// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)pragmasolidity ^0.8.0;/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/abstractcontractContext{
function_msgSender() internalviewvirtualreturns (address) {
returnmsg.sender;
}
function_msgData() internalviewvirtualreturns (bytescalldata) {
returnmsg.data;
}
}
Contract Source Code
File 2 of 5: ERC20Relayer.sol
/**
* @title ERC20Relayer
* @author contact@erc-hub.com
* @notice ERC741 token standard, ERC20 & ERC721 synthetic token standard.
* Because it follows the logical rules of how it inherently works, it can take advantage of existing indexers.
* email: contact@erc-hub.com
* website: https://erc-hub.com
* github: https://github.com/erc-hub/ERC741
* twitter: https://twitter.com/ERC_Hub
* telegram: https://t.me/ERC_Hub
*/// SPDX-License-Identifier: MITpragmasolidity ^0.8.21;import"@openzeppelin/contracts/token/ERC20/IERC20.sol";
import"@openzeppelin/contracts/utils/Context.sol";
import"@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import"./ISemiFungibleERC741.sol";
contractERC20RelayerisIERC20, IERC20Metadata, Context{
ISemiFungibleERC741 public erc741;
modifieronlyNFT() {
require(
_msgSender() ==address(erc741),
"onlyNFT can call this function"
);
_;
}
constructor() {
erc741 = ISemiFungibleERC741(_msgSender());
}
functionname() externalviewoverridereturns (stringmemory) {
return erc741.name();
}
functionsymbol() externalviewoverridereturns (stringmemory) {
return erc741.symbol();
}
functiondecimals() externalviewoverridereturns (uint8) {
return erc741._decimals();
}
functiontotalSupply() externalviewoverridereturns (uint256) {
return erc741._erc20Supply();
}
functionbalanceOf(address account
) externalviewoverridereturns (uint256) {
return erc741.balanceOfERC20(account);
}
functiontransfer(address to,
uint256 amount
) externaloverridereturns (bool) {
bool status = erc741.transferERC20(_msgSender(), to, amount);
emit Transfer(_msgSender(), to, amount);
return status;
}
functionallowance(address owner,
address spender
) externalviewoverridereturns (uint256) {
return erc741.allowance(owner, spender);
}
functionapprove(address spender,
uint256 amount
) externaloverridereturns (bool) {
bool status = erc741.approveERC20(_msgSender(), spender, amount);
emit Approval(_msgSender(), spender, amount);
return status;
}
functiontransferFrom(addressfrom,
address to,
uint256 amount
) externaloverridereturns (bool) {
bool status = erc741.transferFromERC20(_msgSender(), from, to, amount);
emit Transfer(from, to, amount);
return status;
}
functionemitTransfer(addressfrom,
address to,
uint256 amount
) externalonlyNFT{
emit Transfer(from, to, amount);
}
}
Contract Source Code
File 3 of 5: IERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)pragmasolidity ^0.8.0;/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/interfaceIERC20{
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/eventTransfer(addressindexedfrom, addressindexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/eventApproval(addressindexed owner, addressindexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/functiontotalSupply() externalviewreturns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/functionbalanceOf(address account) externalviewreturns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/functiontransfer(address to, uint256 amount) externalreturns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/functionallowance(address owner, address spender) externalviewreturns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/functionapprove(address spender, uint256 amount) externalreturns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/functiontransferFrom(addressfrom, address to, uint256 amount) externalreturns (bool);
}
Contract Source Code
File 4 of 5: IERC20Metadata.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)pragmasolidity ^0.8.0;import"../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/interfaceIERC20MetadataisIERC20{
/**
* @dev Returns the name of the token.
*/functionname() externalviewreturns (stringmemory);
/**
* @dev Returns the symbol of the token.
*/functionsymbol() externalviewreturns (stringmemory);
/**
* @dev Returns the decimals places of the token.
*/functiondecimals() externalviewreturns (uint8);
}