Struct BumpPoolGuard

pub struct BumpPoolGuard<'a, A = Global, const MIN_ALIGN: usize = 1, const UP: bool = true>
where
    A: BaseAllocator,
    MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment,
{
    pub pool: &'a BumpPool<A, MIN_ALIGN, UP>,
    /* private fields */
}

Available on crate feature std only.

This is a wrapper around Bump that mutably derefs to a BumpScope and returns its Bump back to the BumpPool on drop.

Fields

pool: &'a BumpPool<A, MIN_ALIGN, UP>

The BumpPool, this BumpPoolGuard was created from.

Methods from Deref<Target = BumpScope<'a, A, MIN_ALIGN, UP>>

pub fn scoped<R>( &mut self, f: impl FnOnce(BumpScope<'_, A, MIN_ALIGN, UP>) -> R, ) -> R

Calls f with a new child scope.

Examples

let mut bump: Bump = Bump::new();

bump.scoped(|bump| {
    bump.alloc_str("Hello world!");
    assert_eq!(bump.stats().allocated(), 12);
});

assert_eq!(bump.stats().allocated(), 0);

pub fn scoped_aligned<const NEW_MIN_ALIGN: usize, R>( &mut self, f: impl FnOnce(BumpScope<'_, A, MIN_ALIGN, UP>) -> R, ) -> R

where MinimumAlignment<NEW_MIN_ALIGN>: SupportedMinimumAlignment,

Calls f with a new child scope of a new minimum alignment.

pub fn scope_guard(&mut self) -> BumpScopeGuard<'_, A, MIN_ALIGN, UP>

Creates a new BumpScopeGuard. This allows for creation of child scopes.

Examples

let mut bump: Bump = Bump::new();

{
    let mut guard = bump.scope_guard();
    let bump = guard.scope();
    bump.alloc_str("Hello world!");
    assert_eq!(bump.stats().allocated(), 12);
}

assert_eq!(bump.stats().allocated(), 0);

pub fn aligned<const NEW_MIN_ALIGN: usize, R>( &mut self, f: impl FnOnce(BumpScope<'_, A, NEW_MIN_ALIGN, UP>) -> R, ) -> R

where MinimumAlignment<NEW_MIN_ALIGN>: SupportedMinimumAlignment,

Calls f with this scope but with a new minimum alignment.

pub fn checkpoint(&self) -> Checkpoint

Creates a checkpoint of the current bump position.

Examples

let checkpoint = bump.checkpoint();

{
    let hello = bump.alloc_str("hello");
    assert_eq!(bump.stats().allocated(), 5);
}

unsafe { bump.reset_to(checkpoint); }
assert_eq!(bump.stats().allocated(), 0);

pub unsafe fn reset_to(&self, checkpoint: Checkpoint)

Resets the bump position to a previously created checkpoint. The memory that has been allocated since then will be reused by future allocations.

Safety

• the checkpoint must have been created by this bump allocator
• the bump allocator must not have been reset since creation of this checkpoint
• there must be no references to allocations made since creation of this checkpoint

pub fn stats(&self) -> Stats<'a, GUARANTEED_ALLOCATED>

Returns a type which provides statistics about the memory usage of the bump allocator.

pub fn allocator(&self) -> &A

Returns a reference to the base allocator.

pub fn as_scope(&self) -> &Self

Returns &self as is. This is useful for macros that support both Bump and BumpScope.

pub fn as_mut_scope(&mut self) -> &mut Self

Returns &mut self as is. This is useful for macros that support both Bump and BumpScope.

pub fn as_aligned_mut<const NEW_MIN_ALIGN: usize>( &mut self, ) -> &mut BumpScope<'a, A, NEW_MIN_ALIGN, UP, GUARANTEED_ALLOCATED>

where MinimumAlignment<NEW_MIN_ALIGN>: SupportedMinimumAlignment,

Mutably borrows BumpScope with a new minimum alignment.

This can not decrease the alignment. Trying to decrease alignment will result in a compile error. You can use aligned or scoped_aligned to decrease the alignment.“

To decrease alignment we need to ensure that we return to our original alignment. That can only be guaranteed by a function taking a closure like the ones mentioned above.

pub fn guaranteed_allocated_ref(&self) -> &BumpScope<'a, A, MIN_ALIGN, UP>

Borrows BumpScope as a guaranteed allocated BumpScope.

