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cNoveron/1_Storage.sol

Created October 21, 2020 06:45
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Created using remix-ide: Realtime Ethereum Contract Compiler and Runtime. Load this file by pasting this gists URL or ID at https://remix.ethereum.org/#version=soljson-v0.6.6+commit.6c089d02.js&optimize=false&gist=
Raw
1_Storage.sol
pragma solidity >=0.4.22 <0.7.0;
/**
* @title Storage
* @dev Store & retrieve value in a variable
*/
contract Storage {
uint256 number;
/**
* @dev Store value in variable
* @param num value to store
*/
function store(uint256 num) public {
number = num;
}
/**
* @dev Return value
* @return value of 'number'
*/
function retrieve() public view returns (uint256){
return number;
}
}
Raw
2_Owner.sol
pragma solidity >=0.4.22 <0.7.0;
/**
* @title Owner
* @dev Set & change owner
*/
contract Owner {
address private owner;
// event for EVM logging
event OwnerSet(address indexed oldOwner, address indexed newOwner);
// modifier to check if caller is owner
modifier isOwner() {
// If the first argument of 'require' evaluates to 'false', execution terminates and all
// changes to the state and to Ether balances are reverted.
// This used to consume all gas in old EVM versions, but not anymore.
// It is often a good idea to use 'require' to check if functions are called correctly.
// As a second argument, you can also provide an explanation about what went wrong.
require(msg.sender == owner, "Caller is not owner");
_;
}
/**
* @dev Set contract deployer as owner
*/
constructor() public {
owner = msg.sender; // 'msg.sender' is sender of current call, contract deployer for a constructor
emit OwnerSet(address(0), owner);
}
/**
* @dev Change owner
* @param newOwner address of new owner
*/
function changeOwner(address newOwner) public isOwner {
emit OwnerSet(owner, newOwner);
owner = newOwner;
}
/**
* @dev Return owner address
* @return address of owner
*/
function getOwner() external view returns (address) {
return owner;
}
}
Raw
3_Ballot.sol
pragma solidity >=0.4.22 <0.7.0;
/**
* @title Ballot
* @dev Implements voting process along with vote delegation
*/
contract Ballot {
struct Voter {
uint weight; // weight is accumulated by delegation
bool voted; // if true, that person already voted
address delegate; // person delegated to
uint vote; // index of the voted proposal
}
struct Proposal {
// If you can limit the length to a certain number of bytes,
// always use one of bytes1 to bytes32 because they are much cheaper
bytes32 name; // short name (up to 32 bytes)
uint voteCount; // number of accumulated votes
}
address public chairperson;
mapping(address => Voter) public voters;
Proposal[] public proposals;
/**
* @dev Create a new ballot to choose one of 'proposalNames'.
* @param proposalNames names of proposals
*/
constructor(bytes32[] memory proposalNames) public {
chairperson = msg.sender;
voters[chairperson].weight = 1;
for (uint i = 0; i < proposalNames.length; i++) {
// 'Proposal({...})' creates a temporary
// Proposal object and 'proposals.push(...)'
// appends it to the end of 'proposals'.
proposals.push(Proposal({
name: proposalNames[i],
voteCount: 0
}));
}
}
/**
* @dev Give 'voter' the right to vote on this ballot. May only be called by 'chairperson'.
* @param voter address of voter
*/
function giveRightToVote(address voter) public {
require(
msg.sender == chairperson,
"Only chairperson can give right to vote."
);
require(
!voters[voter].voted,
"The voter already voted."
);
require(voters[voter].weight == 0);
voters[voter].weight = 1;
}
/**
* @dev Delegate your vote to the voter 'to'.
