Trait Dst 

pub unsafe trait Dst {
    // Required methods
    fn len(&self) -> usize;
    fn layout(len: usize) -> Result<Layout, LayoutError>;
    fn retype(ptr: NonNull<u8>, len: usize) -> NonNull<Self>;

    // Provided method
    fn is_empty(&self) -> bool { ... }
}

A dynamically sized type.

Safety

Must be implemented as described.

Required Methods

fn len(&self) -> usize

The length of the DST.

Note that this is NOT the size of the type, for that you should use Layout::for_value or Dst::layout.

fn layout(len: usize) -> Result<Layout, LayoutError>

Returns the layout of the DST, assuming it has the given length.

Errors

Returns a LayoutError if calculation of the layout fails.

fn retype(ptr: NonNull<u8>, len: usize) -> NonNull<Self>

Convert the given thin pointer to a fat pointer to the DST, adding the length to the metadata.

Safety

This function is safe but the returned pointer is not necessarily safe to dereference.

Provided Methods

fn is_empty(&self) -> bool

Counterpart to len. Mainly exists to please clippy.

The default implementation simply checks if the len equals 0.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl Dst for str

fn len(&self) -> usize

fn layout(len: usize) -> Result<Layout, LayoutError>

fn retype(ptr: NonNull<u8>, len: usize) -> NonNull<Self>

impl<T> Dst for [T]

fn len(&self) -> usize

fn layout(len: usize) -> Result<Layout, LayoutError>

fn retype(ptr: NonNull<u8>, len: usize) -> NonNull<Self>

Implementors