Panics

Panics if the allocation fails.

pub fn try_guaranteed_allocated_ref( &self, ) -> Result<&BumpScope<'a, A, MIN_ALIGN, UP>, AllocError>

Borrows BumpScope as a guaranteed allocated BumpScope.

Errors

Errors if the allocation fails.

pub fn guaranteed_allocated_mut( &mut self, ) -> &mut BumpScope<'a, A, MIN_ALIGN, UP>

Mutably borrows BumpScope as a guaranteed allocated BumpScope.

Panics

Panics if the allocation fails.

pub fn try_guaranteed_allocated_mut( &mut self, ) -> Result<&mut BumpScope<'a, A, MIN_ALIGN, UP>, AllocError>

Mutably borrows BumpScope as a guaranteed allocated BumpScope.

Errors

Errors if the allocation fails.

pub fn not_guaranteed_allocated_ref( &self, ) -> &BumpScope<'a, A, MIN_ALIGN, UP, false>

Borrows BumpScope as a not guaranteed allocated BumpScope.

Note that it’s not possible to mutably borrow as a not guaranteed allocated bump allocator. That’s because a user could mem::swap it with an actual unallocated bump allocator which in turn would make &mut self unallocated.

pub fn alloc_zeroed<T>(&self) -> BumpBox<'a, T>

where T: FromZeros,

Available on crate feature zerocopy only.

Allocate a zeroed object.

Panics

Panics if the allocation fails.

Examples

let zero = bump.alloc_zeroed::<i32>();
assert_eq!(*zero, 0);

pub fn alloc_zeroed_slice<T>(&self, len: usize) -> BumpBox<'a, [T]>

where T: FromZeros,

Available on crate feature zerocopy only.

Allocate a zeroed object slice.

Panics

Panics if the allocation fails.

Examples

let zeroes = bump.alloc_zeroed_slice::<i32>(3);
assert_eq!(*zeroes, [0; 3]);

pub fn try_alloc_zeroed<T>(&self) -> Result<BumpBox<'a, T>, AllocError>

where T: FromZeros,

Available on crate feature zerocopy only.

Allocate a zeroed object.

Errors

Errors if the allocation fails.

Examples

let zero = bump.try_alloc_zeroed::<i32>()?;
assert_eq!(*zero, 0);

pub fn try_alloc_zeroed_slice<T>( &self, len: usize, ) -> Result<BumpBox<'a, [T]>, AllocError>

where T: FromZeros,

Available on crate feature zerocopy only.

Allocate a zeroed object slice.

Errors

Errors if the allocation fails.

Examples

let zeroes = bump.try_alloc_zeroed_slice::<i32>(3)?;
assert_eq!(*zeroes, [0; 3]);

pub fn alloc<T>(&self, value: T) -> BumpBox<'a, T>

Allocate an object.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc(123);
assert_eq!(allocated, 123);

pub fn alloc_with<T>(&self, f: impl FnOnce() -> T) -> BumpBox<'a, T>

Pre-allocate space for an object. Once space is allocated f will be called to create the value to be put at that place. In some situations this can help the compiler realize that T can be constructed at the allocated space instead of having to copy it over.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_with(|| 123);
assert_eq!(allocated, 123);

pub fn alloc_default<T: Default>(&self) -> BumpBox<'a, T>

Allocate an object with its default value. This is equivalent to alloc_with(T::default).

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_default::<i32>();
assert_eq!(allocated, 0);

pub fn alloc_slice_copy<T: Copy>(&self, slice: &[T]) -> BumpBox<'a, [T]>

Allocate a slice and Copy elements from an existing slice.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_slice_copy(&[1, 2, 3]);
assert_eq!(allocated, [1, 2, 3]);

pub fn alloc_slice_clone<T: Clone>(&self, slice: &[T]) -> BumpBox<'a, [T]>

Allocate a slice and Clone elements from an existing slice.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_slice_clone(&[String::from("a"), String::from("b")]);
assert_eq!(allocated, [String::from("a"), String::from("b")]);

pub fn alloc_slice_fill<T: Clone>( &self, len: usize, value: T, ) -> BumpBox<'a, [T]>

Allocate a slice and fill it with elements by cloning value.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_slice_fill(3, "ho");
assert_eq!(allocated, ["ho", "ho", "ho"]);

pub fn alloc_slice_fill_with<T>( &self, len: usize, f: impl FnMut() -> T, ) -> BumpBox<'a, [T]>

Allocates a slice by fill it with elements returned by calling a closure repeatedly.

