Struct otter_api_tests::otter_support::imports::io::StdinLock
1.0.0 · source · [−]pub struct StdinLock<'a> { /* private fields */ }
Expand description
A locked reference to the Stdin
handle.
This handle implements both the Read
and BufRead
traits, and
is constructed via the Stdin::lock
method.
Note: Windows Portability Considerations
When operating in a console, the Windows implementation of this stream does not support non-UTF-8 byte sequences. Attempting to read bytes that are not valid UTF-8 will return an error.
In a process with a detached console, such as one using
#![windows_subsystem = "windows"]
, or in a child process spawned from such a process,
the contained handle will be null. In such cases, the standard library’s Read
and
Write
will do nothing and silently succeed. All other I/O operations, via the
standard library or via raw Windows API calls, will fail.
Examples
use std::io::{self, BufRead};
fn main() -> io::Result<()> {
let mut buffer = String::new();
let stdin = io::stdin(); // We get `Stdin` here.
{
let mut handle = stdin.lock(); // We get `StdinLock` here.
handle.read_line(&mut buffer)?;
} // `StdinLock` is dropped here.
Ok(())
}
Trait Implementations
1.63.0 · sourceimpl<'a> AsFd for StdinLock<'a>
impl<'a> AsFd for StdinLock<'a>
sourcefn as_fd(&self) -> BorrowedFd<'_>
fn as_fd(&self) -> BorrowedFd<'_>
Borrows the file descriptor. Read more
sourceimpl<'_> BufRead for StdinLock<'_>
impl<'_> BufRead for StdinLock<'_>
sourcefn fill_buf(&mut self) -> Result<&[u8], Error>
fn fill_buf(&mut self) -> Result<&[u8], Error>
Returns the contents of the internal buffer, filling it with more data from the inner reader if it is empty. Read more
sourcefn consume(&mut self, n: usize)
fn consume(&mut self, n: usize)
Tells this buffer that amt
bytes have been consumed from the buffer,
so they should no longer be returned in calls to read
. Read more
sourcefn read_until(
&mut self,
byte: u8,
buf: &mut Vec<u8, Global>
) -> Result<usize, Error>
fn read_until(
&mut self,
byte: u8,
buf: &mut Vec<u8, Global>
) -> Result<usize, Error>
Read all bytes into buf
until the delimiter byte
or EOF is reached. Read more
sourcefn read_line(&mut self, buf: &mut String) -> Result<usize, Error>
fn read_line(&mut self, buf: &mut String) -> Result<usize, Error>
Read all bytes until a newline (the 0xA
byte) is reached, and append
them to the provided buffer. You do not need to clear the buffer before
appending. Read more
sourcefn has_data_left(&mut self) -> Result<bool, Error>
fn has_data_left(&mut self) -> Result<bool, Error>
buf_read_has_data_left
)Check if the underlying Read
has any data left to be read. Read more
sourceimpl<'_> Read for StdinLock<'_>
impl<'_> Read for StdinLock<'_>
sourcefn read(&mut self, buf: &mut [u8]) -> Result<usize, Error>
fn read(&mut self, buf: &mut [u8]) -> Result<usize, Error>
Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more
sourcefn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>
fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>
Like read
, except that it reads into a slice of buffers. Read more
sourcefn is_read_vectored(&self) -> bool
fn is_read_vectored(&self) -> bool
can_vector
)Determines if this Read
er has an efficient read_vectored
implementation. Read more
sourcefn read_to_end(&mut self, buf: &mut Vec<u8, Global>) -> Result<usize, Error>
fn read_to_end(&mut self, buf: &mut Vec<u8, Global>) -> Result<usize, Error>
Read all bytes until EOF in this source, placing them into buf
. Read more
sourcefn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>
fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>
