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/// Waits on multiple concurrent branches, returning when the **first** branch
/// completes, cancelling the remaining branches.
///
/// The `select!` macro must be used inside of async functions, closures, and
/// blocks.
///
/// The `select!` macro accepts one or more branches with the following pattern:
///
/// ```text
/// <pattern> = <async expression> (, if <precondition>)? => <handler>,
/// ```
///
/// Additionally, the `select!` macro may include a single, optional `else`
/// branch, which evaluates if none of the other branches match their patterns:
///
/// ```text
/// else => <expression>
/// ```
///
/// The macro aggregates all `<async expression>` expressions and runs them
/// concurrently on the **current** task. Once the **first** expression
/// completes with a value that matches its `<pattern>`, the `select!` macro
/// returns the result of evaluating the completed branch's `<handler>`
/// expression.
///
/// Additionally, each branch may include an optional `if` precondition. If the
/// precondition returns `false`, then the branch is disabled. The provided
/// `<async expression>` is still evaluated but the resulting future is never
/// polled. This capability is useful when using `select!` within a loop.
///
/// The complete lifecycle of a `select!` expression is as follows:
///
/// 1. Evaluate all provided `<precondition>` expressions. If the precondition
/// returns `false`, disable the branch for the remainder of the current call
/// to `select!`. Re-entering `select!` due to a loop clears the "disabled"
/// state.
/// 2. Aggregate the `<async expression>`s from each branch, including the
/// disabled ones. If the branch is disabled, `<async expression>` is still
/// evaluated, but the resulting future is not polled.
/// 3. Concurrently await on the results for all remaining `<async expression>`s.
/// 4. Once an `<async expression>` returns a value, attempt to apply the value
/// to the provided `<pattern>`, if the pattern matches, evaluate `<handler>`
/// and return. If the pattern **does not** match, disable the current branch
/// and for the remainder of the current call to `select!`. Continue from step 3.
/// 5. If **all** branches are disabled, evaluate the `else` expression. If no
/// else branch is provided, panic.
///
/// # Runtime characteristics
///
/// By running all async expressions on the current task, the expressions are
/// able to run **concurrently** but not in **parallel**. This means all
/// expressions are run on the same thread and if one branch blocks the thread,
/// all other expressions will be unable to continue. If parallelism is
/// required, spawn each async expression using [`tokio::spawn`] and pass the
/// join handle to `select!`.
///
/// [`tokio::spawn`]: crate::spawn
///
/// # Fairness
///
/// By default, `select!` randomly picks a branch to check first. This provides
/// some level of fairness when calling `select!` in a loop with branches that
/// are always ready.
///
/// This behavior can be overridden by adding `biased;` to the beginning of the
/// macro usage. See the examples for details. This will cause `select` to poll
/// the futures in the order they appear from top to bottom. There are a few
/// reasons you may want this:
///
/// - The random number generation of `tokio::select!` has a non-zero CPU cost
/// - Your futures may interact in a way where known polling order is significant
///
/// But there is an important caveat to this mode. It becomes your responsibility
/// to ensure that the polling order of your futures is fair. If for example you
/// are selecting between a stream and a shutdown future, and the stream has a
/// huge volume of messages and zero or nearly zero time between them, you should
/// place the shutdown future earlier in the `select!` list to ensure that it is
/// always polled, and will not be ignored due to the stream being constantly
/// ready.
///
/// # Panics
///
/// The `select!` macro panics if all branches are disabled **and** there is no
/// provided `else` branch. A branch is disabled when the provided `if`
/// precondition returns `false` **or** when the pattern does not match the
/// result of `<async expression>`.
///
/// # Cancellation safety
///
/// When using `select!` in a loop to receive messages from multiple sources,
/// you should make sure that the receive call is cancellation safe to avoid
/// losing messages. This section goes through various common methods and
/// describes whether they are cancel safe. The lists in this section are not
/// exhaustive.
