Struct varlen::FixedLen

pub struct FixedLen<T>(pub T);

Presents a fixed-length type T as a variable-length type.

Useful for creating tuples consisting of some variable-length types and some fixed-length types.

Examples

Put a fixed-length type in a variable-sized box:

use varlen::prelude::*;
let b: VBox<FixedLen<u16>> = VBox::new(FixedLen(4));
assert_eq!(b.0, 4);

Create a tuple of variable-length types and a fixed-length type:

use varlen::prelude::*;
let b: VBox<Tup2<FixedLen<u16>, Str>> = VBox::new(tup2::Init(
    FixedLen(4), Str::copy("hello")));
assert_eq!(b.refs().0.0, 4);
assert_eq!(&b.refs().1[..], "hello");

Tuple Fields

0: T

Trait Implementations

impl<T> Initializer<FixedLen<T>> for FixedLen<T>

fn calculate_layout_cautious(&self) -> Option<FixedLenLayout<T>>

Calculates the layout of the object, returning None if any of the calculated sizes or offsets would overflow usize.

unsafe fn initialize(
    self,
    dst: NonNull<FixedLen<T>>,
    _layout: FixedLenLayout<T>
)

Populates the destination pointer.

impl<'a, T: Clone> Initializer<FixedLen<T>> for FixedLenCloner<'a, T>

fn calculate_layout_cautious(&self) -> Option<FixedLenLayout<T>>

Calculates the layout of the object, returning None if any of the calculated sizes or offsets would overflow usize.

unsafe fn initialize(
    self,
    dst: NonNull<FixedLen<T>>,
    _layout: FixedLenLayout<T>
)

Populates the destination pointer.

impl<'a, T: 'a + Clone> VClone<'a> for FixedLen<T>

type Cloner = FixedLenCloner<'a, T>

An initializer that can produce a clone of an object of type Self.

fn vclone(&'a self) -> Self::Cloner

Returns an initializer that will clone self when run.

impl<'a, T: 'a + Copy> VCopy<'a> for FixedLen<T>

fn vcopy(&'a self) -> VCopier<'a, Self>

Returns an initializer that does a bulk byte copy of self.

impl<T> VarLen for FixedLen<T>

type Layout = FixedLenLayout<T>

This type’s internal dynamic calculations of where its tail fields are.

fn calculate_layout(&self) -> Self::Layout

Calculates the layout of the internal fields of this object.

const ALIGN: usize

Alignment of this type, including its fixed-length header.

const NEEDS_VDROP: bool

If false, vdrop() is a noop, and may be skipped without changing behavior.

unsafe fn vdrop(self: Pin<&mut Self>, _layout: Self::Layout)

Drops self.