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
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
use core::convert;
use core::fmt;
use core::ops::{ControlFlow, FromResidual, Try};
use core::task::Poll;
#[unstable(feature = "ready_macro", issue = "70922")]
#[rustc_macro_transparency = "semitransparent"]
pub macro ready($e:expr) {
    match $e {
        $crate::task::Poll::Ready(t) => t,
        $crate::task::Poll::Pending => {
            return $crate::task::Poll::Pending;
        }
    }
}
#[unstable(feature = "poll_ready", issue = "89780")]
pub struct Ready<T>(pub(crate) Poll<T>);
#[unstable(feature = "poll_ready", issue = "89780")]
impl<T> Try for Ready<T> {
    type Output = T;
    type Residual = Ready<convert::Infallible>;
    #[inline]
    fn from_output(output: Self::Output) -> Self {
        Ready(Poll::Ready(output))
    }
    #[inline]
    fn branch(self) -> ControlFlow<Self::Residual, Self::Output> {
        match self.0 {
            Poll::Ready(v) => ControlFlow::Continue(v),
            Poll::Pending => ControlFlow::Break(Ready(Poll::Pending)),
        }
    }
}
#[unstable(feature = "poll_ready", issue = "89780")]
impl<T> FromResidual for Ready<T> {
    #[inline]
    fn from_residual(residual: Ready<convert::Infallible>) -> Self {
        match residual.0 {
            Poll::Pending => Ready(Poll::Pending),
        }
    }
}
#[unstable(feature = "poll_ready", issue = "89780")]
impl<T> FromResidual<Ready<convert::Infallible>> for Poll<T> {
    #[inline]
    fn from_residual(residual: Ready<convert::Infallible>) -> Self {
        match residual.0 {
            Poll::Pending => Poll::Pending,
        }
    }
}
#[unstable(feature = "poll_ready", issue = "89780")]
impl<T> fmt::Debug for Ready<T> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_tuple("Ready").finish()
    }
}