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Breaking Changes From Solidity 0.5.0
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;
}
}
@YogeshPadsala

This comment has been minimized.

YogeshPadsala commented Dec 6, 2018

This was really helpful. Thank you :)

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