* @param to address to which vote is delegated
*/
function delegate(address to) public {
Voter storage sender = voters[msg.sender];
require(!sender.voted, "You already voted.");
require(to != msg.sender, "Self-delegation is disallowed.");
while (voters[to].delegate != address(0)) {
to = voters[to].delegate;
// We found a loop in the delegation, not allowed.
require(to != msg.sender, "Found loop in delegation.");
}
sender.voted = true;
sender.delegate = to;
Voter storage delegate_ = voters[to];
if (delegate_.voted) {
// If the delegate already voted,
// directly add to the number of votes
proposals[delegate_.vote].voteCount += sender.weight;
} else {
// If the delegate did not vote yet,
// add to her weight.
delegate_.weight += sender.weight;
}
}
/**
* @dev Give your vote (including votes delegated to you) to proposal 'proposals[proposal].name'.
* @param proposal index of proposal in the proposals array
*/
function vote(uint proposal) public {
Voter storage sender = voters[msg.sender];
require(sender.weight != 0, "Has no right to vote");
require(!sender.voted, "Already voted.");
sender.voted = true;
sender.vote = proposal;
// If 'proposal' is out of the range of the array,
// this will throw automatically and revert all
// changes.
proposals[proposal].voteCount += sender.weight;
}
/**
* @dev Computes the winning proposal taking all previous votes into account.
* @return winningProposal_ index of winning proposal in the proposals array
*/
function winningProposal() public view
returns (uint winningProposal_)
{
uint winningVoteCount = 0;
for (uint p = 0; p < proposals.length; p++) {
if (proposals[p].voteCount > winningVoteCount) {
winningVoteCount = proposals[p].voteCount;
winningProposal_ = p;
}
}
}
/**
* @dev Calls winningProposal() function to get the index of the winner contained in the proposals array and then
* @return winnerName_ the name of the winner
*/
function winnerName() public view
returns (bytes32 winnerName_)
{
winnerName_ = proposals[winningProposal()].name;
}
}
Raw
IEther.sol
// File: @openzeppelin\contracts\token\ERC20\IERC20.sol
pragma solidity ^0.5.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP. Does not include
* the optional functions; to access them see {ERC20Detailed}.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount)
external
returns (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.
*/
function allowance(address owner, address spender)
external
view
returns (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.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` 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.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed 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.
*/
event Approval(
address indexed owner,
address indexed spender,
uint256 value
);
}
// File: @openzeppelin\contracts\GSN\Context.sol
pragma solidity ^0.5.0;
/*
* @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 GSN 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.
*/
contract Context {
// Empty internal constructor, to prevent people from mistakenly deploying
// an instance of this contract, which should be used via inheritance.
constructor() internal {}
// solhint-disable-previous-line no-empty-blocks
function _msgSender() internal view returns (address payable) {
return msg.sender;
}
function _msgData() internal view returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
// File: @openzeppelin\contracts\token\ERC20\ERC20.sol
pragma solidity ^0.5.0;
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20Mintable}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin guidelines: functions revert instead
* of returning `false` on failure. This behavior is nonetheless conventional
* and does not conflict with the expectations of ERC20 applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20 {
using SafeMath for uint256;
mapping(address => uint256) _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 _totalSupply;
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender)
public
view
returns (uint256)
{
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20};
*
* Requirements:
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for `sender`'s tokens of at least
* `amount`.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) public returns (bool) {
_transfer(sender, recipient, amount);
_approve(
sender,
_msgSender(),
_allowances[sender][_msgSender()].sub(
amount,
"ERC20: transfer amount exceeds allowance"
)
);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue)
public
returns (bool)
{
_approve(
_msgSender(),
spender,
_allowances[_msgSender()][spender].add(addedValue)
);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue)
public
returns (bool)
{
_approve(
_msgSender(),
spender,
_allowances[_msgSender()][spender].sub(
subtractedValue,
"ERC20: decreased allowance below zero"
)
);
return true;
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(
address sender,
address recipient,
uint256 amount
) internal {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_balances[sender] = _balances[sender].sub(
amount,
"ERC20: transfer amount exceeds balance"
);
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements
*
* - `to` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal {
require(account != address(0), "ERC20: mint to the zero address");
_totalSupply = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal {
require(account != address(0), "ERC20: burn from the zero address");
_balances[account] = _balances[account].sub(
amount,
"ERC20: burn amount exceeds balance"
);
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
*
* This is internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(
address owner,
address spender,
uint256 amount
) internal {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Destroys `amount` tokens from `account`.`amount` is then deducted
* from the caller's allowance.
