mea 0.6.4

A runtime-agnostic library providing essential synchronization primitives for asynchronous Rust programming.
Documentation 
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
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146

// Copyright 2024 tison <wander4096@gmail.com>
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::any::type_name;
use std::fmt;

/// An error returned when trying to send on a closed channel.
///
/// Returned from [`UnboundedSender::send`] or [`BoundedSender::send`] if the
/// corresponding [`UnboundedReceiver`] or [`BoundedReceiver`] has already been
/// dropped.
///
/// The message that could not be sent can be retrieved again with
/// [`SendError::into_inner`].
///
/// [`UnboundedSender::send`]: crate::mpsc::UnboundedSender::send
/// [`BoundedSender::send`]: crate::mpsc::BoundedSender::send
/// [`UnboundedReceiver`]: crate::mpsc::UnboundedReceiver
/// [`BoundedReceiver`]: crate::mpsc::BoundedReceiver
#[derive(Clone, PartialEq, Eq)]
pub struct SendError<T>(T);

impl<T> SendError<T> {
    /// Get a reference to the message that failed to be sent.
    pub fn as_inner(&self) -> &T {
        &self.0
    }

    /// Consumes the error and returns the message that failed to be sent.
    pub fn into_inner(self) -> T {
        self.0
    }

    /// Creates a new `SendError` with the given message.
    pub(super) fn new(msg: T) -> SendError<T> {
        SendError(msg)
    }
}

impl<T> fmt::Display for SendError<T> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.write_str("sending on a closed channel")
    }
}

impl<T> fmt::Debug for SendError<T> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "SendError<{}>(..)", type_name::<T>())
    }
}

impl<T> std::error::Error for SendError<T> {}

/// Error returned by `try_send`.
#[derive(Clone, PartialEq, Eq)]
pub enum TrySendError<T> {
    /// The channel is full, so data may not be sent at this time, but the receiver has not yet
    /// disconnected.
    Full(T),
    /// The receiver has become disconnected, and there will never be any more data sent on it.
    Disconnected(T),
}

impl<T> TrySendError<T> {
    /// Gets a reference to the message that failed to be sent.
    pub fn as_inner(&self) -> &T {
        match self {
            TrySendError::Full(msg) | TrySendError::Disconnected(msg) => msg,
        }
    }

    /// Consumes the error and returns the message that failed to be sent.
    pub fn into_inner(self) -> T {
        match self {
            TrySendError::Full(msg) | TrySendError::Disconnected(msg) => msg,
        }
    }
}

impl<T> fmt::Display for TrySendError<T> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.write_str(match self {
            TrySendError::Full(_) => "sending on a full channel",
            TrySendError::Disconnected(_) => "sending on a closed channel",
        })
    }
}

impl<T> fmt::Debug for TrySendError<T> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let ty = type_name::<T>();
        match self {
            TrySendError::Full(_) => write!(f, "TrySendError<{ty}>::Full(..)"),
            TrySendError::Disconnected(_) => write!(f, "TrySendError<{ty}>::Disconnected(..)"),
        }
    }
}

impl<T> std::error::Error for TrySendError<T> {}

/// Error returned by `recv`.
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum RecvError {
    /// The sender has become disconnected, and there will never be any more data received on it.
    Disconnected,
}

impl fmt::Display for RecvError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.write_str("receiving on a closed channel")
    }
}

impl std::error::Error for RecvError {}

/// Error returned by `try_recv`.
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum TryRecvError {
    /// This channel is currently empty, but the sender(s) have not yet disconnected, so data may
    /// yet become available.
    Empty,
    /// The sender has become disconnected, and there will never be any more data received on it.
    Disconnected,
}

impl fmt::Display for TryRecvError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.write_str(match self {
            TryRecvError::Empty => "receiving on an empty channel",
            TryRecvError::Disconnected => "receiving on a closed channel",
        })
    }
}

impl std::error::Error for TryRecvError {}