This method uses a closure to create new values. If you’d rather Clone a given value, use alloc_slice_fill. If you want to use the Default trait to generate values, you can pass Default::default as the argument.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_slice_fill_with::<i32>(3, Default::default);
assert_eq!(allocated, [0, 0, 0]);

pub fn alloc_str(&self, src: &str) -> BumpBox<'a, str>

Allocate a str.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_str("Hello world!");
assert_eq!(allocated, "Hello world!");

pub fn alloc_fmt(&self, args: Arguments<'_>) -> BumpBox<'a, str>

Allocate a str from format arguments.

If you have a &mut self you can use alloc_fmt_mut instead for better performance.

Panics

Panics if the allocation fails.

Panics if a formatting trait implementation returned an error.

Examples

let one = 1;
let two = 2;
let string = bump.alloc_fmt(format_args!("{one} + {two} = {}", one + two));

assert_eq!(string, "1 + 2 = 3");

pub fn alloc_fmt_mut(&mut self, args: Arguments<'_>) -> BumpBox<'a, str>

Allocate a str from format arguments.

This function is designed as a performance improvement over alloc_fmt. By taking self as &mut, it can use the entire remaining chunk space as the capacity for its string buffer. As a result, the string buffer rarely needs to grow.

Panics

Panics if the allocation fails.

Panics if a formatting trait implementation returned an error.

Examples

let one = 1;
let two = 2;
let string = bump.alloc_fmt_mut(format_args!("{one} + {two} = {}", one + two));

assert_eq!(string, "1 + 2 = 3");

pub fn alloc_cstr(&self, src: &CStr) -> &'a CStr

Allocate a CStr.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_cstr(c"Hello world!");
assert_eq!(allocated, c"Hello world!");

pub fn alloc_cstr_from_str(&self, src: &str) -> &'a CStr

Allocate a CStr from a str.

If src contains a '\0' then the CStr will stop there.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_cstr_from_str("Hello world!");
assert_eq!(allocated, c"Hello world!");

let allocated = bump.alloc_cstr_from_str("abc\0def");
assert_eq!(allocated, c"abc");

pub fn alloc_cstr_fmt(&self, args: Arguments<'_>) -> &'a CStr

Allocate a CStr from format arguments.

If the string contains a '\0' then the CStr will stop there.

If you have a &mut self you can use alloc_cstr_fmt_mut instead for better performance.

Panics

Panics if the allocation fails.

Panics if a formatting trait implementation returned an error.

Examples

let one = 1;
let two = 2;
let string = bump.alloc_cstr_fmt(format_args!("{one} + {two} = {}", one + two));
assert_eq!(string, c"1 + 2 = 3");

let one = bump.alloc_cstr_fmt(format_args!("{one}\0{two}"));
assert_eq!(one, c"1");

pub fn alloc_cstr_fmt_mut(&mut self, args: Arguments<'_>) -> &'a CStr

Allocate a CStr from format arguments.

If the string contains a '\0' then the CStr will stop there.

This function is designed as a performance improvement over alloc_cstr_fmt. By taking self as &mut, it can use the entire remaining chunk space as the capacity for its string buffer. As a result, the string buffer rarely needs to grow.

Panics

Panics if the allocation fails.

Panics if a formatting trait implementation returned an error.

Examples

let one = 1;
let two = 2;
let string = bump.alloc_cstr_fmt_mut(format_args!("{one} + {two} = {}", one + two));
assert_eq!(string, c"1 + 2 = 3");

let one = bump.alloc_cstr_fmt_mut(format_args!("{one}\0{two}"));
assert_eq!(one, c"1");

pub fn alloc_iter<T>( &self, iter: impl IntoIterator<Item = T>, ) -> BumpBox<'a, [T]>

Allocate elements of an iterator into a slice.

If you have an impl ExactSizeIterator then you can use alloc_iter_exact instead for better performance.

If iter is not an ExactSizeIterator but you have a &mut self you can still get somewhat better performance by using alloc_iter_mut.

Panics

Panics if the allocation fails.

