This ERC20 contract implements a standard token with transfer, approval, and allowance functionalities. It also includes custom errors and emits events for transfers and approvals. Additionally, it supports EIP-2612 permit function for signed approvals.

The ERC1967Factory contract is a factory contract that allows for the deployment, upgrade, and administration of proxy contracts. It provides functions to change the admin of a proxy, upgrade the implementation of a proxy, and deploy new proxies. It also emits events for admin changes, upgrades, and deployments. The contract uses assembly code to interact with the proxy contracts and handle error conditions.

This smart contract is a library that provides various string operations, including converting numbers to strings, converting numbers to hexadecimal strings, and generating checksummed hexadecimal representations of addresses.

This contract allows multiple function calls to be executed in a single transaction using `DELEGATECALL`. It stores the results of each call and reverts the entire context if any call reverts. The function is non-payable to prevent double-spending. It efficiently returns the results and can be called internally at the end of a function that returns an array of bytes.

This smart contract is a library for parsing JSON strings. It provides functions to parse a JSON string and retrieve values, keys, and children of JSON items. It also supports various operations such as checking the type of an item, accessing the parent item, and parsing unsigned and signed integers from strings.

This contract implements an ownership functionality, allowing the owner to transfer ownership, renounce ownership, request a two-step ownership handover, cancel the handover, and complete the handover. It also includes custom error messages and emits events for ownership-related actions.

This smart contract implements the ERC2981 standard for royalty fees in NFTs. It allows setting and retrieving royalty information for tokens, including the receiver and amount. It also supports checking if the contract implements the ERC2981 interface.

This smart contract is a library that provides functions to encode and decode strings using the Base64 encoding scheme. It supports both standard and file-safe modes of encoding. The library allows developers to easily convert data to and from Base64 format.

This contract implements the EIP-712 standard for typed structured data hashing and signing. It provides functions to calculate the domain separator, hash typed data, and retrieve the EIP-712 domain information. The contract allows for caching of domain-related values to optimize gas costs.

This smart contract is a library that provides optimized sorting and other operations for sorted arrays. It includes functions for insertion sort and intro-quicksort algorithms, as well as operations like removing duplicates, searching for elements, and reversing the array. The contract supports sorting and operations on arrays of uint256, int256, and address types.