std::ffi::c_void - Rust
Description: API documentation for the Rust `c_void` enum in crate `std`.
Keywords: rust, rustlang, rust-lang, c_void

# 1.30.0[−][src]Enum std::ffi::c_void

    #[repr(u8)]
    pub enum c_void {
        // some variants omitted
    }

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

### `impl Debug for c_void` 1.16.0[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

Formats the value using the given formatter. Read more

## Auto Trait Implementations

### `impl UnwindSafe for c_void`

### `impl RefUnwindSafe for c_void`

### `impl Unpin for c_void`

### `impl Send for c_void`

### `impl Sync for c_void`

## Blanket Implementations

### `impl<T> From<T> for T`[src]

#### `fn from(t: T) -> T`[src]

Performs the conversion.

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>`[src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `fn into(self) -> U`[src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

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

The type returned in the event of a conversion error.

#### `fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>`[src]

Performs the conversion.

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

####
ⓘImportant traits for &'_ mut I

### Important traits for &'_ mut I

`impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, R: Read + ?Sized> Read for &'_ mut Rimpl<'_, W: Write + ?Sized> Write for &'_ mut W`
`fn borrow(&self) -> &T`[src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

####
ⓘImportant traits for &'_ mut I

### Important traits for &'_ mut I

`impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, R: Read + ?Sized> Read for &'_ mut Rimpl<'_, W: Write + ?Sized> Write for &'_ mut W`
`fn borrow_mut(&mut self) -> &mut T`[src]

Mutably borrows from an owned value. Read more

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `fn type_id(&self) -> TypeId`[src]

Gets the `TypeId` of `self`. Read more