Contract Source Code:
File 1 of 1 : BTRFLY
// File: contracts/BTRFLY.sol
pragma solidity 0.7.5;
library EnumerableSet {
// To implement this library for multiple types with as little code
// repetition as possible, we write it in terms of a generic Set type with
// bytes32 values.
// The Set implementation uses private functions, and user-facing
// implementations (such as AddressSet) are just wrappers around the
// underlying Set.
// This means that we can only create new EnumerableSets for types that fit
// in bytes32.
struct Set {
// Storage of set values
bytes32[] _values;
// Position of the value in the `values` array, plus 1 because index 0
// means a value is not in the set.
mapping (bytes32 => uint256) _indexes;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function _add(Set storage set, bytes32 value) private returns (bool) {
if (!_contains(set, value)) {
set._values.push(value);
// The value is stored at length-1, but we add 1 to all indexes
// and use 0 as a sentinel value
set._indexes[value] = set._values.length;
return true;
} else {
return false;
}
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function _remove(Set storage set, bytes32 value) private returns (bool) {
// We read and store the value's index to prevent multiple reads from the same storage slot
uint256 valueIndex = set._indexes[value];
if (valueIndex != 0) { // Equivalent to contains(set, value)
// To delete an element from the _values array in O(1), we swap the element to delete with the last one in
// the array, and then remove the last element (sometimes called as 'swap and pop').
// This modifies the order of the array, as noted in {at}.
uint256 toDeleteIndex = valueIndex - 1;
uint256 lastIndex = set._values.length - 1;
// When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
// so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
bytes32 lastvalue = set._values[lastIndex];
// Move the last value to the index where the value to delete is
set._values[toDeleteIndex] = lastvalue;
// Update the index for the moved value
set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based
// Delete the slot where the moved value was stored
set._values.pop();
// Delete the index for the deleted slot
delete set._indexes[value];
return true;
} else {
return false;
}
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function _contains(Set storage set, bytes32 value) private view returns (bool) {
return set._indexes[value] != 0;
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function _length(Set storage set) private view returns (uint256) {
return set._values.length;
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function _at(Set storage set, uint256 index) private view returns (bytes32) {
require(set._values.length > index, "EnumerableSet: index out of bounds");
return set._values[index];
}
function _getValues( Set storage set_ ) private view returns ( bytes32[] storage ) {
return set_._values;
}
// TODO needs insert function that maintains order.
// TODO needs NatSpec documentation comment.
/**
* Inserts new value by moving existing value at provided index to end of array and setting provided value at provided index
*/
function _insert(Set storage set_, uint256 index_, bytes32 valueToInsert_ ) private returns ( bool ) {
require( set_._values.length > index_ );
require( !_contains( set_, valueToInsert_ ), "Remove value you wish to insert if you wish to reorder array." );
bytes32 existingValue_ = _at( set_, index_ );
set_._values[index_] = valueToInsert_;
return _add( set_, existingValue_);
}
struct Bytes4Set {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(Bytes4Set storage set, bytes4 value) internal returns (bool) {
return _add(set._inner, value);
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(Bytes4Set storage set, bytes4 value) internal returns (bool) {
return _remove(set._inner, value);
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(Bytes4Set storage set, bytes4 value) internal view returns (bool) {
return _contains(set._inner, value);
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function length(Bytes4Set storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(Bytes4Set storage set, uint256 index) internal view returns ( bytes4 ) {
return bytes4( _at( set._inner, index ) );
}
function getValues( Bytes4Set storage set_ ) internal view returns ( bytes4[] memory ) {
bytes4[] memory bytes4Array_;
for( uint256 iteration_ = 0; _length( set_._inner ) > iteration_; iteration_++ ) {
bytes4Array_[iteration_] = bytes4( _at( set_._inner, iteration_ ) );
}
return bytes4Array_;
}
function insert( Bytes4Set storage set_, uint256 index_, bytes4 valueToInsert_ ) internal returns ( bool ) {
return _insert( set_._inner, index_, valueToInsert_ );
}
struct Bytes32Set {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
return _add(set._inner, value);
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
return _remove(set._inner, value);
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
return _contains(set._inner, value);
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function length(Bytes32Set storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(Bytes32Set storage set, uint256 index) internal view returns ( bytes32 ) {
return _at(set._inner, index);
}
function getValues( Bytes32Set storage set_ ) internal view returns ( bytes4[] memory ) {
bytes4[] memory bytes4Array_;
for( uint256 iteration_ = 0; _length( set_._inner ) >= iteration_; iteration_++ ){
bytes4Array_[iteration_] = bytes4( at( set_, iteration_ ) );
}
return bytes4Array_;
}
function insert( Bytes32Set storage set_, uint256 index_, bytes32 valueToInsert_ ) internal returns ( bool ) {
return _insert( set_._inner, index_, valueToInsert_ );
}
// AddressSet
struct AddressSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(AddressSet storage set, address value) internal returns (bool) {
return _add(set._inner, bytes32(uint256(value)));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(AddressSet storage set, address value) internal returns (bool) {
return _remove(set._inner, bytes32(uint256(value)));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(AddressSet storage set, address value) internal view returns (bool) {
return _contains(set._inner, bytes32(uint256(value)));
}
/**
* @dev Returns the number of values in the set. O(1).