///
/// The following methods are cancellation safe:
///
/// * [`tokio::sync::mpsc::Receiver::recv`](crate::sync::mpsc::Receiver::recv)
/// * [`tokio::sync::mpsc::UnboundedReceiver::recv`](crate::sync::mpsc::UnboundedReceiver::recv)
/// * [`tokio::sync::broadcast::Receiver::recv`](crate::sync::broadcast::Receiver::recv)
/// * [`tokio::sync::watch::Receiver::changed`](crate::sync::watch::Receiver::changed)
/// * [`tokio::net::TcpListener::accept`](crate::net::TcpListener::accept)
/// * [`tokio::net::UnixListener::accept`](crate::net::UnixListener::accept)
/// * [`tokio::signal::unix::Signal::recv`](crate::signal::unix::Signal::recv)
/// * [`tokio::io::AsyncReadExt::read`](crate::io::AsyncReadExt::read) on any `AsyncRead`
/// * [`tokio::io::AsyncReadExt::read_buf`](crate::io::AsyncReadExt::read_buf) on any `AsyncRead`
/// * [`tokio::io::AsyncWriteExt::write`](crate::io::AsyncWriteExt::write) on any `AsyncWrite`
/// * [`tokio::io::AsyncWriteExt::write_buf`](crate::io::AsyncWriteExt::write_buf) on any `AsyncWrite`
/// * [`tokio_stream::StreamExt::next`](https://docs.rs/tokio-stream/0.1/tokio_stream/trait.StreamExt.html#method.next) on any `Stream`
/// * [`futures::stream::StreamExt::next`](https://docs.rs/futures/0.3/futures/stream/trait.StreamExt.html#method.next) on any `Stream`
///
/// The following methods are not cancellation safe and can lead to loss of data:
///
/// * [`tokio::io::AsyncReadExt::read_exact`](crate::io::AsyncReadExt::read_exact)
/// * [`tokio::io::AsyncReadExt::read_to_end`](crate::io::AsyncReadExt::read_to_end)
/// * [`tokio::io::AsyncReadExt::read_to_string`](crate::io::AsyncReadExt::read_to_string)
/// * [`tokio::io::AsyncWriteExt::write_all`](crate::io::AsyncWriteExt::write_all)
///
/// The following methods are not cancellation safe because they use a queue for
/// fairness and cancellation makes you lose your place in the queue:
///
/// * [`tokio::sync::Mutex::lock`](crate::sync::Mutex::lock)
/// * [`tokio::sync::RwLock::read`](crate::sync::RwLock::read)
/// * [`tokio::sync::RwLock::write`](crate::sync::RwLock::write)
/// * [`tokio::sync::Semaphore::acquire`](crate::sync::Semaphore::acquire)
/// * [`tokio::sync::Notify::notified`](crate::sync::Notify::notified)
///
/// To determine whether your own methods are cancellation safe, look for the
/// location of uses of `.await`. This is because when an asynchronous method is
/// cancelled, that always happens at an `.await`. If your function behaves
/// correctly even if it is restarted while waiting at an `.await`, then it is
/// cancellation safe.
///
/// Cancellation safety can be defined in the following way: If you have a
/// future that has not yet completed, then it must be a no-op to drop that
/// future and recreate it. This definition is motivated by the situation where
/// a `select!` is used in a loop. Without this guarantee, you would lose your
/// progress when another branch completes and you restart the `select!` by
/// going around the loop.
///
/// Be aware that cancelling something that is not cancellation safe is not
/// necessarily wrong. For example, if you are cancelling a task because the
/// application is shutting down, then you probably don't care that partially
/// read data is lost.
///
/// # Examples
///
/// Basic select with two branches.
///
/// ```
/// async fn do_stuff_async() {
/// // async work
/// }
///
/// async fn more_async_work() {
/// // more here
/// }
///
/// #[tokio::main]
/// async fn main() {
/// tokio::select! {
/// _ = do_stuff_async() => {
/// println!("do_stuff_async() completed first")
/// }
/// _ = more_async_work() => {
/// println!("more_async_work() completed first")
/// }
/// };
/// }
/// ```
///
/// Basic stream selecting.
