ParserError: Expected primary expression - address payable - payable()

Question

I'm trying to get myself familiarized with ethereum. So I was going through a repo, and tried to rum the code :

function transferFundOnResolve(uint cid) private {
        // Could also be used: complainMap[cid]._status == Status.Resolved && 
        if(complainMap[cid]._reward > 0) {
            if(policeAccounts[complainSolver[cid]] != true) {
                complainSolver[cid].transfer( complainMap[cid]._reward );
                complainMap[cid]._reward = 0;
            }
            else {
                for(uint i=0; i<complainMap[cid]._contributors.length; i++) {
                    complainMap[cid]._contributors[i].transfer( complainMap[cid]._contAmount[i] );
                }
                complainMap[cid]._reward = 0;

            }
        }
    }

As it says TypeError: "send" and "transfer" are only available for objects of type "address payable", not "address".

So I modified and added payable() like :

function transferFundOnResolve(uint cid) private {
        // Could also be used: complainMap[cid]._status == Status.Resolved && 
        if(complainMap[cid]._reward > 0) {
            if(policeAccounts[complainSolver[cid]] != true) {
                complainSolver[cid].transfer( payable(complainMap[cid]._reward) );
                complainMap[cid]._reward = 0;
            }
            else {
                for(uint i=0; i<complainMap[cid]._contributors.length; i++) {
                    complainMap[cid]._contributors[i].transfer( payable(complainMap[cid]._contAmount[i]) );
                }
                complainMap[cid]._reward = 0;

            }
        }
    }

Now it says : ParserError: Expected primary expression.

How should I resolve this ?

I have pragma solidity ^0.5.16;

Answer 1

The reason you got that error because there is no function name payable that take an integer value and return payable address. The parser doesn't recognise it and give you an error like that.

I don't know your complainMap struct but i can guess that in it contain contrivutor variable and it's type is address. In solidity version greater than 0.5.0 they add payable address (you can see more at here: What's the difference between 'address' and 'address payable'?). The transfer function can only be use on address payable not address so the solution is to change the variable type of contributor from address to address payable or cast it to address payable.

Answer 2

Add this in your truffle-config.js

solc version: 0.6.0 and up will support payable(address)

module.exports = {
  // See <http://truffleframework.com/docs/advanced/configuration>
  // to customize your Truffle configuration!
  networks: {
    development: {
      host: "localhost",
      port: 7545,
      network_id: "5777",
      gas: 4600000
    }
  },
  compilers: {
    solc: {
      version: "0.6.0",    // Fetch exact version from solc-bin (default: truffle's version)
    }
  },
};

In your contract .sol use: pragma solidity ^0.6.0;