Struct lazycell::LazyCell

pub struct LazyCell<T> { /* fields omitted */ }

A lazily filled Cell, with frozen contents.

Methods

impl<T> LazyCell<T>

fn new() -> LazyCell<T>

Creates a new, empty, LazyCell.

fn fill(&self, value: T) -> Result<(), T>

Put a value into this cell.

This function will return Err(value) is the cell is already full.

fn filled(&self) -> bool

Test whether this cell has been previously filled.

fn borrow(&self) -> Option<&T>

Borrows the contents of this lazy cell for the duration of the cell itself.

This function will return Some if the cell has been previously initialized, and None if it has not yet been initialized.

fn borrow_mut(&mut self) -> Option<&mut T>

Borrows the contents of this lazy cell mutably for the duration of the cell itself.

This function will return Some if the cell has been previously initialized, and None if it has not yet been initialized.

fn borrow_with<F: FnOnce() -> T>(&self, f: F) -> &T

Borrows the contents of this lazy cell for the duration of the cell itself.

If the cell has not yet been filled, the cell is first filled using the function provided.

Panics

Panics if the cell becomes filled as a side effect of f.

fn try_borrow_with<E, F>(&self, f: F) -> Result<&T, E> where
    F: FnOnce() -> Result<T, E>, 

Same as borrow_with, but allows the initializing function to fail.

Panics

Panics if the cell becomes filled as a side effect of f.

fn into_inner(self) -> Option<T>

Consumes this LazyCell, returning the underlying value.

impl<T: Copy> LazyCell<T>

fn get(&self) -> Option<T>

Returns a copy of the contents of the lazy cell.

This function will return Some if the cell has been previously initialized, and None if it has not yet been initialized.

Trait Implementations

impl<T: Debug> Debug for LazyCell<T>

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<T: Default> Default for LazyCell<T>

fn default() -> LazyCell<T>

Returns the "default value" for a type.