How do I add to a mapping that maps (address => bool)?

Question

This is just part of my contract, but shows where I create the mapping, the modifier onlyMember, and the function addMember. Basically, I want to be able to add new members who can execute onlyMember functions, as I - the owner - can. I was able to add a new member, as the owner, but when I switched to the member address and tried to execute other functions that appear later in the contract (which have the modifier onlyMember attached to them), I get an error. I am wondering if I set up the addMember function incorrectly, but remix isn't giving me any errors about it.

// <------------------------- MEMBERS ------------------------->

address owner = msg.sender;
bool ifmember;
mapping(address => bool) members;

modifier onlyMember {
    require(msg.sender == owner || members[msg.sender] == true);
    _;
    }

function addMember(address _address) public onlyMember {
    ifmember = members[_address];
    }

// <----------------------- END MEMBERS ----------------------->

Answer 1

There's nothing syntactically wrong with your addMember function so Remix won't give you any errors, but it's not really doing anything.

This line:

ifmember = members[_address];

is just setting the variable ifmember equal to the value of members[_address]. In the code you provided there's nothing changing the value of members[_address].

I'm not sure what ifmember is supposed to be doing, but I tihnk you want this for your addMember function:

function addMember(address _address) public onlyMember {
    members[_address] = true;
}