Read all bytes until EOF in this source, appending them to buf
. Read more
sourcefn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>
fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>
Read the exact number of bytes required to fill buf
. Read more
sourcefn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> Result<(), Error>
fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> Result<(), Error>
read_buf
)Pull some bytes from this source into the specified buffer. Read more
sourcefn read_buf_exact(&mut self, buf: &mut ReadBuf<'_>) -> Result<(), Error>
fn read_buf_exact(&mut self, buf: &mut ReadBuf<'_>) -> Result<(), Error>
read_buf
)Read the exact number of bytes required to fill buf
. Read more
sourcefn by_ref(&mut self) -> &mut Self
fn by_ref(&mut self) -> &mut Self
Creates a “by reference” adaptor for this instance of Read
. Read more
sourcefn bytes(self) -> Bytes<Self>ⓘNotable traits for Bytes<R>impl<R> Iterator for Bytes<R> where
R: Read, type Item = Result<u8, Error>;
fn bytes(self) -> Bytes<Self>ⓘNotable traits for Bytes<R>impl<R> Iterator for Bytes<R> where
R: Read, type Item = Result<u8, Error>;
R: Read, type Item = Result<u8, Error>;
Auto Trait Implementations
impl<'a> RefUnwindSafe for StdinLock<'a>
impl<'a> !Send for StdinLock<'a>
impl<'a> Sync for StdinLock<'a>
impl<'a> Unpin for StdinLock<'a>
impl<'a> UnwindSafe for StdinLock<'a>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
impl<B> BufReadExt for B where
B: BufRead,
impl<B> BufReadExt for B where
B: BufRead,
fn byte_lines(self) -> ByteLines<Self>ⓘNotable traits for ByteLines<B>impl<B> Iterator for ByteLines<B> where
B: BufRead, type Item = Result<Vec<u8, Global>, Error>;
fn byte_lines(self) -> ByteLines<Self>ⓘNotable traits for ByteLines<B>impl<B> Iterator for ByteLines<B> where
B: BufRead, type Item = Result<Vec<u8, Global>, Error>;
B: BufRead, type Item = Result<Vec<u8, Global>, Error>;
Returns an iterator over the lines of this reader, where each line is represented as a byte string. Read more
fn byte_records(self, terminator: u8) -> ByteRecords<Self>ⓘNotable traits for ByteRecords<B>impl<B> Iterator for ByteRecords<B> where
B: BufRead, type Item = Result<Vec<u8, Global>, Error>;
fn byte_records(self, terminator: u8) -> ByteRecords<Self>ⓘNotable traits for ByteRecords<B>impl<B> Iterator for ByteRecords<B> where
B: BufRead, type Item = Result<Vec<u8, Global>, Error>;
B: BufRead, type Item = Result<Vec<u8, Global>, Error>;
Returns an iterator over byte-terminated records of this reader, where each record is represented as a byte string. Read more
fn for_byte_line<F>(self, for_each_line: F) -> Result<(), Error> where
F: for<'_> FnMut(&[u8]) -> Result<bool, Error>,
fn for_byte_line<F>(self, for_each_line: F) -> Result<(), Error> where
F: for<'_> FnMut(&[u8]) -> Result<bool, Error>,
Executes the given closure on each line in the underlying reader. Read more
fn for_byte_record<F>(
self,
terminator: u8,
for_each_record: F
) -> Result<(), Error> where
F: for<'_> FnMut(&[u8]) -> Result<bool, Error>,
fn for_byte_record<F>(
self,
terminator: u8,
for_each_record: F
) -> Result<(), Error> where
F: for<'_> FnMut(&[u8]) -> Result<bool, Error>,
Executes the given closure on each byte-terminated record in the underlying reader. Read more
impl<T> Downcast for T where
T: Any,
impl<T> Downcast for T where
T: Any,
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>ⓘNotable traits for Box<W, Global>impl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<F, A> Future for Box<F, A> where
F: Future + Unpin + ?Sized,