Examples

let slice = bump.alloc_iter([1, 2, 3]);
assert_eq!(slice, [1, 2, 3]);

pub fn alloc_iter_exact<T, I>( &self, iter: impl IntoIterator<Item = T, IntoIter = I>, ) -> BumpBox<'a, [T]>

where I: ExactSizeIterator<Item = T>,

Allocate elements of an ExactSizeIterator into a slice.

Panics

Panics if the allocation fails.

Examples

let slice = bump.alloc_iter_exact([1, 2, 3]);
assert_eq!(slice, [1, 2, 3]);

pub fn alloc_iter_mut<T>( &mut self, iter: impl IntoIterator<Item = T>, ) -> BumpBox<'a, [T]>

Allocate elements of an iterator into a slice.

This function is designed as a performance improvement over alloc_iter. By taking self as &mut, it can use the entire remaining chunk space as the capacity for its vector. As a result, the vector rarely needs to grow.

When bumping downwards, prefer alloc_iter_mut_rev instead.

Panics

Panics if the allocation fails.

Examples

let slice = bump.alloc_iter_mut([1, 2, 3]);
assert_eq!(slice, [1, 2, 3]);

pub fn alloc_iter_mut_rev<T>( &mut self, iter: impl IntoIterator<Item = T>, ) -> BumpBox<'a, [T]>

Allocate elements of an iterator into a slice in reverse order.

Compared to alloc_iter_mut this function is more performant for downwards bumping allocators as the allocation for the vector can be shrunk in place without any ptr::copy.

The reverse is true when upwards allocating. In that case it’s better to use alloc_iter_mut to prevent the ptr::copy.

Panics

Panics if the allocation fails.

Examples

let slice = bump.alloc_iter_mut_rev([1, 2, 3]);
assert_eq!(slice, [3, 2, 1]);

pub fn alloc_uninit<T>(&self) -> BumpBox<'a, MaybeUninit<T>>

Allocate an unitialized object.

You can safely initialize the object with init or unsafely with assume_init.

Panics

Panics if the allocation fails.

Examples

Safely:

let five = bump.alloc_uninit();

let five = five.init(5);

assert_eq!(*five, 5)

Unsafely:

let mut five = bump.alloc_uninit();

let five = unsafe {
    five.write(5);
    five.assume_init()
};

assert_eq!(*five, 5)

pub fn alloc_uninit_slice<T>(&self, len: usize) -> BumpBox<'a, [MaybeUninit<T>]>

Allocate an unitialized object slice.

You can safely initialize the object with init_fill, init_fill_with, init_copy, init_clone or unsafely with assume_init.

Panics

Panics if the allocation fails.

Examples

Safely:

let values = bump.alloc_uninit_slice(3);

let values = values.init_copy(&[1, 2, 3]);

assert_eq!(values, [1, 2, 3])

Unsafely:

let mut values = bump.alloc_uninit_slice(3);

let values = unsafe {
    values[0].write(1);
    values[1].write(2);
    values[2].write(3);

    values.assume_init()
};

assert_eq!(values, [1, 2, 3]);

pub fn alloc_uninit_slice_for<T>( &self, slice: &[T], ) -> BumpBox<'a, [MaybeUninit<T>]>

Allocate an unitialized object slice.

You can safely initialize the object with init_fill, init_fill_with, init_copy, init_clone or unsafely with assume_init.

This is just like alloc_uninit_slice but uses a slice to provide the len. This avoids a check for a valid layout. The elements of slice are irrelevant.

Panics

Panics if the allocation fails.

Examples

let slice = &[1, 2, 3];
let other_slice = bump.alloc_uninit_slice_for(slice);
assert_eq!(other_slice.len(), 3);

pub fn alloc_fixed_vec<T>(&self, capacity: usize) -> FixedBumpVec<'a, T>

Allocate a FixedBumpVec with the given capacity.

Panics

Panics if the allocation fails.

Examples

let mut values = bump.alloc_fixed_vec(3);
values.push(1);
values.push(2);
values.push(3);
assert_eq!(values, [1, 2, 3])

pub fn alloc_fixed_string(&self, capacity: usize) -> FixedBumpString<'a>

Allocate a FixedBumpString with the given capacity in bytes.

Panics

Panics if the allocation fails.