///
/// ```
/// use tokio_stream::{self as stream, StreamExt};
///
/// #[tokio::main]
/// async fn main() {
/// let mut stream1 = stream::iter(vec![1, 2, 3]);
/// let mut stream2 = stream::iter(vec![4, 5, 6]);
///
/// let next = tokio::select! {
/// v = stream1.next() => v.unwrap(),
/// v = stream2.next() => v.unwrap(),
/// };
///
/// assert!(next == 1 || next == 4);
/// }
/// ```
///
/// Collect the contents of two streams. In this example, we rely on pattern
/// matching and the fact that `stream::iter` is "fused", i.e. once the stream
/// is complete, all calls to `next()` return `None`.
///
/// ```
/// use tokio_stream::{self as stream, StreamExt};
///
/// #[tokio::main]
/// async fn main() {
/// let mut stream1 = stream::iter(vec![1, 2, 3]);
/// let mut stream2 = stream::iter(vec![4, 5, 6]);
///
/// let mut values = vec![];
///
/// loop {
/// tokio::select! {
/// Some(v) = stream1.next() => values.push(v),
/// Some(v) = stream2.next() => values.push(v),
/// else => break,
/// }
/// }
///
/// values.sort();
/// assert_eq!(&[1, 2, 3, 4, 5, 6], &values[..]);
/// }
/// ```
///
/// Using the same future in multiple `select!` expressions can be done by passing
/// a reference to the future. Doing so requires the future to be [`Unpin`]. A
/// future can be made [`Unpin`] by either using [`Box::pin`] or stack pinning.
///
/// [`Unpin`]: std::marker::Unpin
/// [`Box::pin`]: std::boxed::Box::pin
///
/// Here, a stream is consumed for at most 1 second.
///
/// ```
/// use tokio_stream::{self as stream, StreamExt};
/// use tokio::time::{self, Duration};
///
/// #[tokio::main]
/// async fn main() {
/// let mut stream = stream::iter(vec![1, 2, 3]);
/// let sleep = time::sleep(Duration::from_secs(1));
/// tokio::pin!(sleep);
///
/// loop {
/// tokio::select! {
/// maybe_v = stream.next() => {
/// if let Some(v) = maybe_v {
/// println!("got = {}", v);
/// } else {
/// break;
/// }
/// }
/// _ = &mut sleep => {
/// println!("timeout");
/// break;
/// }
/// }
/// }
/// }
/// ```
///
/// Joining two values using `select!`.
///
/// ```
/// use tokio::sync::oneshot;
///
/// #[tokio::main]
/// async fn main() {
/// let (tx1, mut rx1) = oneshot::channel();
/// let (tx2, mut rx2) = oneshot::channel();
///
/// tokio::spawn(async move {
/// tx1.send("first").unwrap();
/// });
///
/// tokio::spawn(async move {
/// tx2.send("second").unwrap();
/// });
///
/// let mut a = None;
/// let mut b = None;
///
/// while a.is_none() || b.is_none() {
/// tokio::select! {
/// v1 = (&mut rx1), if a.is_none() => a = Some(v1.unwrap()),
/// v2 = (&mut rx2), if b.is_none() => b = Some(v2.unwrap()),
/// }
/// }
///
/// let res = (a.unwrap(), b.unwrap());
///
/// assert_eq!(res.0, "first");
/// assert_eq!(res.1, "second");
/// }
/// ```
///
/// Using the `biased;` mode to control polling order.
///
/// ```
/// #[tokio::main]
/// async fn main() {
/// let mut count = 0u8;
///
/// loop {
/// tokio::select! {
/// // If you run this example without `biased;`, the polling order is
/// // pseudo-random, and the assertions on the value of count will
/// // (probably) fail.
/// biased;
///
/// _ = async {}, if count < 1 => {
/// count += 1;
/// assert_eq!(count, 1);
/// }
/// _ = async {}, if count < 2 => {
/// count += 1;
/// assert_eq!(count, 2);
/// }
/// _ = async {}, if count < 3 => {
/// count += 1;
/// assert_eq!(count, 3);
/// }
/// _ = async {}, if count < 4 => {
/// count += 1;
/// assert_eq!(count, 4);
/// }
///
/// else => {
/// break;
/// }
/// };
/// }
/// }
/// ```
///
/// ## Avoid racy `if` preconditions
///
/// Given that `if` preconditions are used to disable `select!` branches, some
/// caution must be used to avoid missing values.
