pragmasolidity ^0.5.8;import"./IERC20.sol";
import"./SafeMath.sol";
/**
* @title Standard ERC20 token
*
* @dev Implementation of the basic standard token.
* https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md
* Originally based on code by FirstBlood:
* https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
*
* This implementation emits additional Approval events, allowing applications to reconstruct the allowance status for
* all accounts just by listening to said events. Note that this isn't required by the specification, and other
* compliant implementations may not do it.
*/contractERC20isIERC20{
usingSafeMathforuint256;
mapping(address=>uint256) private _balances;
mapping(address=>mapping(address=>uint256)) private _allowed;
uint256private _totalSupply;
/**
* @dev Total number of tokens in existence
*/functiontotalSupply() publicviewreturns (uint256) {
return _totalSupply;
}
/**
* @dev Gets the balance of the specified address.
* @param owner The address to query the balance of.
* @return An uint256 representing the amount owned by the passed address.
*/functionbalanceOf(address owner) publicviewreturns (uint256) {
return _balances[owner];
}
/**
* @dev Function to check the amount of tokens that an owner allowed to a spender.
* @param owner address The address which owns the funds.
* @param spender address The address which will spend the funds.
* @return A uint256 specifying the amount of tokens still available for the spender.
*/functionallowance(address owner, address spender) publicviewreturns (uint256) {
return _allowed[owner][spender];
}
/**
* @dev Transfer token for a specified address
* @param to The address to transfer to.
* @param value The amount to be transferred.
*/functiontransfer(address to, uint256 value) publicreturns (bool) {
_transfer(msg.sender, to, value);
returntrue;
}
/**
* @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
* 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
* @param spender The address which will spend the funds.
* @param value The amount of tokens to be spent.
*/functionapprove(address spender, uint256 value) publicreturns (bool) {
_approve(msg.sender, spender, value);
returntrue;
}
/**
* @dev Transfer tokens from one address to another.
* Note that while this function emits an Approval event, this is not required as per the specification,
* and other compliant implementations may not emit the event.
* @param from address The address which you want to send tokens from
* @param to address The address which you want to transfer to
* @param value uint256 the amount of tokens to be transferred
*/functiontransferFrom(addressfrom, address to, uint256 value) publicreturns (bool) {
_transfer(from, to, value);
_approve(from, msg.sender, _allowed[from][msg.sender].sub(value));
returntrue;
}
/**
* @dev Increase the amount of tokens that an owner allowed to a spender.
* approve should be called when allowed_[_spender] == 0. To increment
* allowed value is better to use this function to avoid 2 calls (and wait until
* the first transaction is mined)
* From MonolithDAO Token.sol
* Emits an Approval event.
* @param spender The address which will spend the funds.
* @param addedValue The amount of tokens to increase the allowance by.
*/functionincreaseAllowance(address spender, uint256 addedValue) publicreturns (bool) {
_approve(msg.sender, spender, _allowed[msg.sender][spender].add(addedValue));
returntrue;
}
/**
* @dev Decrease the amount of tokens that an owner allowed to a spender.
* approve should be called when allowed_[_spender] == 0. To decrement
* allowed value is better to use this function to avoid 2 calls (and wait until
* the first transaction is mined)
* From MonolithDAO Token.sol
* Emits an Approval event.
* @param spender The address which will spend the funds.
* @param subtractedValue The amount of tokens to decrease the allowance by.
*/functiondecreaseAllowance(address spender, uint256 subtractedValue) publicreturns (bool) {
_approve(msg.sender, spender, _allowed[msg.sender][spender].sub(subtractedValue));
returntrue;
}
/**
* @dev Transfer token for a specified addresses
* @param from The address to transfer from.
* @param to The address to transfer to.
* @param value The amount to be transferred.
*/function_transfer(addressfrom, address to, uint256 value) internal{
require(to !=address(0));
_balances[from] = _balances[from].sub(value);
_balances[to] = _balances[to].add(value);
emit Transfer(from, to, value);
}
/**
* @dev Internal function that mints an amount of the token and assigns it to
* an account. This encapsulates the modification of balances such that the
* proper events are emitted.
* @param account The account that will receive the created tokens.
* @param value The amount that will be created.
*/function_mint(address account, uint256 value) internal{
require(account !=address(0));
_totalSupply = _totalSupply.add(value);
_balances[account] = _balances[account].add(value);
emit Transfer(address(0), account, value);
}
/**
* @dev Internal function that burns an amount of the token of a given
* account.
* @param account The account whose tokens will be burnt.
* @param value The amount that will be burnt.
*/function_burn(address account, uint256 value) internal{
require(account !=address(0));
_totalSupply = _totalSupply.sub(value);
_balances[account] = _balances[account].sub(value);
emit Transfer(account, address(0), value);
}
/**
* @dev Approve an address to spend another addresses' tokens.
* @param owner The address that owns the tokens.
* @param spender The address that will spend the tokens.
* @param value The number of tokens that can be spent.