A: Allocator + 'static, type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>ⓘNotable traits for Box<W, Global>impl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<F, A> Future for Box<F, A> where
F: Future + Unpin + ?Sized,
A: Allocator + 'static, type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<F, A> Future for Box<F, A> where
F: Future + Unpin + ?Sized,
A: Allocator + 'static, type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
Convert Box<dyn Trait>
(where Trait: Downcast
) to Box<dyn Any>
. Box<dyn Any>
can
then be further downcast
into Box<ConcreteType>
where ConcreteType
implements Trait
. Read more
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
Convert Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
. Rc<Any>
can then be
further downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
. Read more
fn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
Convert &Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s. Read more
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
Convert &mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s. Read more
impl<A> DynCastExt for A
impl<A> DynCastExt for A
fn dyn_cast<T>(
self
) -> Result<<A as DynCastExtHelper<T>>::Target, <A as DynCastExtHelper<T>>::Source> where
A: DynCastExtHelper<T>,
T: ?Sized,
fn dyn_cast<T>(
self
) -> Result<<A as DynCastExtHelper<T>>::Target, <A as DynCastExtHelper<T>>::Source> where
A: DynCastExtHelper<T>,
T: ?Sized,
Use this to cast from one trait object type to another. Read more
fn dyn_upcast<T>(self) -> <A as DynCastExtAdvHelper<T, T>>::Target where
A: DynCastExtAdvHelper<T, T, Source = <A as DynCastExtAdvHelper<T, T>>::Target>,
T: ?Sized,
fn dyn_upcast<T>(self) -> <A as DynCastExtAdvHelper<T, T>>::Target where
A: DynCastExtAdvHelper<T, T, Source = <A as DynCastExtAdvHelper<T, T>>::Target>,
T: ?Sized,
Use this to upcast a trait to one of its supertraits. Read more
fn dyn_cast_adv<F, T>(
self
) -> Result<<A as DynCastExtAdvHelper<F, T>>::Target, <A as DynCastExtAdvHelper<F, T>>::Source> where
A: DynCastExtAdvHelper<F, T>,
F: ?Sized,
T: ?Sized,
fn dyn_cast_adv<F, T>(
self
) -> Result<<A as DynCastExtAdvHelper<F, T>>::Target, <A as DynCastExtAdvHelper<F, T>>::Source> where
A: DynCastExtAdvHelper<F, T>,
F: ?Sized,
T: ?Sized,
fn dyn_cast_with_config<C>(
self
) -> Result<<A as DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>>::Target, <A as DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>>::Source> where
C: DynCastConfig,
A: DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>,
fn dyn_cast_with_config<C>(
self
) -> Result<<A as DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>>::Target, <A as DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>>::Source> where
C: DynCastConfig,
A: DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>,
Use this to cast from one trait object type to another. With this method the type parameter is a config type that uniquely specifies which cast should be preformed. Read more
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
fn instrument(self, span: Span) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
T: Future, type Output = <T as Future>::Output;
sourcefn in_current_span(self) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
fn in_current_span(self) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
T: Future, type Output = <T as Future>::Output;
impl<R> ReadBytesExt for R where
R: Read + ?Sized,
impl<R> ReadBytesExt for R where
R: Read + ?Sized,
fn read_u8(&mut self) -> Result<u8, Error>
fn read_u8(&mut self) -> Result<u8, Error>
Reads an unsigned 8 bit integer from the underlying reader. Read more
