Solidity 0.6 breaking changes

A contract receiving Ether must have at least one of the functions below

• receive() external payable
• fallback() external payable

receive() is called if msg.data is empty, otherwise fallback() is called.

/*
    Which function is called, fallback() or receive()?

           send Ether
               |
         msg.data is empty?
              / \
            yes  no
            /     \
receive() exists?  fallback()
         /   \
        yes   no
        /      \
    receive()   fallback()
*/

TLDR: function() external payable is now splitted into receive() and fallback()

Destructible is no longer part of OpenZeppelin's contracts

Self-destructable contracts are open to being accidentally killed and should be used with tons of care because it's not always safe to use, so it shouldn't be as simple as inheriting a contract.

More in PR