Macro proconio::input

macro_rules! input {
    (@from [$source:expr] @rest) => { ... };
    (@from [$source:expr] @rest mut $($rest:tt)*) => { ... };
    (@from [$source:expr] @rest $($rest:tt)*) => { ... };
    (@from [$source:expr] @mut [$($mut:tt)?] @rest $var:tt: $($rest:tt)*) => { ... };
    (@from [$source:expr] @mut [$($mut:tt)?] @var $var:tt @kind [$($kind:tt)*] @rest) => { ... };
    (@from [$source:expr] @mut [$($mut:tt)?] @var $var:tt @kind [$($kind:tt)*] @rest, $($rest:tt)*) => { ... };
    (@from [$source:expr] @mut [$($mut:tt)?] @var $var:tt @kind [$($kind:tt)*] @rest $tt:tt $($rest:tt)*) => { ... };
    (from $source:expr, $($rest:tt)*) => { ... };
    ($($rest:tt)*) => { ... };
}

read input from stdin.

basic syntax is:

input! {
    from source,          // optional: if you omitted, stdin is used by default.
    (mut) variable: type, // mut is optional: mut makes the variable mutable.
    ...
}

the trailing comma is optional. source can be anything implementing Source. This macro moves out the specified source. If you want to prevent moving, you can use &mut source since &mut S where S: Source also implements Source.