*/
function length(AddressSet storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(AddressSet storage set, uint256 index) internal view returns (address) {
return address(uint256(_at(set._inner, index)));
}
/**
* TODO Might require explicit conversion of bytes32[] to address[].
* Might require iteration.
*/
function getValues( AddressSet storage set_ ) internal view returns ( address[] memory ) {
address[] memory addressArray;
for( uint256 iteration_ = 0; _length(set_._inner) >= iteration_; iteration_++ ){
addressArray[iteration_] = at( set_, iteration_ );
}
return addressArray;
}
function insert(AddressSet storage set_, uint256 index_, address valueToInsert_ ) internal returns ( bool ) {
return _insert( set_._inner, index_, bytes32(uint256(valueToInsert_)) );
}
// UintSet
struct UintSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(UintSet storage set, uint256 value) internal returns (bool) {
return _add(set._inner, bytes32(value));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(UintSet storage set, uint256 value) internal returns (bool) {
return _remove(set._inner, bytes32(value));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(UintSet storage set, uint256 value) internal view returns (bool) {
return _contains(set._inner, bytes32(value));
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function length(UintSet storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(UintSet storage set, uint256 index) internal view returns (uint256) {
return uint256(_at(set._inner, index));
}
struct UInt256Set {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(UInt256Set storage set, uint256 value) internal returns (bool) {
return _add(set._inner, bytes32(value));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(UInt256Set storage set, uint256 value) internal returns (bool) {
return _remove(set._inner, bytes32(value));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(UInt256Set storage set, uint256 value) internal view returns (bool) {
return _contains(set._inner, bytes32(value));
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function length(UInt256Set storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(UInt256Set storage set, uint256 index) internal view returns (uint256) {
return uint256(_at(set._inner, index));
}
}
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);
}
library SafeMath {
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
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;
}
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
function sqrrt(uint256 a) internal pure returns (uint c) {
if (a > 3) {
c = a;
uint b = add( div( a, 2), 1 );
while (b < c) {
c = b;
b = div( add( div( a, b ), b), 2 );
}
} else if (a != 0) {
c = 1;
}
}
function percentageAmount( uint256 total_, uint8 percentage_ ) internal pure returns ( uint256 percentAmount_ ) {
return div( mul( total_, percentage_ ), 1000 );
}
function substractPercentage( uint256 total_, uint8 percentageToSub_ ) internal pure returns ( uint256 result_ ) {
return sub( total_, div( mul( total_, percentageToSub_ ), 1000 ) );
}
function percentageOfTotal( uint256 part_, uint256 total_ ) internal pure returns ( uint256 percent_ ) {
return div( mul(part_, 100) , total_ );
}
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow, so we distribute
return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
}
function quadraticPricing( uint256 payment_, uint256 multiplier_ ) internal pure returns (uint256) {
return sqrrt( mul( multiplier_, payment_ ) );
}
function bondingCurve( uint256 supply_, uint256 multiplier_ ) internal pure returns (uint256) {
return mul( multiplier_, supply_ );
}
}
abstract contract ERC20 is IERC20 {
using SafeMath for uint256;
// TODO comment actual hash value.
bytes32 constant private ERC20TOKEN_ERC1820_INTERFACE_ID = keccak256( "ERC20Token" );
// Present in ERC777
mapping (address => uint256) internal _balances;
// Present in ERC777
mapping (address => mapping (address => uint256)) internal _allowances;
// Present in ERC777
uint256 internal _totalSupply;
// Present in ERC777
string internal _name;
// Present in ERC777
string internal _symbol;
// Present in ERC777
uint8 internal _decimals;
constructor (string memory name_, string memory symbol_, uint8 decimals_) {
_name = name_;
_symbol = symbol_;
_decimals = decimals_;
}
function name() public view returns (string memory) {
return _name;
}
function symbol() public view returns (string memory) {
return _symbol;
}
function decimals() public view returns (uint8) {
return _decimals;
}
function totalSupply() public view override returns (uint256) {
return _totalSupply;
}
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(msg.sender, recipient, amount);
return true;
}
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(msg.sender, spender, amount);
return true;
}
function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(msg.sender, spender, _allowances[msg.sender][spender].add(addedValue));
return true;
}
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
_approve(msg.sender, spender, _allowances[msg.sender][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}
function _transfer(address sender, address recipient, uint256 amount) internal virtual {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
_balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
function _mint(address account_, uint256 amount_) internal virtual {
require(account_ != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address( this ), account_, amount_);