Examples

let mut string = bump.alloc_fixed_string(12);
string.push_str("Hello");
string.push_str(" world!");
assert_eq!(string, "Hello world!");

pub fn alloc_layout(&self, layout: Layout) -> NonNull<u8>

Allocates memory as described by the given Layout.

Panics

Panics if the allocation fails.

pub fn reserve_bytes(&self, additional: usize)

Reserves capacity for at least additional more bytes to be bump allocated. The bump allocator may reserve more space to avoid frequent reallocations. After calling reserve_bytes, self.stats().remaining() will be greater than or equal to additional. Does nothing if the capacity is already sufficient.

Panics

Panics if the allocation fails.

Examples

let bump: Bump = Bump::new();
assert!(bump.stats().capacity() < 4096);

bump.reserve_bytes(4096);
assert!(bump.stats().capacity() >= 4096);

pub fn try_alloc<T>(&self, value: T) -> Result<BumpBox<'a, T>, AllocError>

Allocate an object.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc(123)?;
assert_eq!(allocated, 123);

pub fn try_alloc_with<T>( &self, f: impl FnOnce() -> T, ) -> Result<BumpBox<'a, T>, AllocError>

Pre-allocate space for an object. Once space is allocated f will be called to create the value to be put at that place. In some situations this can help the compiler realize that T can be constructed at the allocated space instead of having to copy it over.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_with(|| 123)?;
assert_eq!(allocated, 123);

pub fn try_alloc_default<T: Default>( &self, ) -> Result<BumpBox<'a, T>, AllocError>

Allocate an object with its default value. This is equivalent to try_alloc_with(T::default).

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_default()?;
assert_eq!(allocated, 0);

pub fn try_alloc_slice_copy<T: Copy>( &self, slice: &[T], ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate a slice and Copy elements from an existing slice.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.alloc_slice_copy(&[1, 2, 3]);
assert_eq!(allocated, [1, 2, 3]);

pub fn try_alloc_slice_clone<T: Clone>( &self, slice: &[T], ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate a slice and Clone elements from an existing slice.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_slice_clone(&[String::from("a"), String::from("b")])?;
assert_eq!(allocated, [String::from("a"), String::from("b")]);

pub fn try_alloc_slice_fill<T: Clone>( &self, len: usize, value: T, ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate a slice and fill it with elements by cloning value.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_slice_fill(3, "ho")?;
assert_eq!(allocated, ["ho", "ho", "ho"]);

pub fn try_alloc_slice_fill_with<T>( &self, len: usize, f: impl FnMut() -> T, ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocates a slice by fill it with elements returned by calling a closure repeatedly.

This method uses a closure to create new values. If you’d rather Clone a given value, use try_alloc_slice_fill. If you want to use the Default trait to generate values, you can pass Default::default as the argument.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_slice_fill_with::<i32>(3, Default::default)?;
assert_eq!(allocated, [0, 0, 0]);

pub fn try_alloc_str(&self, src: &str) -> Result<BumpBox<'a, str>, AllocError>

Allocate a str.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_str("Hello world!")?;
assert_eq!(allocated, "Hello world!");

pub fn try_alloc_fmt( &self, args: Arguments<'_>, ) -> Result<BumpBox<'a, str>, AllocError>

Allocate a str from format arguments.

If you have a &mut self you can use try_alloc_fmt_mut instead for better performance.

Errors

Errors if the allocation fails.

Errors if a formatting trait implementation returned an error.

Examples

let one = 1;
let two = 2;
let string = bump.try_alloc_fmt(format_args!("{one} + {two} = {}", one + two))?;

assert_eq!(string, "1 + 2 = 3");

pub fn try_alloc_fmt_mut( &mut self, args: Arguments<'_>, ) -> Result<BumpBox<'a, str>, AllocError>

Allocate a str from format arguments.

This function is designed as a performance improvement over try_alloc_fmt. By taking self as &mut, it can use the entire remaining chunk space as the capacity for its string buffer. As a result, the string buffer rarely needs to grow.

Errors

Errors if the allocation fails.

Errors if a formatting trait implementation returned an error.

