Struct scoped_arena::ScopeProxy

pub struct ScopeProxy<'scope, A: Allocator = Global> { /* fields omitted */ }

Proxy for Scope which allocates memory bound to the scope lifetime and not itself. This allows to create sub-scopes while keeping references to scoped values. Does not frees memory and does not drops values moved on scope when dropped. Parent Scope will do this.

Implementations

impl<'scope, A> ScopeProxy<'scope, A> where
    A: Allocator, 

pub fn alloc(&self, layout: Layout) -> NonNull<[u8]>

Allocates a block of memory. Returns a NonNull<u8> meeting the size and alignment guarantees of layout. The returned block contents should be considered uninitialized.

Returned block will be deallocated when scope is dropped.

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

Attempts to allocate a block of memory. On success, returns a NonNull<u8> meeting the size and alignment guarantees of layout. The returned block contents should be considered uninitialized.

Returned block will be deallocated when scope is dropped.

Errors

Returning Err indicates that memory is exhausted.

pub fn to_scope<T>(&self, value: T) -> &'scope mut T

Move value onto the scope. Returns mutable reference to value with lifetime equal to ’scope lifetime. Value on scope will be dropped when scope is dropped.

This method is as cheap as allocation if value does not needs dropping as reported by core::mem::needs_drop.

pub fn to_scope_with<F, T>(&self, f: F) -> &'scope mut T where
    F: FnOnce() -> T, 

Places value returned from function onto the scope. Returns mutable reference to value with lifetime equal to scope borrow lifetime. Value on scope will be dropped when scope is dropped.

This method is as cheap as allocation if value does not needs dropping as reported by core::mem::needs_drop.

pub fn try_to_scope<T>(
    &self,
    value: T
) -> Result<&'scope mut T, (AllocError, T)>

Tries to move value onto the scope. On success, returns mutable reference to value with lifetime to equal ’scope lifetime. Value on scope will be dropped when scope is dropped.

This method is as cheap as allocation if value does not needs dropping as reported by core::mem::needs_drop.

Errors

Returning Err indicates that memory is exhausted. Returning Err contains original value.

pub fn try_to_scope_with<F, T>(
    &self,
    f: F
) -> Result<&'scope mut T, (AllocError, F)> where
    F: FnOnce() -> T, 

Tries to place value return from function onto the scope. On success, returns mutable reference to value with lifetime equal to scope borrow lifetime. Value on scope will be dropped when scope is dropped.

This method is as cheap as allocation if value does not needs dropping as reported by core::mem::needs_drop.

Errors

Returning Err indicates that memory is exhausted. Returning Err contains original value.

pub fn to_scope_from_iter<T, I>(&self, iter: I) -> &'scope mut [T] where
    I: IntoIterator<Item = T>, 

Move values from iterator onto the scope. Returns mutable reference to slice with lifetime equal to ’scope lifetime. Values on scope will be dropped when scope is dropped.

This method is as cheap as allocation if value does not needs dropping as reported by core::mem::needs_drop.

This method allocates memory to hold iterator’s upper bound number of items. See core::iter::Iterator::size_hint. It will not consume more items. This method will always fail for unbound iterators.

pub fn try_to_scope_from_iter<T, I>(
    &self,
    iter: I
) -> Result<&'scope mut [T], (AllocError, I::IntoIter)> where
    I: IntoIterator<Item = T>, 

Tries to move values from iterator onto the scope. On success, returns mutable reference to slice with lifetime equal to ’scope lifetime. Values on scope will be dropped when scope is dropped.

This method is as cheap as allocation if value does not needs dropping as reported by core::mem::needs_drop.

This method allocates memory to hold iterator’s upper bound number of items. See core::iter::Iterator::size_hint. It will not consume more items. This method will always fail for unbound iterators.

Errors

Returning Err indicates that memory is exhausted. Returning Err contains original iterator.

pub fn total_memory_usage(&self) -> usize

Reports total memory allocated from underlying allocator by associated arena.

pub fn scope_ref(&mut self) -> Scope<'_, &A>

Creates new scope which inherits from the proxy’s scope. This scope becomes locked until returned scope is dropped. Returned scope will use reference to the underlying allocator.

impl<A> ScopeProxy<'_, A> where
    A: Allocator + Clone, 

pub fn scope(&mut self) -> Scope<'_, A>

Creates new scope which inherits from the proxy’s scope. This scope becomes locked until returned scope is dropped. Returned scope will use clone of the underlying allocator.

Trait Implementations

impl<A> Debug for ScopeProxy<'_, A> where
    A: Allocator, 

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

Formats the value using the given formatter.

impl<A> Drop for ScopeProxy<'_, A> where
    A: Allocator, 

fn drop(&mut self)

Executes the destructor for this type.