contract RBACMintableToken is MintableToken, RBAC {
  /**
   * A constant role name for indicating minters.
   */
  string public constant ROLE_MINTER = "minter";

  /**
   * @dev override the Mintable token modifier to add role based logic
   */
  modifier hasMintPermission() {
    checkRole(msg.sender, ROLE_MINTER);
    _;
  }

  /**
   * @dev add a minter role to an address
   * @param _minter address
   */
  function addMinter(address _minter) public onlyOwner {
    addRole(_minter, ROLE_MINTER);
  }

  /**
   * @dev remove a minter role from an address
   * @param _minter address
   */
  function removeMinter(address _minter) public onlyOwner {
    removeRole(_minter, ROLE_MINTER);
  }
}
/**
 * @title RBACMintableToken
 * @author Vittorio Minacori (@vittominacori)
 * @dev Mintable Token, with RBAC minter permissions
 */
function addMinter(address _minter) public onlyOwner {
    addRole(_minter, ROLE_MINTER);
  }
/**
 * @dev add a minter role to an address
 * @param _minter address
 */