Struct lazy_init::LazyTransform
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[src]
pub struct LazyTransform<T, U> { /* fields omitted */ }LazyTransform<T, U> is a synchronized holder type, that holds a value of
type T until it is lazily converted into a value of type U.
Methods
impl<T, U> LazyTransform<T, U>[src]
fn new(t: T) -> LazyTransform<T, U>
Construct a new, untransformed LazyTransform<T, U> with an argument of
type T.
fn get_or_create<'a, F>(&'a self, f: F) -> &'a U where F: FnOnce(T) -> U
Get a reference to the transformed value, invoking f to transform it
if the LazyTransform<T, U> has yet to be transformed. It is
guaranteed that if multiple calls to get_or_create race, only one
will invoke its closure, and every call will receive a reference to the
newly transformed value.
The closure can only ever be called once, so think carefully about what transformation you want to apply!
fn get<'a>(&'a self) -> Option<&'a U>
Get a reference to the transformed value, returning Some(&U) if the
LazyTransform<T, U> has been transformed or None if it has not. It
is guaranteed that if a reference is returned it is to the transformed
value inside the the LazyTransform<T>.