Struct Cursor

pub struct Cursor<'a, T, const N: usize> { /* private fields */ }

A fixed-size cursor for initializing MaybeUninit arrays

The cursor will guarantee that all values have been initialized when the value is dropped, which means that it is safe to call MaybeUninit::assume_init().

NOTE: This guarantee only holds as long as Drop::drop() is called. If the value goes out of scope without drop being called (e.g. because of core::mem::forget()), then this guarantee no longer applies.

Implementations

impl<'a, T, const N: usize> Cursor<'a, T, N>

pub fn new(slice: &'a mut [MaybeUninit<T>; N]) -> Self

Creates a new cursor.

pub fn finish(self, value: [T; N])

Finishes the buffer by writing the remaining values.

This is equivalent to calling self.write::<N, 0>(value), except it is slightly more ergonomic.

pub fn write<const L: usize, const R: usize>( self, value: [T; L], ) -> Cursor<'a, T, R>

Writes L values to the buffer and returns a new cursor for the remaining R values.

This function cannot compile unless L + R == N, however it will be able to pass through cargo check, since the error is not discovered by rustc until it tries to instantiate the code.

pub fn split<const L: usize, const R: usize>( self, ) -> (Cursor<'a, T, L>, Cursor<'a, T, R>)

Splits the cursor in two.

This function cannot compile unless L + R == N, however it will be able to pass through cargo check, since the error is not discovered by rustc until it tries to instantiate the code.

pub fn assert_size<const M: usize>(self) -> Cursor<'a, T, M>

Compile-time assertion that N == M to work-around limitations in rust generics.

This is useful if a type-signature requires the function to have a generic size argument, but you want compile-time errors when called with the wrong parameter.

Examples

fn example<const N: usize>(cursor: array_init_cursor::Cursor<'_, u8, N>) {
    let cursor: array_init_cursor::Cursor<u8, 10> = cursor.assert_size();
}

Trait Implementations

impl<'a, T, const N: usize> Drop for Cursor<'a, T, N>

fn drop(&mut self)

Will panic unless cursor has been completely initialized