Easy method of returning or echoing strings on filters and actions

class.wp-filter-return.php

<?php

class WP_Filter_Return {
	private $val='';
	public function __construct( $val ) {
		$this->val = $val;
	}
	public function display() {
		echo $this->val;
	}
	public function return_val() {
		return $this->val;
	}
}

function wp_filter_return( $val ) {
	$obj = new WP_Filter_Return( $val );
	return array( $obj, 'return_val' );
}

function wp_filter_echo( $val ) {
	$obj = new WP_Filter_Return( $val );
	return array( $obj, 'display' );
}

example.php

<?php

// output a string in the pages header
add_action( 'wp_head', wp_filter_echo( 'Hello World!' ) );

// replace the current posts content with "Hello World!"
add_action( 'the_content', wp_filter_return( 'Hello World!' ) );