fn read_i8(&mut self) -> Result<i8, Error>
fn read_i8(&mut self) -> Result<i8, Error>
Reads a signed 8 bit integer from the underlying reader. Read more
fn read_u16<T>(&mut self) -> Result<u16, Error> where
T: ByteOrder,
fn read_u16<T>(&mut self) -> Result<u16, Error> where
T: ByteOrder,
Reads an unsigned 16 bit integer from the underlying reader. Read more
fn read_i16<T>(&mut self) -> Result<i16, Error> where
T: ByteOrder,
fn read_i16<T>(&mut self) -> Result<i16, Error> where
T: ByteOrder,
Reads a signed 16 bit integer from the underlying reader. Read more
fn read_u24<T>(&mut self) -> Result<u32, Error> where
T: ByteOrder,
fn read_u24<T>(&mut self) -> Result<u32, Error> where
T: ByteOrder,
Reads an unsigned 24 bit integer from the underlying reader. Read more
fn read_i24<T>(&mut self) -> Result<i32, Error> where
T: ByteOrder,
fn read_i24<T>(&mut self) -> Result<i32, Error> where
T: ByteOrder,
Reads a signed 24 bit integer from the underlying reader. Read more
fn read_u32<T>(&mut self) -> Result<u32, Error> where
T: ByteOrder,
fn read_u32<T>(&mut self) -> Result<u32, Error> where
T: ByteOrder,
Reads an unsigned 32 bit integer from the underlying reader. Read more
fn read_i32<T>(&mut self) -> Result<i32, Error> where
T: ByteOrder,
fn read_i32<T>(&mut self) -> Result<i32, Error> where
T: ByteOrder,
Reads a signed 32 bit integer from the underlying reader. Read more
fn read_u48<T>(&mut self) -> Result<u64, Error> where
T: ByteOrder,
fn read_u48<T>(&mut self) -> Result<u64, Error> where
T: ByteOrder,
Reads an unsigned 48 bit integer from the underlying reader. Read more
fn read_i48<T>(&mut self) -> Result<i64, Error> where
T: ByteOrder,
fn read_i48<T>(&mut self) -> Result<i64, Error> where
T: ByteOrder,
Reads a signed 48 bit integer from the underlying reader. Read more
fn read_u64<T>(&mut self) -> Result<u64, Error> where
T: ByteOrder,
fn read_u64<T>(&mut self) -> Result<u64, Error> where
T: ByteOrder,
Reads an unsigned 64 bit integer from the underlying reader. Read more
fn read_i64<T>(&mut self) -> Result<i64, Error> where
T: ByteOrder,
fn read_i64<T>(&mut self) -> Result<i64, Error> where
T: ByteOrder,
Reads a signed 64 bit integer from the underlying reader. Read more
fn read_u128<T>(&mut self) -> Result<u128, Error> where
T: ByteOrder,
fn read_u128<T>(&mut self) -> Result<u128, Error> where
T: ByteOrder,
Reads an unsigned 128 bit integer from the underlying reader. Read more
fn read_i128<T>(&mut self) -> Result<i128, Error> where
T: ByteOrder,
fn read_i128<T>(&mut self) -> Result<i128, Error> where
T: ByteOrder,
Reads a signed 128 bit integer from the underlying reader. Read more
fn read_uint<T>(&mut self, nbytes: usize) -> Result<u64, Error> where
T: ByteOrder,
fn read_uint<T>(&mut self, nbytes: usize) -> Result<u64, Error> where
T: ByteOrder,
Reads an unsigned n-bytes integer from the underlying reader. Read more
fn read_int<T>(&mut self, nbytes: usize) -> Result<i64, Error> where
T: ByteOrder,
fn read_int<T>(&mut self, nbytes: usize) -> Result<i64, Error> where
T: ByteOrder,
Reads a signed n-bytes integer from the underlying reader. Read more
fn read_uint128<T>(&mut self, nbytes: usize) -> Result<u128, Error> where
T: ByteOrder,
fn read_uint128<T>(&mut self, nbytes: usize) -> Result<u128, Error> where
T: ByteOrder,
Reads an unsigned n-bytes integer from the underlying reader.
fn read_int128<T>(&mut self, nbytes: usize) -> Result<i128, Error> where
T: ByteOrder,
fn read_int128<T>(&mut self, nbytes: usize) -> Result<i128, Error> where
T: ByteOrder,
Reads a signed n-bytes integer from the underlying reader.
