of memory that wraps around the address |
| /// space. |
| pub(crate) fn check_raw_pointer<T>(value: *mut c_void) -> Option<NonNull<T>> { |
| if (value as usize).checked_add(size_of::<T>()).is_none() |
| || (value as usize) % align_of::<T>() != 0 |
| { |
| return None; |
| } |
| |
| NonNull::new(value.cast()) |
| } |