#[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.
Expand description

Wraps a possibly cached prepared statement

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

Variants (Non-exhaustive)§

This enum is marked as 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.
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CannotCache(T)

Contains a not cached prepared statement

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Cached(&'a mut T)

Contains a reference cached prepared statement

Trait Implementations§

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

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type Target = T

The resulting type after dereferencing.
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fn deref(&self) -> &Self::Target

Dereferences the value.
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impl<'a, T> DerefMut for MaybeCached<'a, T>

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

Mutably dereferences the value.

Auto Trait Implementations§

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impl<'a, T> RefUnwindSafe for MaybeCached<'a, T>where T: RefUnwindSafe,

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impl<'a, T> Send for MaybeCached<'a, T>where T: Send,

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impl<'a, T> Sync for MaybeCached<'a, T>where T: Sync,

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impl<'a, T> Unpin for MaybeCached<'a, T>where T: Unpin,

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impl<'a, T> !UnwindSafe for MaybeCached<'a, T>

Blanket Implementations§

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> IntoSql for T

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fn into_sql<T>(self) -> AsExprOf<Self, T>where Self: AsExpression<T> + Sized, T: SqlType + TypedExpressionType,

Convert self to an expression for Diesel’s query builder. Read more
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fn as_sql<'a, T>(&'a self) -> AsExprOf<&'a Self, T>where &'a Self: AsExpression<T>, T: SqlType + TypedExpressionType,

Convert &self to an expression for Diesel’s query builder. Read more
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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<V, T> VZip<V> for Twhere V: MultiLane<T>,

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fn vzip(self) -> V

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impl<T> Formattable for Twhere T: Deref, <T as Deref>::Target: Formattable,

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impl<T> Parsable for Twhere T: Deref, <T as Deref>::Target: Parsable,