Struct rustc_arena::DroplessArena
source · pub struct DroplessArena {
pub(crate) start: Cell<*mut u8>,
pub(crate) end: Cell<*mut u8>,
pub(crate) chunks: RefCell<Vec<ArenaChunk>>,
}
Expand description
An arena that can hold objects of multiple different types that impl Copy
and/or satisfy !mem::needs_drop
.
Fields§
§start: Cell<*mut u8>
A pointer to the start of the free space.
end: Cell<*mut u8>
A pointer to the end of free space.
The allocation proceeds downwards from the end of the chunk towards the start. (This is slightly simpler and faster than allocating upwards, see https://fitzgeraldnick.com/2019/11/01/always-bump-downwards.html.) When this pointer crosses the start pointer, a new chunk is allocated.
This is kept aligned to DROPLESS_ALIGNMENT.
chunks: RefCell<Vec<ArenaChunk>>
A vector of arena chunks.
Implementations§
source§impl DroplessArena
impl DroplessArena
pub(crate) fn grow(&self, layout: Layout)
pub fn alloc_raw(&self, layout: Layout) -> *mut u8
pub fn alloc<T>(&self, object: T) -> &mut T
sourcepub fn alloc_slice<T>(&self, slice: &[T]) -> &mut [T]where
T: Copy,
pub fn alloc_slice<T>(&self, slice: &[T]) -> &mut [T]where T: Copy,
Allocates a slice of objects that are copied into the DroplessArena
, returning a mutable
reference to it. Will panic if passed a zero-sized type.
Panics:
- Zero-sized types
- Zero-length slices
sourcepub(crate) unsafe fn write_from_iter<T, I: Iterator<Item = T>>(
&self,
iter: I,
len: usize,
mem: *mut T
) -> &mut [T]
pub(crate) unsafe fn write_from_iter<T, I: Iterator<Item = T>>( &self, iter: I, len: usize, mem: *mut T ) -> &mut [T]
Safety
The caller must ensure that mem
is valid for writes up to
size_of::<T>() * len
.
pub fn alloc_from_iter<T, I: IntoIterator<Item = T>>(&self, iter: I) -> &mut [T]
Trait Implementations§
source§impl Default for DroplessArena
impl Default for DroplessArena
source§fn default() -> DroplessArena
fn default() -> DroplessArena
impl Send for DroplessArena
Auto Trait Implementations§
impl !RefUnwindSafe for DroplessArena
impl !Sync for DroplessArena
impl Unpin for DroplessArena
impl UnwindSafe for DroplessArena
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Layout§
Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...)
attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.
Size: 48 bytes