*
* See {_burn} and {_approve}.
*/
function _burnFrom(address account, uint256 amount) internal {
_burn(account, amount);
_approve(
account,
_msgSender(),
_allowances[account][_msgSender()].sub(
amount,
"ERC20: burn amount exceeds allowance"
)
);
}
}
// File: @openzeppelin\contracts\token\ERC20\ERC20Detailed.sol
pragma solidity ^0.5.0;
/**
* @dev Optional functions from the ERC20 standard.
*/
contract ERC20Detailed is IERC20 {
string private _name;
string private _symbol;
uint8 private _decimals;
/**
* @dev Sets the values for `name`, `symbol`, and `decimals`. All three of
* these values are immutable: they can only be set once during
* construction.
*/
constructor(
string memory name,
string memory symbol,
uint8 decimals
) public {
_name = name;
_symbol = symbol;
_decimals = decimals;
}
/**
* @dev Returns the name of the token.
*/
function name() public view returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5,05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view returns (uint8) {
return _decimals;
}
}
// File: @openzeppelin\contracts\utils\ReentrancyGuard.sol
pragma solidity ^0.5.0;
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*/
contract ReentrancyGuard {
// counter to allow mutex lock with only one SSTORE operation
uint256 private _guardCounter;
constructor() internal {
// The counter starts at one to prevent changing it from zero to a non-zero
// value, which is a more expensive operation.
_guardCounter = 1;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and make it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
_guardCounter += 1;
uint256 localCounter = _guardCounter;
_;
require(
localCounter == _guardCounter,
"ReentrancyGuard: reentrant call"
);
}
}
// File: @openzeppelin\contracts\ownership\Ownable.sol
pragma solidity ^0.5.0;
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
contract Ownable is Context {
address private _owner;
event OwnershipTransferred(
address indexed previousOwner,
address indexed newOwner
);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() internal {
_owner = _msgSender();
emit OwnershipTransferred(address(0), _owner);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(isOwner(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Returns true if the caller is the current owner.
*/
function isOwner() public view returns (bool) {
return _msgSender() == _owner;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public onlyOwner {
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
*/
function _transferOwnership(address newOwner) internal {
require(
newOwner != address(0),
"Ownable: new owner is the zero address"
);
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
// File: @openzeppelin\contracts\math\SafeMath.sol
pragma solidity ^0.5.0;
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot overflow.
*
* _Available since v2.4.0._
*/
function sub(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*
* _Available since v2.4.0._
*/
function div(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*
* _Available since v2.4.0._
*/
function mod(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
// File: node_modules\@openzeppelin\contracts\utils\Address.sol
pragma solidity ^0.5.5;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* This test is non-exhaustive, and there may be false-negatives: during the
* execution of a contract's constructor, its address will be reported as
* not containing a contract.
*
* IMPORTANT: It is unsafe to assume that an address for which this
* function returns false is an externally-owned account (EOA) and not a
* contract.
*/
function isContract(address account) internal view returns (bool) {
// This method relies in extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
// for accounts without code, i.e. `keccak256('')`
bytes32 codehash;
bytes32 accountHash
= 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
// solhint-disable-next-line no-inline-assembly
assembly {
codehash := extcodehash(account)
}
return (codehash != 0x0 && codehash != accountHash);
}
/**
* @dev Converts an `address` into `address payable`. Note that this is
* simply a type cast: the actual underlying value is not changed.
