Struct servo::panic::AssertUnwindSafe1.9.0[][src]

pub struct AssertUnwindSafe<T>(pub T);
Expand description

A simple wrapper around a type to assert that it is unwind safe.

When using catch_unwind it may be the case that some of the closed over variables are not unwind safe. For example if &mut T is captured the compiler will generate a warning indicating that it is not unwind safe. It might not be the case, however, that this is actually a problem due to the specific usage of catch_unwind if unwind safety is specifically taken into account. This wrapper struct is useful for a quick and lightweight annotation that a variable is indeed unwind safe.

Examples

One way to use AssertUnwindSafe is to assert that the entire closure itself is unwind safe, bypassing all checks for all variables:

use std::panic::{self, AssertUnwindSafe};

let mut variable = 4;

// This code will not compile because the closure captures `&mut variable`
// which is not considered unwind safe by default.

// panic::catch_unwind(|| {
//     variable += 3;
// });

// This, however, will compile due to the `AssertUnwindSafe` wrapper
let result = panic::catch_unwind(AssertUnwindSafe(|| {
    variable += 3;
}));
// ...

Wrapping the entire closure amounts to a blanket assertion that all captured variables are unwind safe. This has the downside that if new captures are added in the future, they will also be considered unwind safe. Therefore, you may prefer to just wrap individual captures, as shown below. This is more annotation, but it ensures that if a new capture is added which is not unwind safe, you will get a compilation error at that time, which will allow you to consider whether that new capture in fact represent a bug or not.

use std::panic::{self, AssertUnwindSafe};

let mut variable = 4;
let other_capture = 3;

let result = {
    let mut wrapper = AssertUnwindSafe(&mut variable);
    panic::catch_unwind(move || {
        **wrapper += other_capture;
    })
};
// ...

Tuple Fields

0: T

Trait Implementations

Formats the value using the given formatter. Read more

The resulting type after dereferencing.

Dereferences the value.

Mutably dereferences the value.

The returned type after the call operator is used.

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

Performs the call operation.

Returns true if the underlying future should no longer be polled.

The type of value produced on completion.

Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available. Read more

The type of value that this future will resolved with if it is successful. Read more

The type of error that this future will resolve with if it fails in a normal fashion. Read more

Query this future to see if its value has become available, registering interest if it is not. Read more

Block the current thread until this future is resolved. Read more

Map this future’s result to a different type, returning a new future of the resulting type. Read more

Map this future’s error to a different error, returning a new future. Read more

Map this future’s error to any error implementing From for this future’s Error, returning a new future. Read more

Chain on a computation for when a future finished, passing the result of the future to the provided closure f. Read more

Execute another future after this one has resolved successfully. Read more

Execute another future if this one resolves with an error. Read more

Waits for either one of two futures to complete. Read more

Waits for either one of two differently-typed futures to complete. Read more

Joins the result of two futures, waiting for them both to complete. Read more

Same as join, but with more futures.

Same as join, but with more futures.

Same as join, but with more futures.

Convert this future into a single element stream. Read more

Flatten the execution of this future when the successful result of this future is itself another future. Read more

Flatten the execution of this future when the successful result of this future is a stream. Read more

Fuse a future such that poll will never again be called once it has completed. Read more

Do something with the item of a future, passing it on. Read more

Catches unwinding panics while polling the future. Read more

Create a cloneable handle to this future where all handles will resolve to the same result. Read more

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

The type of items yielded by the stream.

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

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted. Read more

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

Returns the bounds on the remaining length of the stream. Read more

The type of item this stream will yield on success.

The type of error this stream may generate.

Attempt to pull out the next value of this stream, returning None if the stream is finished. Read more

Creates an iterator which blocks the current thread until each item of this stream is resolved. Read more

Converts this stream into a Future. Read more

Converts a stream of type T to a stream of type U. Read more

Converts a stream of error type T to a stream of error type U. Read more

Filters the values produced by this stream according to the provided predicate. Read more

Filters the values produced by this stream while simultaneously mapping them to a different type. Read more

Chain on a computation for when a value is ready, passing the resulting item to the provided closure f. Read more

Chain on a computation for when a value is ready, passing the successful results to the provided closure f. Read more

Chain on a computation for when an error happens, passing the erroneous result to the provided closure f. Read more

Collect all of the values of this stream into a vector, returning a future representing the result of that computation. Read more

Concatenate all results of a stream into a single extendable destination, returning a future representing the end result. Read more