///
/// For example, here is **incorrect** usage of `sleep` with `if`. The objective
/// is to repeatedly run an asynchronous task for up to 50 milliseconds.
/// However, there is a potential for the `sleep` completion to be missed.
///
/// ```no_run,should_panic
/// use tokio::time::{self, Duration};
///
/// async fn some_async_work() {
/// // do work
/// }
///
/// #[tokio::main]
/// async fn main() {
/// let sleep = time::sleep(Duration::from_millis(50));
/// tokio::pin!(sleep);
///
/// while !sleep.is_elapsed() {
/// tokio::select! {
/// _ = &mut sleep, if !sleep.is_elapsed() => {
/// println!("operation timed out");
/// }
/// _ = some_async_work() => {
/// println!("operation completed");
/// }
/// }
/// }
///
/// panic!("This example shows how not to do it!");
/// }
/// ```
///
/// In the above example, `sleep.is_elapsed()` may return `true` even if
/// `sleep.poll()` never returned `Ready`. This opens up a potential race
/// condition where `sleep` expires between the `while !sleep.is_elapsed()`
/// check and the call to `select!` resulting in the `some_async_work()` call to
/// run uninterrupted despite the sleep having elapsed.
///
/// One way to write the above example without the race would be:
///
/// ```
/// use tokio::time::{self, Duration};
///
/// async fn some_async_work() {
/// # time::sleep(Duration::from_millis(10)).await;
/// // do work
/// }
///
/// #[tokio::main]
/// async fn main() {
/// let sleep = time::sleep(Duration::from_millis(50));
/// tokio::pin!(sleep);
///
/// loop {
/// tokio::select! {
/// _ = &mut sleep => {
/// println!("operation timed out");
/// break;
/// }
/// _ = some_async_work() => {
/// println!("operation completed");
/// }
/// }
/// }
/// }
/// ```
#[macro_export]
#[cfg_attr(docsrs, doc(cfg(feature = "macros")))]
macro_rules! select {
// Uses a declarative macro to do **most** of the work. While it is possible
// to implement fully with a declarative macro, a procedural macro is used
// to enable improved error messages.
//
// The macro is structured as a tt-muncher. All branches are processed and
// normalized. Once the input is normalized, it is passed to the top-most
// rule. When entering the macro, `@{ }` is inserted at the front. This is
// used to collect the normalized input.
//
// The macro only recurses once per branch. This allows using `select!`
// without requiring the user to increase the recursion limit.
// All input is normalized, now transform.
(@ {
// The index of the future to poll first (in bias mode), or the RNG
// expression to use to pick a future to poll first.
start=$start:expr;
// One `_` for each branch in the `select!` macro. Passing this to
// `count!` converts $skip to an integer.
( $($count:tt)* )
// Normalized select branches. `( $skip )` is a set of `_` characters.
// There is one `_` for each select branch **before** this one. Given
// that all input futures are stored in a tuple, $skip is useful for
// generating a pattern to reference the future for the current branch.
// $skip is also used as an argument to `count!`, returning the index of
// the current select branch.
$( ( $($skip:tt)* ) $bind:pat = $fut:expr, if $c:expr => $handle:expr, )+
// Fallback expression used when all select branches have been disabled.
; $else:expr
}) => {{
// Enter a context where stable "function-like" proc macros can be used.
//
// This module is defined within a scope and should not leak out of this
// macro.
#[doc(hidden)]
mod __tokio_select_util {
// Generate an enum with one variant per select branch
$crate::select_priv_declare_output_enum!( ( $($count)* ) );
}
// `tokio::macros::support` is a public, but doc(hidden) module
// including a re-export of all types needed by this macro.
use $crate::macros::support::Future;
use $crate::macros::support::Pin;
use $crate::macros::support::Poll::{Ready, Pending};
const BRANCHES: u32 = $crate::count!( $($count)* );
let mut disabled: __tokio_select_util::Mask = Default::default();
// First, invoke all the pre-conditions. For any that return true,
// set the appropriate bit in `disabled`.
