Struct esp_idf_svc::hal::peripheral::PeripheralRef

pub struct PeripheralRef<'a, T> { /* private fields */ }

An exclusive reference to a peripheral.

This is functionally the same as a &'a mut T. The reason for having a dedicated struct is memory efficiency:

Peripheral singletons are typically either zero-sized (for concrete peripehrals like PA9 or Spi4) or very small (for example AnyPin which is 1 byte). However &mut T is always 4 bytes for 32-bit targets, even if T is zero-sized. PeripheralRef stores a copy of T instead, so it’s the same size.

but it is the size of T not the size of a pointer. This is useful if T is a zero sized type.

Implementations

impl<'a, T> PeripheralRef<'a, T>

pub fn new(inner: T) -> PeripheralRef<'a, T>

pub unsafe fn clone_unchecked(&mut self) -> PeripheralRef<'a, T>

where T: Peripheral<P = T>,

Unsafely clone (duplicate) a peripheral singleton.

Safety

This returns an owned clone of the peripheral. You must manually ensure only one copy of the peripheral is in use at a time. For example, don’t create two SPI drivers on SPI1, because they will “fight” each other.

You should strongly prefer using reborrow() instead. It returns a PeripheralRef that borrows self, which allows the borrow checker to enforce this at compile time.

pub fn reborrow(&mut self) -> PeripheralRef<'_, T>

where T: Peripheral<P = T>,

Reborrow into a “child” PeripheralRef.

self will stay borrowed until the child PeripheralRef is dropped.

pub fn map_into<U>(self) -> PeripheralRef<'a, U>

where T: Into<U>,

Map the inner peripheral using Into.

This converts from PeripheralRef<'a, T> to PeripheralRef<'a, U>, using an Into impl to convert from T to U.

For example, this can be useful to degrade GPIO pins: converting from PeripheralRef<’a, PB11>toPeripheralRef<’a, AnyPin>`.

Trait Implementations

impl<'a, T> Deref for PeripheralRef<'a, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &<PeripheralRef<'a, T> as Deref>::Target

Dereferences the value.

impl<'a, T> DerefMut for PeripheralRef<'a, T>

fn deref_mut(&mut self) -> &mut <PeripheralRef<'a, T> as Deref>::Target

Mutably dereferences the value.