Please be aware that the behaviour of this operator changed from php5 to php7.

The following code will raise a Fatal error no matter what, and you wont be able to suppress it

<?php

function query()
{
    $myrs = null;
    $tmp = @$myrs->free_result();

    return $tmp;
}

var_dump(query());

echo "THIS IS NOT PRINT";
?>

more info at: http://bugs.php.net/bug.php?id=78532&thanks=3