*
* _Available since v2.4.0._
*/
function toPayable(address account)
internal
pure
returns (address payable)
{
return address(uint160(account));
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*
* _Available since v2.4.0._
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(
address(this).balance >= amount,
"Address: insufficient balance"
);
// solhint-disable-next-line avoid-call-value
(bool success, ) = recipient.call.value(amount)("");
require(
success,
"Address: unable to send value, recipient may have reverted"
);
}
}
// File: @openzeppelin\contracts\token\ERC20\SafeERC20.sol
pragma solidity ^0.5.0;
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using SafeMath for uint256;
using Address for address;
function safeTransfer(
IERC20 token,
address to,
uint256 value
) internal {
callOptionalReturn(
token,
abi.encodeWithSelector(token.transfer.selector, to, value)
);
}
function safeTransferFrom(
IERC20 token,
address from,
address to,
uint256 value
) internal {
callOptionalReturn(
token,
abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
);
}
function safeApprove(
IERC20 token,
address spender,
uint256 value
) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
// solhint-disable-next-line max-line-length
require(
(value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
callOptionalReturn(
token,
abi.encodeWithSelector(token.approve.selector, spender, value)
);
}
function safeIncreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
uint256 newAllowance = token.allowance(address(this), spender).add(
value
);
callOptionalReturn(
token,
abi.encodeWithSelector(
token.approve.selector,
spender,
newAllowance
)
);
}
function safeDecreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(
value,
"SafeERC20: decreased allowance below zero"
);
callOptionalReturn(
token,
abi.encodeWithSelector(
token.approve.selector,
spender,
newAllowance
)
);
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves.
// A Solidity high level call has three parts:
// 1. The target address is checked to verify it contains contract code
// 2. The call itself is made, and success asserted
// 3. The return value is decoded, which in turn checks the size of the returned data.
// solhint-disable-next-line max-line-length
require(address(token).isContract(), "SafeERC20: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = address(token).call(data);
require(success, "SafeERC20: low-level call failed");
if (returndata.length > 0) {
// Return data is optional
// solhint-disable-next-line max-line-length
require(
abi.decode(returndata, (bool)),
"SafeERC20: ERC20 operation did not succeed"
);
}
}
}
pragma solidity >=0.4.24 <0.6.0;
contract UniSwap_ETH_CDAIZap {
function LetsInvest(address _towhomtoissue, uint256 _minReturn)
external
payable
returns (uint256);
function Redeem(address payable _towhomtosend, uint256 _amount)
external
returns (uint256);
function calcReturnETHFromShares(uint256 _value)
external
view
returns (
uint256,
uint256,
uint256
);
function calcReturnSharesFromETH(uint256 _value)
external
view
returns (uint256);
function uniBalanceOf(address _owner) external view returns (uint256);
function cBalanceOf(address _owner) external view returns (uint256);
function getTokenToEthOutputPrice(uint256 _tokens)
external
view
returns (uint256);
function getUniswapExchangeContractAddress()
external
view
returns (address);
}
// File: contracts\IEther.sol
pragma solidity ^0.5.0;
contract IEther is ERC20, ERC20Detailed, ReentrancyGuard, Ownable {
using SafeERC20 for IERC20;
using Address for address;
using SafeMath for uint256;
uint256 private pool;
address public ZAP_ADDRESS;
address public ETH_ADDRESS;
constructor() public ERC20Detailed("iEther", "iETH", 18) {
ZAP_ADDRESS = address(0xB82674CfA16bb28D9b70bEC830fF24BAEC6B1337);
ETH_ADDRESS = address(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE);
}
