no_std_compat::ffi

Enum 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§

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impl Freeze for c_void

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impl RefUnwindSafe for c_void

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impl Send for c_void

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impl Sync for c_void

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impl Unpin for c_void

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impl UnwindSafe for c_void

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, 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.