Examples

let one = 1;
let two = 2;
let string = bump.try_alloc_fmt_mut(format_args!("{one} + {two} = {}", one + two))?;

assert_eq!(string, "1 + 2 = 3");

pub fn try_alloc_cstr(&self, src: &CStr) -> Result<&'a CStr, AllocError>

Allocate a CStr.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_cstr(c"Hello world!")?;
assert_eq!(allocated, c"Hello world!");

pub fn try_alloc_cstr_from_str(&self, src: &str) -> Result<&'a CStr, AllocError>

Allocate a CStr from a str.

If src contains a '\0' then the CStr will stop there.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_cstr_from_str("Hello world!")?;
assert_eq!(allocated, c"Hello world!");

let allocated = bump.try_alloc_cstr_from_str("abc\0def")?;
assert_eq!(allocated, c"abc");

pub fn try_alloc_cstr_fmt( &self, args: Arguments<'_>, ) -> Result<&'a CStr, AllocError>

Allocate a CStr from format arguments.

If the string contains a '\0' then the CStr will stop there.

If you have a &mut self you can use try_alloc_cstr_fmt_mut instead for better performance.

Errors

Errors if the allocation fails.

Errors if a formatting trait implementation returned an error.

Examples

let one = 1;
let two = 2;
let string = bump.try_alloc_cstr_fmt(format_args!("{one} + {two} = {}", one + two))?;
assert_eq!(string, c"1 + 2 = 3");

let one = bump.try_alloc_cstr_fmt(format_args!("{one}\0{two}"))?;
assert_eq!(one, c"1");

pub fn try_alloc_cstr_fmt_mut( &mut self, args: Arguments<'_>, ) -> Result<&'a CStr, AllocError>

Allocate a CStr from format arguments.

If the string contains a '\0' then the CStr will stop there.

This function is designed as a performance improvement over try_alloc_cstr_fmt. By taking self as &mut, it can use the entire remaining chunk space as the capacity for its string buffer. As a result, the string buffer rarely needs to grow.

Errors

Errors if the allocation fails.

Errors if a formatting trait implementation returned an error.

Examples

let one = 1;
let two = 2;
let string = bump.try_alloc_cstr_fmt_mut(format_args!("{one} + {two} = {}", one + two))?;
assert_eq!(string, c"1 + 2 = 3");

let one = bump.try_alloc_cstr_fmt_mut(format_args!("{one}\0{two}"))?;
assert_eq!(one, c"1");

pub fn try_alloc_iter<T>( &self, iter: impl IntoIterator<Item = T>, ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate elements of an iterator into a slice.

If you have an impl ExactSizeIterator then you can use try_alloc_iter_exact instead for better performance.

If iter is not an ExactSizeIterator but you have a &mut self you can still get somewhat better performance by using try_alloc_iter_mut.

Errors

Errors if the allocation fails.

Examples

let slice = bump.try_alloc_iter([1, 2, 3])?;
assert_eq!(slice, [1, 2, 3]);

pub fn try_alloc_iter_exact<T, I>( &self, iter: impl IntoIterator<Item = T, IntoIter = I>, ) -> Result<BumpBox<'a, [T]>, AllocError>

where I: ExactSizeIterator<Item = T>,

Allocate elements of an ExactSizeIterator into a slice.

Errors

Errors if the allocation fails.

Examples

let slice = bump.try_alloc_iter_exact([1, 2, 3])?;
assert_eq!(slice, [1, 2, 3]);

pub fn try_alloc_iter_mut<T>( &mut self, iter: impl IntoIterator<Item = T>, ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate elements of an iterator into a slice.

This function is designed as a performance improvement over try_alloc_iter. By taking self as &mut, it can use the entire remaining chunk space as the capacity for its vector. As a result, the vector rarely needs to grow.

When bumping downwards, prefer try_alloc_iter_mut_rev instead.

Errors

Errors if the allocation fails.

Examples

let slice = bump.try_alloc_iter_mut([1, 2, 3])?;
assert_eq!(slice, [1, 2, 3]);

pub fn try_alloc_iter_mut_rev<T>( &mut self, iter: impl IntoIterator<Item = T>, ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate elements of an iterator into a slice in reverse order.

Compared to try_alloc_iter_mut this function is more performant for downwards bumping allocators as the allocation for the vector can be shrunk in place without any ptr::copy.

The reverse is true when upwards allocating. In that case it’s better to use try_alloc_iter_mut to prevent the ptr::copy.

Errors

Errors if the allocation fails.