$(
if !$c {
let mask: __tokio_select_util::Mask = 1 << $crate::count!( $($skip)* );
disabled |= mask;
}
)*
// Create a scope to separate polling from handling the output. This
// adds borrow checker flexibility when using the macro.
let mut output = {
// Safety: Nothing must be moved out of `futures`. This is to
// satisfy the requirement of `Pin::new_unchecked` called below.
//
// We can't use the `pin!` macro for this because `futures` is a
// tuple and the standard library provides no way to pin-project to
// the fields of a tuple.
let mut futures = ( $( $fut , )+ );
// This assignment makes sure that the `poll_fn` closure only has a
// reference to the futures, instead of taking ownership of them.
// This mitigates the issue described in
let mut futures = &mut futures;
$crate::macros::support::poll_fn(|cx| {
// Track if any branch returns pending. If no branch completes
// **or** returns pending, this implies that all branches are
// disabled.
let mut is_pending = false;
// Choose a starting index to begin polling the futures at. In
// practice, this will either be a pseudo-randomly generated
// number by default, or the constant 0 if `biased;` is
// supplied.
let start = $start;
for i in 0..BRANCHES {
let branch;
#[allow(clippy::modulo_one)]
{
branch = (start + i) % BRANCHES;
}
match branch {
$(
#[allow(unreachable_code)]
$crate::count!( $($skip)* ) => {
// First, if the future has previously been
// disabled, do not poll it again. This is done
// by checking the associated bit in the
// `disabled` bit field.
let mask = 1 << branch;
if disabled & mask == mask {
// The future has been disabled.
continue;
}
// Extract the future for this branch from the
// tuple
let ( $($skip,)* fut, .. ) = &mut *futures;
// Safety: future is stored on the stack above
// and never moved.
let mut fut = unsafe { Pin::new_unchecked(fut) };
// Try polling it
let out = match Future::poll(fut, cx) {
Ready(out) => out,
Pending => {
// Track that at least one future is
// still pending and continue polling.
is_pending = true;
continue;
}
};
// Disable the future from future polling.
disabled |= mask;
// The future returned a value, check if matches
// the specified pattern.
#[allow(unused_variables)]
#[allow(unused_mut)]
match &out {
$crate::select_priv_clean_pattern!($bind) => {}
_ => continue,
}
// The select is complete, return the value
return Ready($crate::select_variant!(__tokio_select_util::Out, ($($skip)*))(out));
}
)*
_ => unreachable!("reaching this means there probably is an off by one bug"),
}
}
if is_pending {
Pending
} else {
// All branches have been disabled.
Ready(__tokio_select_util::Out::Disabled)
}
}).await
};
match output {
$(
$crate::select_variant!(__tokio_select_util::Out, ($($skip)*) ($bind)) => $handle,
)*
__tokio_select_util::Out::Disabled => $else,
_ => unreachable!("failed to match bind"),
}
}};
// ==== Normalize =====
// These rules match a single `select!` branch and normalize it for
// processing by the first rule.
(@ { start=$start:expr; $($t:tt)* } ) => {
// No `else` branch
$crate::select!(@{ start=$start; $($t)*; panic!("all branches are disabled and there is no else branch") })
};
(@ { start=$start:expr; $($t:tt)* } else => $else:expr $(,)?) => {
$crate::select!(@{ start=$start; $($t)*; $else })
};
(@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr, if $c:expr => $h:block, $($r:tt)* ) => {
$crate::select!(@{ start=$start; ($($s)* _) $($t)* ($($s)*) $p = $f, if $c => $h, } $($r)*)
};
(@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr => $h:block, $($r:tt)* ) => {
$crate::select!(@{ start=$start; ($($s)* _) $($t)* ($($s)*) $p = $f, if true => $h, } $($r)*)
};
(@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr, if $c:expr => $h:block $($r:tt)* ) => {
$crate::select!(@{ start=$start; ($($s)* _) $($t)* ($($s)*) $p = $f, if $c => $h, } $($r)*)
};
(@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr => $h:block $($r:tt)* ) => {
$crate::select!(@{ start=$start; ($($s)* _) $($t)* ($($s)*) $p = $f, if true => $h, } $($r)*)
};
(@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr, if $c:expr => $h:expr ) => {
$crate::select!(@{ start=$start; ($($s)* _) $($t)* ($($s)*) $p = $f, if $c => $h, })
};
(@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr => $h:expr ) => {
$crate::select!(@{ start=$start; ($($s)* _) $($t)* ($($s)*) $p = $f, if true => $h, })
};
(@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr, if $c:expr => $h:expr, $($r:tt)* ) => {
$crate::select!(@{ start=$start; ($($s)* _) $($t)* ($($s)*) $p = $f, if $c => $h, } $($r)*)
};
(@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr => $h:expr, $($r:tt)* ) => {
$crate::select!(@{ start=$start; ($($s)* _) $($t)* ($($s)*) $p = $f, if true => $h, } $($r)*)
};
// ===== Entry point =====
(biased; $p:pat = $($t:tt)* ) => {
$crate::select!(@{ start=0; () } $p = $($t)*)
};
( $p:pat = $($t:tt)* ) => {
// Randomly generate a starting point. This makes `select!` a bit more
// fair and avoids always polling the first future.
