Enum windows_helpers::FirstCallExpectation

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#[non_exhaustive]
pub enum FirstCallExpectation<T> {
    Ok,
    OkValue(T),
    Win32Error(WIN32_ERROR),
    HResultError(HRESULT),
}
Expand description

Defining the return value of the first call of dual_call() that is the precondition to continue with the second call.

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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Ok

Useful with a function like GetKeyboardLayoutList().

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OkValue(T)

Useful with a function like AssocQueryStringW().

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Win32Error(WIN32_ERROR)

The most useful. Requires ERROR_INSUFFICIENT_BUFFER most often, if not documented.

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HResultError(HRESULT)

Useful with a function like AssocQueryStringW() (in ASSOCF_NOTRUNCATE mode).

Auto Trait Implementations§

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impl<T> RefUnwindSafe for FirstCallExpectation<T>
where T: RefUnwindSafe,

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impl<T> Send for FirstCallExpectation<T>
where T: Send,

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impl<T> Sync for FirstCallExpectation<T>
where T: Sync,

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impl<T> Unpin for FirstCallExpectation<T>
where T: Unpin,

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impl<T> UnwindSafe for FirstCallExpectation<T>
where T: UnwindSafe,

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> MapSelf for T

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fn map_self<O, T>(self, op: O) -> T
where O: FnOnce(Self) -> T, Self: Sized,

Example: Read more
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fn map_self_or_keep<O>(self, op: O) -> Self
where O: FnOnce(&Self) -> Option<Self>, Self: Sized,

Example: 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.