_totalSupply = _totalSupply.add(amount_);
_balances[account_] = _balances[account_].add(amount_);
emit Transfer(address( this ), account_, amount_);
}
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
_balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
function _approve(address owner, address spender, uint256 amount) internal virtual {
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);
}
function _beforeTokenTransfer( address from_, address to_, uint256 amount_ ) internal virtual { }
}
library Counters {
using SafeMath for uint256;
struct Counter {
uint256 _value; // default: 0
}
function current(Counter storage counter) internal view returns (uint256) {
return counter._value;
}
function increment(Counter storage counter) internal {
counter._value += 1;
}
function decrement(Counter storage counter) internal {
counter._value = counter._value.sub(1);
}
}
interface IERC2612Permit {
function permit(
address owner,
address spender,
uint256 amount,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
function nonces(address owner) external view returns (uint256);
}
abstract contract ERC20Permit is ERC20, IERC2612Permit {
using Counters for Counters.Counter;
mapping(address => Counters.Counter) private _nonces;
// keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
bytes32 public DOMAIN_SEPARATOR;
constructor() {
uint256 chainID;
assembly {
chainID := chainid()
}
DOMAIN_SEPARATOR = keccak256(
abi.encode(
keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
keccak256(bytes(name())),
keccak256(bytes("1")), // Version
chainID,
address(this)
)
);
}
function permit(
address owner,
address spender,
uint256 amount,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) public virtual override {
require(block.timestamp <= deadline, "Permit: expired deadline");
bytes32 hashStruct =
keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, amount, _nonces[owner].current(), deadline));
bytes32 _hash = keccak256(abi.encodePacked(uint16(0x1901), DOMAIN_SEPARATOR, hashStruct));
address signer = ecrecover(_hash, v, r, s);
require(signer != address(0) && signer == owner, "ZeroSwapPermit: Invalid signature");
_nonces[owner].increment();
_approve(owner, spender, amount);
}
function nonces(address owner) public view override returns (uint256) {
return _nonces[owner].current();
}
}
interface IOwnable {
function owner() external view returns (address);
function renounceOwnership() external;
function transferOwnership( address newOwner_ ) external;
}
contract Ownable is IOwnable {
address internal _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
constructor () {
_owner = msg.sender;
emit OwnershipTransferred( address(0), _owner );
}
function owner() public view override returns (address) {
return _owner;
}
modifier onlyOwner() {
require( _owner == msg.sender, "Ownable: caller is not the owner" );
_;
}
function renounceOwnership() public virtual override onlyOwner() {
emit OwnershipTransferred( _owner, address(0) );
_owner = address(0);
}
function transferOwnership( address newOwner_ ) public virtual override onlyOwner() {
require( newOwner_ != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred( _owner, newOwner_ );
_owner = newOwner_;
}
}
contract VaultOwned is Ownable {
address internal _vault;
function setVault( address vault_ ) public onlyOwner() returns ( bool ) {
_vault = vault_;
return true;
}
function vault() public view returns (address) {
return _vault;
}
modifier onlyVault() {
require( _vault == msg.sender, "VaultOwned: caller is not the Vault" );
_;
}
}
abstract contract FrozenToken is ERC20Permit, Ownable {
using SafeMath for uint256;
bool public isTokenFrozen = true;
mapping (address => bool ) public isAuthorisedOperators;
modifier onlyAuthorisedOperators () {
require(!isTokenFrozen || isAuthorisedOperators[msg.sender], 'Frozen: token frozen or msg.sender not authorised');
_;
}
function unFreezeToken () external onlyOwner () {
isTokenFrozen = false;
}
function changeAuthorisation (address operator, bool status) public onlyOwner {
require(operator != address(0), "Frozen: new operator cant be zero address");
isAuthorisedOperators[operator] = status;
}
function addBatchAuthorisedOperators(address[] memory authorisedOperatorsArray) external onlyOwner {
for (uint i = 0; i < authorisedOperatorsArray.length; i++) {
changeAuthorisation(authorisedOperatorsArray[i],true);
}
}
function transfer(address recipient, uint256 amount) public virtual override onlyAuthorisedOperators returns (bool){
_transfer(msg.sender, recipient, amount);
return true;
}
function transferFrom(address sender, address recipient, uint256 amount) public virtual override onlyAuthorisedOperators returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
}
contract BTRFLY is VaultOwned, FrozenToken {
using SafeMath for uint256;
constructor() ERC20("BTRFLY", "BTRFLY", 9) ERC20Permit() {
setVault(msg.sender);
}
function mint(address account_, uint256 amount_) external onlyVault() {
_mint(account_, amount_);
}
function burn(uint256 amount) public virtual {
_burn(msg.sender, amount);
}
function burnFrom(address account_, uint256 amount_) public virtual {
_burnFrom(account_, amount_);
}
function _burnFrom(address account_, uint256 amount_) public virtual {
uint256 decreasedAllowance_ =
allowance(account_, msg.sender).sub(
amount_,
"ERC20: burn amount exceeds allowance"
);
_approve(account_, msg.sender, decreasedAllowance_);
_burn(account_, amount_);
}
}