Trait slice_dst::AllocSliceDst

pub unsafe trait AllocSliceDst<S: ?Sized + SliceDst> {
    unsafe fn new_slice_dst<I>(len: usize, init: I) -> Self
    where
        I: FnOnce(NonNull<S>);
}

Types that can allocate a custom slice DST within them.

Implementation note

For most types, TryAllocSliceDst should be the implementation primitive. This trait can then be implemented in terms of TryAllocSliceDst:

unsafe impl<S: ?Sized + SliceDst> AllocSliceDst<S> for Container<S> {
    unsafe fn new_slice_dst<I>(len: usize, init: I) -> Self
    where
        I: FnOnce(ptr::NonNull<S>),
    {
        enum Void {} // or never (!) once it is stable
        #[allow(clippy::unit_arg)]
        let init = |ptr| Ok::<(), Void>(init(ptr));
        match Self::try_new_slice_dst(len, init) {
            Ok(a) => a,
            Err(void) => match void {},
        }
    }
}

This is not a blanket impl due to coherence rules; if the blanket impl were present, it would be impossible to implement AllocSliceDst instead of TryAllocSliceDst.

Required methods

unsafe fn new_slice_dst<I>(len: usize, init: I) -> Self where
    I: FnOnce(NonNull<S>), 

Create a new custom slice DST.

Safety

init must properly initialize the object behind the pointer. init receives a fully uninitialized pointer and must not read anything before writing.

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Implementations on Foreign Types

impl<S: ?Sized + SliceDst> AllocSliceDst<S> for Box<S>

unsafe fn new_slice_dst<I>(len: usize, init: I) -> Self where
    I: FnOnce(NonNull<S>), 

impl<S: ?Sized + SliceDst> AllocSliceDst<S> for Rc<S>

unsafe fn new_slice_dst<I>(len: usize, init: I) -> Self where
    I: FnOnce(NonNull<S>), 

impl<S: ?Sized + SliceDst> AllocSliceDst<S> for Arc<S>

unsafe fn new_slice_dst<I>(len: usize, init: I) -> Self where
    I: FnOnce(NonNull<S>), 

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Implementors

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