Update documentation to mention _disableInitializer()

[ericglau]

Update https://docs.openzeppelin.com/upgrades-plugins/1.x/writing-upgradeable#initializing_the_implementation_contract to mention that when using Contracts v4.6.0 or later, the constructor should call _disableInitializers()

[Amxx]

Closed by #575

[taochen2001]

when adding the following to a upgradeable contract, it cannot be compiled by hardhat; Can you look into this? I got compilation error DeclarationError: Undeclared identifier. It seems compiler is not recognizing the function _disableInitializers().

constructor() {
       _disableInitializers();
    }

[ericglau]

@taochen2001 Which version of @openzeppelin/contracts-upgradeable are you using? _disableInitializers() was introduced in v4.6.0

[taochen2001]

Just checked, it is "version": "4.5.2". Shall I upgrade to v4.6.0? By the way, in the current 4.5.2 version, even if I imported the ReentrancyGuardUpgradeable.sol in my contract, nonReentrant modifier won't be recognized by the compiler (using Hardhat); not sure if this is a bug or not.

[taochen2001]

Now i upgraded to V4.6.0, but got the following error during compiling:
Error: Contract Token is not upgrade safe

contracts/Token.sol:12: Contract Token has a constructor
Define an initializer instead

[taochen2001]

It is now working after adding:
/// @Custom:oz-upgrades-unsafe-allow constructor

[gabkov]

the solution provided by @taochen2001 is the only one? seems like a workaround.

"@nomicfoundation/hardhat-toolbox": "^3.0.0",
"@openzeppelin/hardhat-upgrades": "^2.0.0",