Convert value from specific multidimensional array key into key in new array with original arrays as value

Basically I just would like to know if there is a built-in way of doing this, that might be faster, like maybe with an array_map callback or something:

function array_rekey($a, $column)
{
    $array = array();
    foreach($a as $keys) $array[$keys[$column]] = $keys;
    return $array;
}