Need a way to require multiple roles before assign one

Problem/Motivation

Currently we use the role mapping to assign Drupal roles, but we have a situation where we need to made sure than a user has a combination of roles before giving admin access.

I suggest using the pipeline character in the role mapping so it will be something like,

role1, role2, role3|role4

that will made any user with role 1 or role 2 or a combination of role 3 and 4 to get an admin role.