What is the has() function in Solidity?

Question

What is the has() function in Solidity?

  struct Role {
    mapping (address => bool) bearer;
  }

  function add(Role storage role, address account) internal {
    require(account != address(0), "The account cannot be an uninitialized address");
    require(!has(role, account)); // right here

    role.bearer[account] = true;
  }

Intuitively, I think it's determining whether the account exists in role or not and returning a boolean value, but can't seem to find the documentation.

Answer 1

It's not part of Solidity, you are probable inheriting from the access control in the OpenZeppelin contracts: https://docs.openzeppelin.com/contracts/2.x/api/access#Roles-has-struct-Roles-Role-address-. In v3 it's called hasRole.

See full documentation at: https://docs.openzeppelin.com/contracts/2.x/access-control#using-roles.