👎 Deprecated since 0.1.14:

please use Stream::concat2 instead

Concatenate all results of a stream into a single extendable destination, returning a future representing the end result. Read more

Execute an accumulating computation over a stream, collecting all the values into one final result. Read more

Flattens a stream of streams into just one continuous stream. Read more

Skip elements on this stream while the predicate provided resolves to true. Read more

Take elements from this stream while the predicate provided resolves to true. Read more

Runs this stream to completion, executing the provided closure for each element on the stream. Read more

Map this stream’s error to any error implementing From for this stream’s Error, returning a new stream. Read more

Creates a new stream of at most amt items of the underlying stream. Read more

Creates a new stream which skips amt items of the underlying stream. Read more

Fuse a stream such that poll will never again be called once it has finished. Read more

Borrows a stream, rather than consuming it. Read more

Catches unwinding panics while polling the stream. Read more

An adaptor for creating a buffered list of pending futures. Read more

An adaptor for creating a buffered list of pending futures (unordered). Read more

👎 Deprecated:

functionality provided by select now

An adapter for merging the output of two streams. Read more

An adapter for zipping two streams together. Read more

Adapter for chaining two stream. Read more

Creates a new stream which exposes a peek method. Read more

An adaptor for chunking up items of the stream inside a vector. Read more

Creates a stream that selects the next element from either this stream or the provided one, whichever is ready first. Read more

A future that completes after the given stream has been fully processed into the sink, including flushing. Read more

Splits this Stream + Sink object into separate Stream and Sink objects. Read more

Do something with each item of this stream, afterwards passing it on. Read more

Do something with the error of this stream, afterwards passing it on. Read more

Values yielded by the stream.

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted. Read more

Returns the bounds on the remaining length of the stream. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Performs the conversion.

Creates a new future which allows self until timeout. Read more

Map this future’s output to a different type, returning a new future of the resulting type. Read more

Map this future’s output to a different type, returning a new future of the resulting type. Read more

Chain on a computation for when a future finished, passing the result of the future to the provided closure f. Read more

Wrap this future in an Either future, making it the left-hand variant of that Either. Read more

Wrap this future in an Either future, making it the right-hand variant of that Either. Read more

Convert this future into a single element stream. Read more

Flatten the execution of this future when the output of this future is itself another future. Read more

Flatten the execution of this future when the successful result of this future is a stream. Read more

Fuse a future such that poll will never again be called once it has completed. This method can be used to turn any Future into a FusedFuture. Read more

Do something with the output of a future before passing it on. Read more

Catches unwinding panics while polling the future. Read more

Create a cloneable handle to this future where all handles will resolve to the same result. Read more

Turn this future into a future that yields () on completion and sends its output to another future on a separate task. Read more

Wrap the future in a Box, pinning it. Read more

Wrap the future in a Box, pinning it. Read more

A convenience for calling Future::poll on Unpin future types.

Evaluates and consumes the future, returning the resulting output if the future is ready after the first call to Future::poll. Read more

Performs the conversion.

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

The output that the future will produce on completion.

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

Which kind of future are we turning this into?

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

Creates a future from a value.

The future that this type can be converted into.

The item that the future may resolve with.

The error that the future may resolve with.

Consumes this object and produces a future.

Convert

Convert

The alignment of pointer.

The type for initializers.

Initializes a with the given initializer. Read more

Dereferences the given pointer. Read more

Mutably dereferences the given pointer. Read more

Drops the object pointed to by the given pointer. Read more

Should always be Self

Throttle down the stream by enforcing a fixed delay between items. Read more

Creates a new stream which gives the current iteration count as well as the next value. Read more

Creates a new stream which allows self until timeout. Read more

Creates a future that resolves to the next item in the stream. Read more

Converts this stream into a future of (next_item, tail_of_stream). If the stream terminates, then the next item is None. Read more

Maps this stream’s items to a different type, returning a new stream of the resulting type. Read more

Creates a stream which gives the current iteration count as well as the next value. Read more

Filters the values produced by this stream according to the provided asynchronous predicate. Read more

Filters the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more

Computes from this stream’s items new items of a different type using an asynchronous closure. Read more

Transforms a stream into a collection, returning a future representing the result of that computation. Read more

Concatenate all items of a stream into a single extendable destination, returning a future representing the end result. Read more

Repeats a stream endlessly. Read more

Execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more

Flattens a stream of streams into just one continuous stream. Read more

Maps a stream like StreamExt::map but flattens nested Streams. Read more

Combinator similar to StreamExt::fold that holds internal state and produces a new stream. Read more