$crate::select!(@{ start={ $crate::macros::support::thread_rng_n(BRANCHES) }; () } $p = $($t)*)
};
() => {
compile_error!("select! requires at least one branch.")
};
}
// And here... we manually list out matches for up to 64 branches... I'm not
// happy about it either, but this is how we manage to use a declarative macro!
#[macro_export]
#[doc(hidden)]
macro_rules! count {
() => {
0
};
(_) => {
1
};
(_ _) => {
2
};
(_ _ _) => {
3
};
(_ _ _ _) => {
4
};
(_ _ _ _ _) => {
5
};
(_ _ _ _ _ _) => {
6
};
(_ _ _ _ _ _ _) => {
7
};
(_ _ _ _ _ _ _ _) => {
8
};
(_ _ _ _ _ _ _ _ _) => {
9
};
(_ _ _ _ _ _ _ _ _ _) => {
10
};
(_ _ _ _ _ _ _ _ _ _ _) => {
11
};
(_ _ _ _ _ _ _ _ _ _ _ _) => {
12
};
(_ _ _ _ _ _ _ _ _ _ _ _ _) => {
13
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
14
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
15
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
16
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
17
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
18
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
19
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
20
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
21
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
22
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
23
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
24
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
25
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
26
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
27
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
28
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
29
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
30
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
31
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
32
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
33
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
34
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
35
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
36
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
37
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
38
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
39
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
40
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
41
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
42
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
43
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
44
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
45
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
46
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
47
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
48
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
49
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
50
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
51
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
52
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
53
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
54
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
55
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
56
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
57
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
58
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
59
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
60
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
61
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
62
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
63
};
(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) => {
64
};
}
#[macro_export]
#[doc(hidden)]
macro_rules! select_variant {
($($p:ident)::*, () $($t:tt)*) => {
$($p)::*::_0 $($t)*
};
($($p:ident)::*, (_) $($t:tt)*) => {
$($p)::*::_1 $($t)*
};
($($p:ident)::*, (_ _) $($t:tt)*) => {
$($p)::*::_2 $($t)*
};
($($p:ident)::*, (_ _ _) $($t:tt)*) => {
$($p)::*::_3 $($t)*
};
($($p:ident)::*, (_ _ _ _) $($t:tt)*) => {
$($p)::*::_4 $($t)*
};
($($p:ident)::*, (_ _ _ _ _) $($t:tt)*) => {
$($p)::*::_5 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_6 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_7 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_8 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_9 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_10 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_11 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_12 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_13 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_14 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_15 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_16 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_17 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_18 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_19 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_20 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_21 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_22 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_23 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_24 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_25 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_26 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_27 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_28 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_29 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_30 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_31 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_32 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_33 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_34 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_35 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_36 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_37 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_38 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_39 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_40 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_41 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_42 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_43 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_44 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_45 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_46 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_47 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_48 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_49 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_50 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_51 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_52 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_53 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_54 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_55 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_56 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_57 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_58 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_59 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_60 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_61 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_62 $($t)*
};
($($p:ident)::*, (_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _) $($t:tt)*) => {
$($p)::*::_63 $($t)*
};
}