Enum std::ffi::c_void

1.30.0 · source ·
#[repr(u8)]
pub enum c_void { // some variants omitted }
Expand description

Equivalent to C’s void type when used as a pointer.

In essence, *const c_void is equivalent to C’s const void* and *mut c_void is equivalent to C’s void*. That said, this is not the same as C’s void return type, which is Rust’s () type.

To model pointers to opaque types in FFI, until extern type is stabilized, it is recommended to use a newtype wrapper around an empty byte array. See the Nomicon for details.

One could use std::os::raw::c_void if they want to support old Rust compiler down to 1.1.0. After Rust 1.30.0, it was re-exported by this definition. For more information, please read RFC 2521.

Trait Implementations§

1.16.0 · source§

impl Debug for c_void

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fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter. Read more

Auto Trait Implementations§

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, 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.