Enum diesel::connection::statement_cache::MaybeCached

#[non_exhaustive]
pub enum MaybeCached<'a, T: 'a> {
    CannotCache(T),
    Cached(&'a mut T),
}

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Wraps a possibly cached prepared statement

Essentially a customized version of Cow that does not depend on ToOwned

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

CannotCache(T)

Contains a not cached prepared statement

Cached(&'a mut T)

Contains a reference cached prepared statement

Trait Implementations

impl<'a, T> Deref for MaybeCached<'a, T>

type Target = T

The resulting type after dereferencing.

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

Dereferences the value.

impl<'a, T> DerefMut for MaybeCached<'a, T>

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

Mutably dereferences the value.