https://github.com/udacity/nd1309-work-code/blob/71b0da7d82fcb7320e307ca35d9dd0ea8322846a/Course_Identity_And_Smart_Contracts/Smart_Contracts_With_Solidity/structsContract.sol#L22 Without explicit conversion, the contract still compiles successfully, even in version >= 0.4. I'm wondering if there's something I'm missing.