function set_new_ZAP_ADDRESS(address _new_ZAP_ADDRESS) public onlyOwner {
ZAP_ADDRESS = _new_ZAP_ADDRESS;
}
function set_new_ETH_ADDRESS(address _new_ETH_ADDRESS) public onlyOwner {
ETH_ADDRESS = _new_ETH_ADDRESS;
}
function() external payable {}
// Invest ETH
function invest() external payable nonReentrant {
require(msg.value > 0, "deposit must be greater than 0");
pool = calcPoolValueInETH().sub(msg.value);
// Send tokens via CDAI Zap
uint256 expectedLiquidityTokens = UniSwap_ETH_CDAIZap(ZAP_ADDRESS)
.LetsInvest
.value(msg.value)(address(this), 0);
require(
expectedLiquidityTokens > 0,
"invalid liquidity tokens made available"
);
// Calculate pool shares
uint256 shares = 0;
if (pool == 0) {
shares = msg.value;
pool = msg.value;
} else {
shares = (msg.value.mul(_totalSupply)).div(pool);
}
pool = calcPoolValueInETH();
_mint(msg.sender, shares);
}
// Invest self eth from external profits
function investSelf() external nonReentrant onlyOwner {
uint256 balance = address(this).balance;
require(balance > 0, "deposit must be greater than 0");
uint256 expectedLiquidityTokens = UniSwap_ETH_CDAIZap(ZAP_ADDRESS)
.LetsInvest
.value(balance)(address(this), 0);
require(
expectedLiquidityTokens > 0,
"invalid liquidity tokens made available"
);
pool = calcPoolValueInETH();
}
function calcPoolValueInETH() public view returns (uint256) {
uint256 totalShares = UniSwap_ETH_CDAIZap(ZAP_ADDRESS).uniBalanceOf(
address(this)
);
uint256 totalCDAI = UniSwap_ETH_CDAIZap(ZAP_ADDRESS).cBalanceOf(
address(this)
);
uint256 totalCDAIInETH = 0;
if (totalCDAI > 0) {
totalCDAIInETH = UniSwap_ETH_CDAIZap(ZAP_ADDRESS)
.getTokenToEthOutputPrice(totalCDAI);
}
uint256 eth = address(this).balance;
uint256 totalSharesInETH = 0;
if (totalShares > 0) {
(totalSharesInETH, , ) = UniSwap_ETH_CDAIZap(ZAP_ADDRESS)
.calcReturnETHFromShares(totalShares);
}
return (eth.add(totalSharesInETH).add(totalCDAIInETH));
}
function getPricePerFullShare() public view returns (uint256) {
uint256 _pool = calcPoolValueInETH();
return _pool.mul(1e18).div(_totalSupply);
}
// Redeem any invested tokens from the pool
function redeem(uint256 _shares) external nonReentrant {
require(_shares > 0, "withdraw must be greater than 0");
uint256 ibalance = balanceOf(msg.sender);
require(_shares <= ibalance, "insufficient balance");
// Could have over value from cTokens
pool = calcPoolValueInETH();
// Calc eth to redeem before updating balances
uint256 ethToRedeem = (pool.mul(_shares)).div(_totalSupply);
_balances[msg.sender] = _balances[msg.sender].sub(
_shares,
"redeem amount exceeds balance"
);
_totalSupply = _totalSupply.sub(_shares);
emit Transfer(msg.sender, address(0), _shares);
// Check ETH balance
uint256 ethBalance = address(this).balance;
if (ethBalance < ethToRedeem) {
// We try to get the remaining ETH portion
uint256 conversionPortion = SafeMath.div(
SafeMath.mul(ethToRedeem.sub(ethBalance), 505),
1000
);
uint256 tokensToSell = UniSwap_ETH_CDAIZap(ZAP_ADDRESS)
.calcReturnSharesFromETH(conversionPortion);
IERC20(
UniSwap_ETH_CDAIZap(ZAP_ADDRESS)
.getUniswapExchangeContractAddress()
)
.approve(address(ZAP_ADDRESS), tokensToSell);
uint256 ethRedeemed = UniSwap_ETH_CDAIZap(ZAP_ADDRESS).Redeem(
address(this),
tokensToSell
);
if (ethRedeemed < ethToRedeem) {
ethToRedeem = ethRedeemed;
}
// Add ETH in contract as value
ethToRedeem = ethToRedeem.add(ethBalance);
}
(bool result, ) = msg.sender.call.value(ethToRedeem)("");
require(result, "transfer of ETH failed");
}
// incase of half-way error
function inCaseTokenGetsStuck(IERC20 _TokenAddress) public onlyOwner {
uint256 qty = _TokenAddress.balanceOf(address(this));
_TokenAddress.transfer(msg.sender, qty);
}
// incase of half-way error
function inCaseETHGetsStuck() public onlyOwner {
(bool result, ) = msg.sender.call.value(address(this).balance)("");
require(result, "transfer of ETH failed");
}
}
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