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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
/// Prints to the standard output.
///
/// Equivalent to the [`println!`] macro except that a newline is not printed at
/// the end of the message.
///
/// Note that stdout is frequently line-buffered by default so it may be
/// necessary to use [`io::stdout().flush()`][flush] to ensure the output is emitted
/// immediately.
///
/// Use `print!` only for the primary output of your program. Use
/// [`eprint!`] instead to print error and progress messages.
///
/// [`println!`]: macro.println.html
/// [flush]: io/trait.Write.html#tymethod.flush
/// [`eprint!`]: macro.eprint.html
///
/// # Panics
///
/// Panics if writing to `io::stdout()` fails.
///
/// # Examples
///
/// ```
/// # async_std::task::block_on(async {
/// #
/// use async_std::io;
/// use async_std::prelude::*;
/// use async_std::print;
///
/// print!("this ").await;
/// print!("will ").await;
/// print!("be ").await;
/// print!("on ").await;
/// print!("the ").await;
/// print!("same ").await;
/// print!("line ").await;
///
/// io::stdout().flush().await.unwrap();
///
/// print!("this string has a newline, why not choose println! instead?\n").await;
///
/// io::stdout().flush().await.unwrap();
/// #
/// # })
/// ```
#[cfg(feature = "unstable")]
#[cfg_attr(feature = "docs", doc(cfg(unstable)))]
#[macro_export]
macro_rules! print {
    ($($arg:tt)*) => ($crate::io::_print(format_args!($($arg)*)))
}

/// Prints to the standard output, with a newline.
///
/// On all platforms, the newline is the LINE FEED character (`\n`/`U+000A`) alone
/// (no additional CARRIAGE RETURN (`\r`/`U+000D`)).
///
/// Use the [`format!`] syntax to write data to the standard output.
/// See [`std::fmt`] for more information.
///
/// Use `println!` only for the primary output of your program. Use
/// [`eprintln!`] instead to print error and progress messages.
///
/// [`format!`]: macro.format.html
/// [`std::fmt`]: https://doc.rust-lang.org/std/fmt/index.html
/// [`eprintln!`]: macro.eprintln.html
/// # Panics
///
/// Panics if writing to `io::stdout` fails.
///
/// # Examples
///
/// ```
/// # async_std::task::block_on(async {
/// #
/// use async_std::println;
///
/// println!().await; // prints just a newline
/// println!("hello there!").await;
/// println!("format {} arguments", "some").await;
/// #
/// # })
/// ```
#[cfg(feature = "unstable")]
#[cfg_attr(feature = "docs", doc(cfg(unstable)))]
#[macro_export]
macro_rules! println {
    () => ($crate::print!("\n"));
    ($($arg:tt)*) => (async {
        $crate::io::_print(format_args!($($arg)*)).await;
        $crate::io::_print(format_args!("\n")).await;
    })
}

/// Prints to the standard error.
///
/// Equivalent to the [`print!`] macro, except that output goes to
/// [`io::stderr`] instead of `io::stdout`. See [`print!`] for
/// example usage.
///
/// Use `eprint!` only for error and progress messages. Use `print!`
/// instead for the primary output of your program.
///
/// [`io::stderr`]: io/struct.Stderr.html
/// [`print!`]: macro.print.html
///
/// # Panics
///
/// Panics if writing to `io::stderr` fails.
///
/// # Examples
///
/// ```
/// # async_std::task::block_on(async {
/// #
/// use async_std::eprint;
///
/// eprint!("Error: Could not complete task").await;
/// #
/// # })
/// ```
#[cfg(feature = "unstable")]
#[cfg_attr(feature = "docs", doc(cfg(unstable)))]
#[macro_export]
macro_rules! eprint {
    ($($arg:tt)*) => ($crate::io::_eprint(format_args!($($arg)*)))
}

/// Prints to the standard error, with a newline.
///
/// Equivalent to the [`println!`] macro, except that output goes to
/// [`io::stderr`] instead of `io::stdout`. See [`println!`] for
/// example usage.
///
/// Use `eprintln!` only for error and progress messages. Use `println!`
/// instead for the primary output of your program.
///
/// [`io::stderr`]: io/struct.Stderr.html
/// [`println!`]: macro.println.html
///
/// # Panics
///
/// Panics if writing to `io::stderr` fails.
///
/// # Examples
///
/// ```
/// # async_std::task::block_on(async {
/// #
/// use async_std::eprintln;
///
/// eprintln!("Error: Could not complete task").await;
/// #
/// # })
/// ```
#[cfg(feature = "unstable")]
#[cfg_attr(feature = "docs", doc(cfg(unstable)))]
#[macro_export]
macro_rules! eprintln {
    () => (async { $crate::eprint!("\n").await; });
    ($($arg:tt)*) => (
        async {
            $crate::io::_eprint(format_args!($($arg)*)).await;
            $crate::io::_eprint(format_args!("\n")).await;
        }
    );
}

/// Declares task-local values.
///
/// The macro wraps any number of static declarations and makes them task-local. Attributes and
/// visibility modifiers are allowed.
///
/// Each declared value is of the accessor type [`LocalKey`].
///
/// [`LocalKey`]: task/struct.LocalKey.html
///
/// # Examples
///
/// ```
/// #
/// use std::cell::Cell;
///
/// use async_std::prelude::*;
/// use async_std::task;
///
/// task_local! {
///     static VAL: Cell<u32> = Cell::new(5);
/// }
///
/// task::block_on(async {
///     let v = VAL.with(|c| c.get());
///     assert_eq!(v, 5);
/// });
/// ```
#[cfg(feature = "default")]
#[macro_export]
macro_rules! task_local {
    () => ();

    ($(#[$attr:meta])* $vis:vis static $name:ident: $t:ty = $init:expr) => (
        $(#[$attr])* $vis static $name: $crate::task::LocalKey<$t> = {
            #[inline]
            fn __init() -> $t {
                $init
            }

            $crate::task::LocalKey {
                __init,
                __key: ::std::sync::atomic::AtomicU32::new(0),
            }
        };
    );

    ($(#[$attr:meta])* $vis:vis static $name:ident: $t:ty = $init:expr; $($rest:tt)*) => (
        $crate::task_local!($(#[$attr])* $vis static $name: $t = $init);
        $crate::task_local!($($rest)*);
    );
}