ChainID solidity version 0.6.12 - constructor

Question

I've seen this code working in many factory contracts:
constructor() public {
uint chainId;
assembly {
chainId := chainid
}
DOMAIN_SEPARATOR = keccak256(
abi.encode(
keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
keccak256(bytes(name)),
keccak256(bytes('1')),
chainId,
address(this)
)
);
}
However, this works when I use
pragma solidity =0.5.16;
But if I use pragma solidity =0.6.12;, I get an error:
ParseError: Expected '(' but got '}' } ^
I tried to do the following:
constructor() public {
uint chainId;
assembly {
chainId := chainid()
}...
But then I get multiple errors on variables and functions saying:
TypeError: overriding public state variable is missing string public constant name = ...
How do I write the assembly line in solidity version 0.6.12?
Thank you,
Using version 0.5.16 it's not an option because many imports use 0.6.12 and they won't work...

Answer 1

//SPDX-License-Identifier: MIT
pragma solidity =0.6.12;
contract Test {
string public constant name = "Your Contract name";
constructor() public {
uint chainId;
assembly {
chainId := chainid()
}
bytes32 DOMAIN_SEPARATOR;
DOMAIN_SEPARATOR = keccak256(
abi.encode(
keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
keccak256(bytes(name)),
keccak256(bytes('1')),
chainId,
address(this)
)
);}}
Try this. If you upgrade your code to version 0.8.0 and above there is a variable available in global namespace called
block.chainid