Macro select 

macro_rules! select {
    (@ {
        start=$start:expr;
        ( $($count:tt)* )
        $( ( $($skip:tt)* ) $bind:pat = $fut:expr, if $c:expr => $handle:expr, )+

        ; $else:expr

    }) => { ... };
    (@ { start=$start:expr; $($t:tt)* } ) => { ... };
    (@ { start=$start:expr; $($t:tt)* } else => $else:expr $(,)?) => { ... };
    (@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr, if $c:expr => $h:block, $($r:tt)* ) => { ... };
    (@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr => $h:block, $($r:tt)* ) => { ... };
    (@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr, if $c:expr => $h:block $($r:tt)* ) => { ... };
    (@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr => $h:block $($r:tt)* ) => { ... };
    (@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr, if $c:expr => $h:expr ) => { ... };
    (@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr => $h:expr ) => { ... };
    (@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr, if $c:expr => $h:expr, $($r:tt)* ) => { ... };
    (@ { start=$start:expr; ( $($s:tt)* ) $($t:tt)* } $p:pat = $f:expr => $h:expr, $($r:tt)* ) => { ... };
    (biased; $p:pat = $($t:tt)* ) => { ... };
    ( $p:pat = $($t:tt)* ) => { ... };
    () => { ... };
}