fn read_f32<T>(&mut self) -> Result<f32, Error> where
T: ByteOrder,
fn read_f32<T>(&mut self) -> Result<f32, Error> where
T: ByteOrder,
Reads a IEEE754 single-precision (4 bytes) floating point number from the underlying reader. Read more
fn read_f64<T>(&mut self) -> Result<f64, Error> where
T: ByteOrder,
fn read_f64<T>(&mut self) -> Result<f64, Error> where
T: ByteOrder,
Reads a IEEE754 double-precision (8 bytes) floating point number from the underlying reader. Read more
fn read_u16_into<T>(&mut self, dst: &mut [u16]) -> Result<(), Error> where
T: ByteOrder,
fn read_u16_into<T>(&mut self, dst: &mut [u16]) -> Result<(), Error> where
T: ByteOrder,
Reads a sequence of unsigned 16 bit integers from the underlying reader. Read more
fn read_u32_into<T>(&mut self, dst: &mut [u32]) -> Result<(), Error> where
T: ByteOrder,
fn read_u32_into<T>(&mut self, dst: &mut [u32]) -> Result<(), Error> where
T: ByteOrder,
Reads a sequence of unsigned 32 bit integers from the underlying reader. Read more
fn read_u64_into<T>(&mut self, dst: &mut [u64]) -> Result<(), Error> where
T: ByteOrder,
fn read_u64_into<T>(&mut self, dst: &mut [u64]) -> Result<(), Error> where
T: ByteOrder,
Reads a sequence of unsigned 64 bit integers from the underlying reader. Read more
fn read_u128_into<T>(&mut self, dst: &mut [u128]) -> Result<(), Error> where
T: ByteOrder,
fn read_u128_into<T>(&mut self, dst: &mut [u128]) -> Result<(), Error> where
T: ByteOrder,
Reads a sequence of unsigned 128 bit integers from the underlying reader. Read more
fn read_i8_into(&mut self, dst: &mut [i8]) -> Result<(), Error>
fn read_i8_into(&mut self, dst: &mut [i8]) -> Result<(), Error>
Reads a sequence of signed 8 bit integers from the underlying reader. Read more
fn read_i16_into<T>(&mut self, dst: &mut [i16]) -> Result<(), Error> where
T: ByteOrder,
fn read_i16_into<T>(&mut self, dst: &mut [i16]) -> Result<(), Error> where
T: ByteOrder,
Reads a sequence of signed 16 bit integers from the underlying reader. Read more
fn read_i32_into<T>(&mut self, dst: &mut [i32]) -> Result<(), Error> where
T: ByteOrder,
fn read_i32_into<T>(&mut self, dst: &mut [i32]) -> Result<(), Error> where
T: ByteOrder,
Reads a sequence of signed 32 bit integers from the underlying reader. Read more
fn read_i64_into<T>(&mut self, dst: &mut [i64]) -> Result<(), Error> where
T: ByteOrder,
fn read_i64_into<T>(&mut self, dst: &mut [i64]) -> Result<(), Error> where
T: ByteOrder,
Reads a sequence of signed 64 bit integers from the underlying reader. Read more
fn read_i128_into<T>(&mut self, dst: &mut [i128]) -> Result<(), Error> where
T: ByteOrder,
fn read_i128_into<T>(&mut self, dst: &mut [i128]) -> Result<(), Error> where
T: ByteOrder,
Reads a sequence of signed 128 bit integers from the underlying reader. Read more
fn read_f32_into<T>(&mut self, dst: &mut [f32]) -> Result<(), Error> where
T: ByteOrder,
fn read_f32_into<T>(&mut self, dst: &mut [f32]) -> Result<(), Error> where
T: ByteOrder,
Reads a sequence of IEEE754 single-precision (4 bytes) floating point numbers from the underlying reader. Read more
fn read_f32_into_unchecked<T>(&mut self, dst: &mut [f32]) -> Result<(), Error> where
T: ByteOrder,
fn read_f32_into_unchecked<T>(&mut self, dst: &mut [f32]) -> Result<(), Error> where
T: ByteOrder,
please use read_f32_into
instead
DEPRECATED. Read more
impl<R> ReadExt<R> for R where
R: Read,
impl<R> ReadExt<R> for R where
R: Read,
fn read_rmp<T>(&mut self) -> Result<T, PacketFrameReadError> where
T: DeserializeOwned,
R: Read,
impl<T> RmpRead for T where
T: Read,
impl<T> RmpRead for T where
T: Read,
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
fn vzip(self) -> V
sourceimpl<T> WithSubscriber for T
impl<T> WithSubscriber for T
sourcefn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
where
S: Into<Dispatch>,
fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
where
S: Into<Dispatch>,
T: Future, type Output = <T as Future>::Output;
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
sourcefn with_current_subscriber(self) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
fn with_current_subscriber(self) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
T: Future, type Output = <T as Future>::Output;
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more