Examples

let slice = bump.try_alloc_iter_mut_rev([1, 2, 3])?;
assert_eq!(slice, [3, 2, 1]);

pub fn try_alloc_uninit<T>( &self, ) -> Result<BumpBox<'a, MaybeUninit<T>>, AllocError>

Allocate an unitialized object.

You can safely initialize the object with init or unsafely with assume_init.

Errors

Errors if the allocation fails.

Examples

Safely:

let five = bump.try_alloc_uninit()?;

let five = five.init(5);

assert_eq!(*five, 5);

Unsafely:

let mut five = bump.try_alloc_uninit()?;

let five = unsafe {
    five.write(5);
    five.assume_init()
};

assert_eq!(*five, 5);

pub fn try_alloc_uninit_slice<T>( &self, len: usize, ) -> Result<BumpBox<'a, [MaybeUninit<T>]>, AllocError>

Allocate an unitialized object slice.

You can safely initialize the object with init_fill, init_fill_with, init_copy, init_clone or unsafely with assume_init.

Errors

Errors if the allocation fails.

Examples

Safely:

let values = bump.try_alloc_uninit_slice(3)?;

let values = values.init_copy(&[1, 2, 3]);

assert_eq!(values, [1, 2, 3]);

Unsafely:

let mut values = bump.try_alloc_uninit_slice(3)?;

let values = unsafe {
    values[0].write(1);
    values[1].write(2);
    values[2].write(3);

    values.assume_init()
};

assert_eq!(values, [1, 2, 3]);

pub fn try_alloc_uninit_slice_for<T>( &self, slice: &[T], ) -> Result<BumpBox<'a, [MaybeUninit<T>]>, AllocError>

Allocate an unitialized object slice.

You can safely initialize the object with init_fill, init_fill_with, init_copy, init_clone or unsafely with assume_init.

This is just like try_alloc_uninit_slice but uses a slice to provide the len. This avoids a check for a valid layout. The elements of slice are irrelevant.

Errors

Errors if the allocation fails.

Examples

let slice = &[1, 2, 3];
let other_slice = bump.try_alloc_uninit_slice_for(slice)?;
assert_eq!(other_slice.len(), 3);

pub fn try_alloc_fixed_vec<T>( &self, capacity: usize, ) -> Result<FixedBumpVec<'a, T>, AllocError>

Allocate a FixedBumpVec with the given capacity.

Errors

Errors if the allocation fails.

Examples

let mut values = bump.try_alloc_fixed_vec(3)?;
values.push(1);
values.push(2);
values.push(3);
assert_eq!(values, [1, 2, 3]);

pub fn try_alloc_fixed_string( &self, capacity: usize, ) -> Result<FixedBumpString<'a>, AllocError>

Allocate a FixedBumpString with the given capacity in bytes.

Errors

Errors if the allocation fails.

Examples

let mut string = bump.try_alloc_fixed_string(12)?;
string.push_str("Hello");
string.push_str(" world!");
assert_eq!(string, "Hello world!");

pub fn try_alloc_layout( &self, layout: Layout, ) -> Result<NonNull<u8>, AllocError>

Allocates memory as described by the given Layout.

Errors

Errors if the allocation fails.

pub fn try_reserve_bytes(&self, additional: usize) -> Result<(), AllocError>

Reserves capacity for at least additional more bytes to be bump allocated. The bump allocator may reserve more space to avoid frequent reallocations. After calling reserve_bytes, self.stats().remaining() will be greater than or equal to additional. Does nothing if the capacity is already sufficient.

Errors

Errors if the allocation fails.

Examples

let bump: Bump = Bump::try_new()?;
assert!(bump.stats().capacity() < 4096);

bump.try_reserve_bytes(4096)?;
assert!(bump.stats().capacity() >= 4096);

pub fn alloc_try_with<T, E>( &self, f: impl FnOnce() -> Result<T, E>, ) -> Result<BumpBox<'a, T>, E>

Allocates the result of f in the bump allocator, then moves E out of it and deallocates the space it took up.

This can be more performant than allocating T after the fact, as Result<T, E> may be constructed in the bump allocators memory instead of on the stack and then copied over.

There is also alloc_try_with_mut, optimized for a mutable reference.

Panics

Panics if the allocation fails.

