Updating ERC20 Contract from 0.4.0 to 0.6.0

Question

Im updating some ERC20 contact code from solidity 0.4.0 to 0.6.0 and hitting some snags as it seems openzeppeling has changed its structure since then as can be expected.

I cant access the balances variable from the ERC20 contract to update the owners balance in the contructor as the OZ ERC20 balances variable is now set to private as is the _totalSupply variable - how do I set these values in the parent OZ contracts or am I doing this all wrong

    pragma solidity <=0.6.0;


    import "openzeppelin-solidity/contracts/math/SafeMath.sol";
    import "openzeppelin-solidity/contracts/token/ERC20/ERC20.sol";

    contract Token is ERC20 {

        string public name = "test";
        string public symbol = "TST";
        uint8 public decimals = 18;
        uint256 public initSup = 1000;

        constructor() public {
            _totalSupply = initSup;
            balances[msg.sender] = initSup;
        }


    }

Answer 1

Figured it out.

Check the comments here relating to _mint() https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/contracts/token/ERC20/ERC20.sol

and also here: https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226

Starting with OpenZeppelin v2 this pattern is not only discouraged, but disallowed. The variables totalSupply and balances are now private implementation details of ERC20, and you can’t directly write to them. Instead, there is an internal _mint function that will do exactly this.