*/function_approve(address owner, address spender, uint256 value) internal{
require(spender !=address(0));
require(owner !=address(0));
_allowed[owner][spender] = value;
emit Approval(owner, spender, value);
}
/**
* @dev Internal function that burns an amount of the token of a given
* account, deducting from the sender's allowance for said account. Uses the
* internal burn function.
* Emits an Approval event (reflecting the reduced allowance).
* @param account The account whose tokens will be burnt.
* @param value The amount that will be burnt.
*/function_burnFrom(address account, uint256 value) internal{
_burn(account, value);
_approve(account, msg.sender, _allowed[account][msg.sender].sub(value));
}
}
Contract Source Code
File 2 of 7: ERC20Burnable.sol
pragmasolidity ^0.5.8;import"./ERC20.sol";
/**
* @title Burnable Token
* @dev Token that can be irreversibly burned (destroyed).
*/contractERC20BurnableisERC20{
/**
* @dev Burns a specific amount of tokens.
* @param value The amount of token to be burned.
*/functionburn(uint256 value) public{
_burn(msg.sender, value);
}
/**
* @dev Burns a specific amount of tokens from the target address and decrements allowance
* @param from address The address which you want to send tokens from
* @param value uint256 The amount of token to be burned
*/functionburnFrom(addressfrom, uint256 value) public{
_burnFrom(from, value);
}
}
Contract Source Code
File 3 of 7: ERC20Detailed.sol
pragmasolidity ^0.5.8;import"./IERC20.sol";
/**
* @title ERC20Detailed token
* @dev The decimals are only for visualization purposes.
* All the operations are done using the smallest and indivisible token unit,
* just as on Ethereum all the operations are done in wei.
*/contractERC20DetailedisIERC20{
stringprivate _name;
stringprivate _symbol;
uint8private _decimals;
constructor (stringmemory name, stringmemory symbol, uint8 decimals) public{
_name = name;
_symbol = symbol;
_decimals = decimals;
}
/**
* @return the name of the token.
*/functionname() publicviewreturns (stringmemory) {
return _name;
}
/**
* @return the symbol of the token.
*/functionsymbol() publicviewreturns (stringmemory) {
return _symbol;
}
/**
* @return the number of decimals of the token.
*/functiondecimals() publicviewreturns (uint8) {
return _decimals;
}
}
pragmasolidity ^0.5.8;/**
* @title Ownable
* @dev The Ownable contract has an owner address, and provides basic authorization control
* functions, this simplifies the implementation of "user permissions".
*/contractOwnable{
addressprivate _owner;
eventOwnershipTransferred(addressindexed previousOwner, addressindexed newOwner);
/**
* @dev The Ownable constructor sets the original `owner` of the contract to the sender
* account.
*/constructor () internal{
_owner =msg.sender;
emit OwnershipTransferred(address(0), _owner);
}
/**
* @return the address of the owner.
*/functionowner() publicviewreturns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/modifieronlyOwner() {
require(isOwner());
_;
}
/**
* @return true if `msg.sender` is the owner of the contract.
*/functionisOwner() publicviewreturns (bool) {
returnmsg.sender== _owner;
}
/**
* @dev Allows the current owner to relinquish control of the contract.
* @notice Renouncing to ownership will leave the contract without an owner.
* It will not be possible to call the functions with the `onlyOwner`
* modifier anymore.
*/functionrenounceOwnership() publiconlyOwner{
emit OwnershipTransferred(_owner, address(0));
_owner =address(0);
}
/**
* @dev Allows the current owner to transfer control of the contract to a newOwner.
* @param newOwner The address to transfer ownership to.
*/functiontransferOwnership(address newOwner) publiconlyOwner{
_transferOwnership(newOwner);
}
/**
* @dev Transfers control of the contract to a newOwner.
* @param newOwner The address to transfer ownership to.
*/function_transferOwnership(address newOwner) internal{
require(newOwner !=address(0));
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
Contract Source Code
File 6 of 7: SafeMath.sol
pragmasolidity ^0.5.8;/**
* @title SafeMath
* @dev Unsigned math operations with safety checks that revert on error
*/librarySafeMath{
/**
* @dev Multiplies two unsigned integers, reverts on overflow.
*/functionmul(uint256 a, uint256 b) internalpurereturns (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-solidity/pull/522if (a ==0) {
return0;
}
uint256 c = a * b;
require(c / a == b);
return c;
}
/**
* @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
*/functiondiv(uint256 a, uint256 b) internalpurereturns (uint256) {
// Solidity only automatically asserts when dividing by 0require(b >0);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't holdreturn c;
}
/**
* @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
*/functionsub(uint256 a, uint256 b) internalpurereturns (uint256) {
require(b <= a);
uint256 c = a - b;
return c;
}
/**
* @dev Adds two unsigned integers, reverts on overflow.
*/functionadd(uint256 a, uint256 b) internalpurereturns (uint256) {
uint256 c = a + b;
require(c >= a);
return c;
}
/**
* @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
* reverts when dividing by zero.
*/functionmod(uint256 a, uint256 b) internalpurereturns (uint256) {
require(b !=0);
return a % b;
}
}