pragma solidity ^0.6.0; import "./ModifiersB.sol"; /** * New syntaxes in solc 0.6.x */ contract ModifiersC { uint counter; address owner; bool flag = true; constructor() public { owner = msg.sender; } modifier flippable { require(flag); _; } function flip() public { flag = !flag; } function simpleSetFlip(uint i) flippable public { counter = counter + i; } modifier onlyOwner { require(msg.sender == owner); _; } function set(uint i) onlyOwner public payable virtual { counter = counter + i; } }