macro_rules! m {
	// a
	($expr :expr,  $( $func : ident    ) *   ) => {
		{
		let    x =    $expr;
									                $func (
														x
											)
	}
	};

				/* b */

   	()           => {/* c */};

		 				(@tag)   =>
						 {

						 };

// d
( $item:ident  ) =>      {
	mod macro_item    {  struct $item ; }
};
}

macro m2 {
	// a
	($expr :expr,  $( $func : ident    ) *   ) => {
		{
		let    x =    $expr;
									                $func (
														x
											)
	}
	}

				/* b */

   	()           => {/* c */}

		 				(@tag)   =>
						 {

						 }

// d
( $item:ident  ) =>      {
	mod macro_item    {  struct $item ; }
}
}

// #2439
macro_rules! m {
    (
        $line0_xxxxxxxxxxxxxxxxx: expr,
        $line1_xxxxxxxxxxxxxxxxx: expr,
        $line2_xxxxxxxxxxxxxxxxx: expr,
        $line3_xxxxxxxxxxxxxxxxx: expr,
    ) => {};
}