Breaking Changes From Solidity 0.5.0

Solidity050Changes.sol

pragma solidity 0.5.0;

contract SolidityChanges {
    /**
     * https://solidity.readthedocs.io/en/v0.5.0/050-breaking-changes.html#semantic-and-syntactic-changes
     * 
     * The functions .call(), .delegatecall(), staticcall(), 
     * keccak256(), sha256() and ripemd160() now accept only 
     * a single bytes argument. Moreover, the argument is 
     * not padded. This was changed to make more explicit 
     * and clear how the arguments are concatenated. Change 
     * every .call() (and family) to a .call("") and every 
     * .call(signature, a, b, c) to use 
     * .call(abi.encodeWithSignature(signature, a, b, c)) 
     * (the last one only works for value types). Change every 
     * keccak256(a, b, c) to keccak256(abi.encodePacked(a, b, c)). 
     * Even though it is not a breaking change, it is suggested 
     * that developers change 
     * x.call(bytes4(keccak256("f(uint256)"), a, b) to 
     * x.call(abi.encodeWithSignature("f(uint256)", a, b)).
     * */
     function callTest(address otherContract) public{
         (bool success,) = otherContract.call(abi.encodeWithSignature("updateMyVar(uint256)",5));
         require(success);
     }
     
    /**
     * https://solidity.readthedocs.io/en/v0.5.0/050-breaking-changes.html#semantic-and-syntactic-changes
     * 
     * Functions .call(), .delegatecall() and .staticcall() now return (bool, bytes memory) 
     * to provide access to the return data. Change bool success = otherContract.call("f") 
     * to (bool success, bytes memory data) = otherContract.call("f").
     * */
     function callWithReturnTest(address otherContract) public returns(bytes memory){
         (bool success, bytes memory memoryData) = otherContract.call(abi.encodeWithSignature("updateWithReturn(uint256)",5));
         require(success);
         return memoryData;
     }
     
     /**
      * Explicit function visibility is now mandatory. Add public to every 
      * function and constructor, and external to every fallback or 
      * interface function that does not specify its visibility already.
      * */
     function () external {
         
     }
     
     
     /**
      * Explicit data location for all variables of struct, array or mapping 
      * types is now mandatory. This is also applied to function parameters 
      * and return variables. For example, change uint[] x = m_x to 
      * uint[] storage x = m_x, and 
      * function f(uint[][] x) to 
      * function f(uint[][] memory x) 
      * where memory is the data location and might be replaced by storage 
      * or calldata accordingly. Note that external functions require 
      * parameters with a data location of calldata.
      * */
      uint[] public myUint;
      function overwriteUintArray(uint[] memory _myUint) public {
          myUint = _myUint;
      }
      
      /**
       * Contract types do not include address members anymore in order to 
       * separate the namespaces. Therefore, it is now necessary to 
       * explicitly convert values of contract type to addresses before 
       * using an address member. Example: if c is a contract, 
       * change 
       * c.transfer(...) to 
       * address(c).transfer(...), and 
       * c.balance to 
       * address(c).balance.
       * */
       function getTheBalanceOf(OtherContract addressOtherContract) public view returns(uint) {
           return address(addressOtherContract).balance;
       }
       
       /**
        * The address type was split into address and address payable, where 
        * only address payable provides the transfer function. An address 
        * payable can be directly converted to an address, but the other 
        * way around is not allowed. Converting address to address payable is 
        * possible via conversion through uint160. If c is a contract, 
        * address(c) results in address payable only if c has a payable fallback 
        * function. If you use the withdraw pattern, you most likely do not 
        * have to change your code because transfer is only used on msg.sender 
        * instead of stored addresses and msg.sender is an address payable.
        * */
        function deposit() public payable {
            //we save the msg.value somewhere
        }
        function withdraw(address payable _receiver) public {
            _receiver.transfer(address(this).balance);
        }
        
        function destroyMe() public {
            selfdestruct(msg.sender);
        }
     
}

contract OtherContract {
    uint myVar;
    event CalledFunction(uint newVar);
    function updateMyVar(uint _someUint) public {
        myVar =_someUint;
        emit CalledFunction(_someUint);
    }
    
    
    function updateWithReturn(uint _someUint) public returns(uint){
        myVar =_someUint;
        emit CalledFunction(_someUint);
        return myVar;
    }
}