reveal.js – The HTML Presentation Framework

## Tech Talk
			Oct 12 '23<br/>
			[OpenZeppelin Contracts Release V5](https://github.com/OpenZeppelin/openzeppelin-contracts/releases/tag/v5.0.0)
			---
			## `$WHOAMI`
			* DeFi developer and Web3.0 Instructor.
			* Currently,
			  * Building $DINERO
			  * Blockchain Instructor at York University
			* Previously,  
			  * CTO and lead Blockchain Developer at opty.fi
			  * Adjunct Professor at George Brown College 
			---
			## New addition to V5
			* Modern best practices and namespace storages
			* Reduced gas consumption
			* Simplicity in codebase
			* Improving AccessManager
			* Test coverage is ~99% by adding fuzzing
			---
			## importing OZ V5
			```
			# Remix
			import "https://github.com/OpenZeppelin/openzeppelin-contracts/tree/v5.0.0/contracts"
			# foundry
			forge install forge install OpenZeppelin/openzeppelin-contracts@v5.0.0
			# Add @openzeppelin/contracts/=lib/openzeppelin-contracts/contracts/ in remappings.txt.
			# hardhat
			npm install @openzeppelin/contracts@v5.0.0
			```
			---
			## ERC20 hooks removal
			<img src="erc20-hooks.png" width="800">
			---
			## Ownable
			* Ownable now accepts a custom owner argument during construction, and Governor supports voting with bytes-formatted signatures and has Account Abstraction support by implementing ERC-1271.
			---
			## Removal
			* Address.isContract
			* Counters
			* SafeMath
			* SignedSafeMath
			* GovernorCompatibilityBravo
			* GovernorVotesComp
			* TokenTimelock (in favor of VestingWallet)
			* ERC777
			* All cross-chain contracts (including AccessControlCrossChain)
			---
			### Namespaced Storage for better upgrades security(ERC-7201)
			<img src="collision.png" width="500"><br/>
			Previously, upgradeable contracts used to have a `__gap` variable in storage between inherited contracts in order to reserve space for supporting new variables added between upgrades.
			---
			### scoping variables by namespace
			<img src="scoping.png" width="800">
			---
			## Custom Error and dynamic argument
			<img src="custom-error.png" width="900">
			---
			##  AccessManager
			* Make managing access control easier!
			  * Connect contract to an authority for access control
			  * Time-locked governance proposals
			  * Auth Utils Lib
			---
			<img src="access-control.png" width="800">
			---
			## Packing variables in storage
			<img src="packing.png" width="500">
			---
			## Account Abstraction 
			* Additional ERC-2771 and ERC-1967 support
			---
			## Utils libraries
			* Simplify handling nonces, ECDSA & Time
			---
			## Tooling update
			* Contract library integrated to work with OZ defender
			* Improved Upgrade plugin for hardhat, foundry in pipeline
			---
			## Gas optmization
			* Use custom error instead of revert string
			* Use immutable variable to save use of SLOAD instruction 
			---
			## Recommended Readings
			* [Openzeppelin Contracts V5 Release Notes](https://github.com/OpenZeppelin/openzeppelin-contracts/releases/tag/v5.0.0)
			* [OpenZeppelin Contract V5 blog](https://blog.openzeppelin.com/introducing-openzeppelin-contracts-5.0)