Struct Frame 

pub struct Frame<C: Ctxt> { /* private fields */ }

A set of ambient properties that are cleaned up automatically.

This type is a wrapper around a Ctxt that simplifies ambient property management. A frame containing ambient properties can be created through Frame::push or Frame::root. Those properties can be activated by calling Frame::enter. The returned EnterGuard will automatically deactivate those properties when dropped.

A frame can be converted into a future through Frame::in_future that enters and exits on each call to Future::poll so ambient properties can follow a future as it executes in an async runtime.

Implementations

impl<C: Ctxt> Frame<C>

pub fn current(ctxt: C) -> Self

Get a frame with the current set of ambient properties.

pub fn push(ctxt: C, props: impl Props) -> Self

Get a frame with the given props pushed to the current set.

pub fn root(ctxt: C, props: impl Props) -> Self

Get a frame for just the properties in props.

pub fn disabled(ctxt: C, props: impl Props) -> Self

Get a disabled frame.

The properties in props will not be visible when the frame is entered. This method should be used when props could have been pushed, but were filtered out.

Even though this frame isn’t expected to have a visible impact on the current set of ambient properties it’s still expected to be entered and exited as normal.

pub fn filtered(ctxt: C, filter: impl Fn(Str<'_>, Value<'_>) -> bool) -> Self

Get a frame with the given filter applied.

The properties visible when the frame is entered will be the current set that matches filter.

pub fn with<R>(&mut self, with: impl FnOnce(&C::Current) -> R) -> R

Access the properties in this frame.

pub fn enter(&mut self) -> EnterGuard<'_, C>

Activate this frame.

The properties in this frame will be visible until the returned EnterGuard is dropped.

pub fn call<R>(self, scope: impl FnOnce() -> R) -> R

Activate this frame for the duration of scope.

The properties in this frame will be visible while scope is executing.

pub fn in_fn<R>(self, scope: impl FnOnce() -> R) -> impl FnOnce() -> R

Get a FnOnce that will activate this frame when invoked.

The properties in this frame will be visible while scope is executing.

Similar to Self::call(), except that it returns a function which can be passed to some other function, e.g.: std::thread::spawn.

pub fn in_future<F>(self, future: F) -> FrameFuture<C, F>

Get a future that will activate this frame on each call to Future::poll.

The properties in this frame will be visible while the inner future is executing.

pub fn inner(&self) -> &C::Frame

Get a reference to the underlying context frame.

pub fn inner_mut(&mut self) -> &mut C::Frame

Get an exclusive reference to the underlying context frame.

pub const fn from_parts(ctxt: C, scope: C::Frame) -> Self

Create a frame from its constituent parts.

In order to be correct, this method requires:

1. That scope was created by ctxt.
2. That scope is not currently entered.

pub fn into_parts(self) -> (C, C::Frame)

Split the frame into its raw parts.

The original frame can be re-constituted by calling Frame::from_parts.

Trait Implementations

impl<C: Ctxt> Drop for Frame<C>

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.