linux-support 0.0.25

// This file is part of linux-support. It is subject to the license terms in the COPYRIGHT file found in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/linux-support/master/COPYRIGHT. No part of linux-support, including this file, may be copied, modified, propagated, or distributed except according to the terms contained in the COPYRIGHT file.
// Copyright © 2020 The developers of linux-support. See the COPYRIGHT file in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/linux-support/master/COPYRIGHT.


/// A pointer.
#[repr(C, align(8))]
#[derive(Default, Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct AlignedU64(pub u64);

impl<'t, T: Sized> From<&'t T> for AlignedU64
{
	#[inline(always)]
	fn from(value: &'t T) -> Self
	{
		Self::from(value as *const T)
	}
}

impl<T: Sized> Into<*const T> for AlignedU64
{
	#[inline(always)]
	fn into(self) -> *const T
	{
		self.0 as usize as *const T
	}
}

impl<T: Sized> Into<*mut T> for AlignedU64
{
	#[inline(always)]
	fn into(self) -> *mut T
	{
		self.0 as usize as *mut T
	}
}

impl<'t, T: Sized> From<&'t mut T> for AlignedU64
{
	#[inline(always)]
	fn from(value: &'t mut T) -> Self
	{
		Self::from(value as *mut T)
	}
}

impl<T: Sized> From<*const T> for AlignedU64
{
	#[inline(always)]
	fn from(value: *const T) -> Self
	{
		let value = value as usize;
		debug_assert_eq!(value % size_of::<u64>(), 0, "Not 8-byte aligned");
		Self(value as u64)
	}
}

impl<T: Sized> From<*mut T> for AlignedU64
{
	#[inline(always)]
	fn from(value: *mut T) -> Self
	{
		let value = value as usize;
		debug_assert_eq!(value % size_of::<u64>(), 0, "Not 8-byte aligned");
		Self(value as u64)
	}
}

impl<T: Sized> From<NonNull<T>> for AlignedU64
{
	#[inline(always)]
	fn from(value: NonNull<T>) -> Self
	{
		Self::from(value.as_ptr())
	}
}

impl<'a, T: Sized> From<&'a [T]> for AlignedU64
{
	#[inline(always)]
	fn from(value: &'a [T]) -> Self
	{
		Self::from(value.as_ptr())
	}
}

impl<'a, T: Sized> From<&'a mut [T]> for AlignedU64
{
	#[inline(always)]
	fn from(value: &'a mut [T]) -> Self
	{
		Self::from(value.as_mut_ptr())
	}
}

impl Display for AlignedU64
{
	#[inline(always)]
	fn fmt(&self, f: &mut Formatter) -> fmt::Result
	{
		Display::fmt(&self.0, f)
	}
}

impl AlignedU64
{
	pub(crate) const Null: Self = Self(0);
	
	/// To slice.
	#[inline(always)]
	pub fn to_slice<'a, T: Sized>(self, size: u32) -> Option<&'a [T]>
	{
		let pointer: *const T = self.into();
		if pointer.is_null()
		{
			None
		}
		else
		{
			Some(unsafe { from_raw_parts(pointer, size as usize) })
		}
	}
	
	/// To an array.
	#[inline(always)]
	pub fn to_array_of_elements_whose_size_varies_by_linux_version(self, size: u32, element_size: u32) -> Option<ArrayOfElementsWhoseSizeVariesByLinuxVersion>
	{
		let pointer: *mut u8 = self.into();
		if pointer.is_null()
		{
			None
		}
		else
		{
			Some
			(
				ArrayOfElementsWhoseSizeVariesByLinuxVersion
				{
					pointer: new_non_null(pointer),
					number_of_elements: size as usize,
					element_size_for_this_version_of_linux: element_size as usize
				}
			)
		}
	}
}