Struct diesel::r2d2::Extensions

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pub struct Extensions(/* private fields */);
Available on crate feature r2d2 only.
Expand description

A “type map” used to associate data with pooled connections.

Extensions is a data structure mapping types to a value of that type. This can be used to, for example, cache prepared statements along side their connection.

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impl Extensions

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pub fn new() -> Extensions

Returns a new, empty Extensions.

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pub fn insert<T>(&mut self, value: T) -> Option<T>
where T: 'static + Sync + Send,

Inserts a new value into the map.

Returns the previously stored value of that type, if present.

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pub fn get<T>(&self) -> Option<&T>
where T: 'static + Sync + Send,

Returns a shared reference to the stored value of the specified type.

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pub fn get_mut<T>(&mut self) -> Option<&mut T>
where T: 'static + Sync + Send,

Returns a mutable reference to the stored value of the specified type.

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pub fn remove<T>(&mut self) -> Option<T>
where T: 'static + Sync + Send,

Removes the value of the specified type from the map, returning it.

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pub fn clear(&mut self)

Removes all values from the map.

Trait Implementations§

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impl Default for Extensions

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fn default() -> Extensions

Returns the “default value” for a type. Read more

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for T
where 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 T
where 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 T
where 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 T
where 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>

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>

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

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fn vzip(self) -> V