Skip elements on this stream while the provided asynchronous predicate resolves to true. Read more

Take elements from this stream while the provided asynchronous predicate resolves to true. Read more

Take elements from this stream until the provided future resolves. Read more

Runs this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more

Runs this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available. Read more

Creates a new stream of at most n items of the underlying stream. Read more

Creates a new stream which skips n items of the underlying stream. Read more

Fuse a stream such that poll_next will never again be called once it has finished. This method can be used to turn any Stream into a FusedStream. Read more

Borrows a stream, rather than consuming it. Read more

Catches unwinding panics while polling the stream. Read more

Wrap the stream in a Box, pinning it. Read more

Wrap the stream in a Box, pinning it. Read more

An adaptor for creating a buffered list of pending futures. Read more

An adaptor for creating a buffered list of pending futures (unordered). Read more

An adapter for zipping two streams together. Read more

Adapter for chaining two streams. Read more

Creates a new stream which exposes a peek method. Read more

An adaptor for chunking up items of the stream inside a vector. Read more

An adaptor for chunking up ready items of the stream inside a vector. Read more

A future that completes after the given stream has been fully processed into the sink and the sink has been flushed and closed. Read more

Splits this Stream + Sink object into separate Sink and Stream objects. Read more

Do something with each item of this stream, afterwards passing it on. Read more

Wrap this stream in an Either stream, making it the left-hand variant of that Either. Read more

Wrap this stream in an Either stream, making it the right-hand variant of that Either. Read more

A convenience method for calling Stream::poll_next on Unpin stream types. Read more

Returns a Future that resolves when the next item in this stream is ready. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type of successful values yielded by this future

The type of failures yielded by this future

Poll this TryFuture as if it were a Future. Read more

Flattens the execution of this future when the successful result of this future is a Sink. Read more

Maps this future’s success value to a different value. Read more

Maps this future’s success value to a different value, and permits for error handling resulting in the same type. Read more

Maps this future’s error value to a different value. Read more

Maps this future’s Error to a new error type using the Into trait. Read more

Maps this future’s Ok to a new type using the Into trait. Read more

Executes another future after this one resolves successfully. The success value is passed to a closure to create this subsequent future. Read more

Executes another future if this one resolves to an error. The error value is passed to a closure to create this subsequent future. Read more

Do something with the success value of a future before passing it on. Read more

Do something with the error value of a future before passing it on. Read more

Flatten the execution of this future when the successful result of this future is another future. Read more

Flatten the execution of this future when the successful result of this future is a stream. Read more

Unwraps this future’s ouput, producing a future with this future’s Ok type as its Output type. Read more

Wraps a TryFuture into a type that implements Future. Read more

A convenience method for calling TryFuture::try_poll on Unpin future types. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type of successful values yielded by this future

The type of failures yielded by this future

Poll this TryStream as if it were a Stream. Read more

Wraps the current stream in a new stream which converts the error type into the one provided. Read more

Wraps the current stream in a new stream which maps the success value using the provided closure. Read more

Wraps the current stream in a new stream which maps the error value using the provided closure. Read more

Chain on a computation for when a value is ready, passing the successful results to the provided closure f. Read more

Chain on a computation for when an error happens, passing the erroneous result to the provided closure f. Read more

Do something with the success value of this stream, afterwards passing it on. Read more

Do something with the error value of this stream, afterwards passing it on. Read more

Wraps a TryStream into a type that implements Stream Read more

Creates a future that attempts to resolve the next item in the stream. If an error is encountered before the next item, the error is returned instead. Read more

Attempts to run this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more

Skip elements on this stream while the provided asynchronous predicate resolves to true. Read more

Take elements on this stream while the provided asynchronous predicate resolves to true. Read more

Attempts to run this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available, exiting as soon as an error occurs. Read more

Attempt to transform a stream into a collection, returning a future representing the result of that computation. Read more

Attempt to filter the values produced by this stream according to the provided asynchronous closure. Read more

Attempt to filter the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more

Flattens a stream of streams into just one continuous stream. Read more

Attempt to execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more

Attempt to concatenate all items of a stream into a single extendable destination, returning a future representing the end result. Read more

Attempt to execute several futures from a stream concurrently (unordered). Read more

Attempt to execute several futures from a stream concurrently. Read more

A convenience method for calling TryStream::try_poll_next on Unpin stream types. Read more

Adapter that converts this stream into an AsyncRead. Read more