Struct collections::boxed::IntermediateBox [−] [src]

pub struct IntermediateBox<T> where T: ?Sized {
    ptr: *mut u8,
    size: usize,
    align: usize,
    marker: PhantomData<*mut T>,
}

Unstable (placement_in #27779)
: placement box design is still being worked out.

IntermediateBox represents uninitialized backing storage for Box.

FIXME (pnkfelix): Ideally we would just reuse Box<T> instead of introducing a separate IntermediateBox<T>; but then you hit issues when you e.g. attempt to destructure an instance of Box, since it is a lang item and so it gets special handling by the compiler. Easier just to make this parallel type for now.

FIXME (pnkfelix): Currently the box protocol only supports creating instances of sized types. This IntermediateBox is designed to be forward-compatible with a future protocol that supports creating instances of unsized types; that is why the type parameter has the ?Sized generalization marker, and is also why this carries an explicit size. However, it probably does not need to carry the explicit alignment; that is just a work-around for the fact that the align_of intrinsic currently requires the input type to be Sized (which I do not think is strictly necessary).

Fields

`ptr`	Unstable (`placement_in` #27779) : placement box design is still being worked out.
`size`	Unstable (`placement_in` #27779) : placement box design is still being worked out.
`align`	Unstable (`placement_in` #27779) : placement box design is still being worked out.
`marker`	Unstable (`placement_in` #27779) : placement box design is still being worked out.

Trait Implementations

Struct collections::boxed::IntermediateBox [−] [src]

Fields

Trait Implementations

`impl<T> Place<T> for IntermediateBox<T>`

`fn pointer(&mut self) -> *mut T`

`impl<T> BoxPlace<T> for IntermediateBox<T>`

`fn make_place() -> IntermediateBox<T>`

`impl<T> InPlace<T> for IntermediateBox<T>`

`type Owner = Box<T>`

`unsafe fn finalize(self) -> Box<T>`

`impl<T> Drop for IntermediateBox<T> where T: ?Sized`

`fn drop(&mut self)`