Examples

let result = bump.alloc_try_with(|| -> Result<i32, i32> { Ok(123) });
assert_eq!(result.unwrap(), 123);
assert_eq!(bump.stats().allocated(), offset_of!(Result<i32, i32>, Ok.0) + size_of::<i32>());

let result = bump.alloc_try_with(|| -> Result<i32, i32> { Err(123) });
assert_eq!(result.unwrap_err(), 123);
assert_eq!(bump.stats().allocated(), 0);

pub fn alloc_try_with_mut<T, E>( &mut self, f: impl FnOnce() -> Result<T, E>, ) -> Result<BumpBox<'a, T>, E>

Allocates the result of f in the bump allocator, then moves E out of it and deallocates the space it took up.

This can be more performant than allocating T after the fact, as Result<T, E> may be constructed in the bump allocators memory instead of on the stack and then copied over.

This is just like alloc_try_with, but optimized for a mutable reference.

Panics

Panics if the allocation fails.

Examples

let result = bump.alloc_try_with_mut(|| -> Result<i32, i32> { Ok(123) });
assert_eq!(result.unwrap(), 123);
assert_eq!(bump.stats().allocated(), offset_of!(Result<i32, i32>, Ok.0) + size_of::<i32>());

let result = bump.alloc_try_with_mut(|| -> Result<i32, i32> { Err(123) });
assert_eq!(result.unwrap_err(), 123);
assert_eq!(bump.stats().allocated(), 0);

pub fn try_alloc_try_with<T, E>( &self, f: impl FnOnce() -> Result<T, E>, ) -> Result<Result<BumpBox<'a, T>, E>, AllocError>

Allocates the result of f in the bump allocator, then moves E out of it and deallocates the space it took up.

This can be more performant than allocating T after the fact, as Result<T, E> may be constructed in the bump allocators memory instead of on the stack and then copied over.

There is also try_alloc_try_with_mut, optimized for a mutable reference.

Errors

Errors if the allocation fails.

Examples

let result = bump.try_alloc_try_with(|| -> Result<i32, i32> { Ok(123) })?;
assert_eq!(result.unwrap(), 123);
assert_eq!(bump.stats().allocated(), offset_of!(Result<i32, i32>, Ok.0) + size_of::<i32>());

let result = bump.try_alloc_try_with(|| -> Result<i32, i32> { Err(123) })?;
assert_eq!(result.unwrap_err(), 123);
assert_eq!(bump.stats().allocated(), 0);

pub fn try_alloc_try_with_mut<T, E>( &mut self, f: impl FnOnce() -> Result<T, E>, ) -> Result<Result<BumpBox<'a, T>, E>, AllocError>

Allocates the result of f in the bump allocator, then moves E out of it and deallocates the space it took up.

This can be more performant than allocating T after the fact, as Result<T, E> may be constructed in the bump allocators memory instead of on the stack and then copied over.

This is just like try_alloc_try_with, but optimized for a mutable reference.

Errors

Errors if the allocation fails.

Examples

let result = bump.try_alloc_try_with_mut(|| -> Result<i32, i32> { Ok(123) })?;
assert_eq!(result.unwrap(), 123);
assert_eq!(bump.stats().allocated(), offset_of!(Result<i32, i32>, Ok.0) + size_of::<i32>());

let result = bump.try_alloc_try_with_mut(|| -> Result<i32, i32> { Err(123) })?;
assert_eq!(result.unwrap_err(), 123);
assert_eq!(bump.stats().allocated(), 0);

Trait Implementations

impl<'a, A, const MIN_ALIGN: usize, const UP: bool> Debug for BumpPoolGuard<'a, A, MIN_ALIGN, UP>

where A: BaseAllocator + Debug, MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment,

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a, A, const MIN_ALIGN: usize, const UP: bool> Deref for BumpPoolGuard<'a, A, MIN_ALIGN, UP>

where A: BaseAllocator, MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment,

type Target = BumpScope<'a, A, MIN_ALIGN, UP>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<A, const MIN_ALIGN: usize, const UP: bool> DerefMut for BumpPoolGuard<'_, A, MIN_ALIGN, UP>

where A: BaseAllocator, MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment,

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<A, const MIN_ALIGN: usize, const UP: bool> Drop for BumpPoolGuard<'_, A, MIN_ALIGN, UP>

where A: BaseAllocator, MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment,

fn drop(&mut self)

Executes the destructor for this type.