title: NEAR and safe math on unsigned integers
body: <p>On Ethereum Solidity, a special library called <code>SafeMath</code> needs to be used when dealing with unsigned integer balance number. This is because of the <a href="https://ethereum.stackexchange.com/questions/8551/security-review-checklist-for-a-smart-contract">integer overflow exploits</a>.</p>
  <p>Does NEAR smart contracts written in Rust need similar mitigations? Or does Rust trap the oveflow automatically and panic?</p>