// Contract: Dariablock
// Target function: function approveAndCall(address spender, uint256 value) public override returns (bool)
     * @notice Transfer tokens from `msg.sender` to another address and then call `onTransferReceived` on receiver
     * @param to address The address which you want to transfer to
     * @param value uint256 The amount of tokens to be transferred
     * @return true unless throwing
     */
    function transferAndCall(address to, uint256 value) external returns (bool);

    /**
     * @notice Transfer tokens from `msg.sender` to another address and then call `onTransferReceived` on receiver
     * @param to address The address which you want to transfer to
     * @param value uint256 The amount of tokens to be transferred
     * @param data bytes Additional data with no specified format, sent in call to `to`
     * @return true unless throwing
     */
    function transferAndCall(address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @notice Transfer tokens from one address to another and then call `onTransferReceived` on receiver
     * @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
     * @return true unless throwing
     */
    function transferFromAndCall(address from, address to, uint256 value) external returns (bool);

    /**
     * @notice Transfer tokens from one address to another and then call `onTransferReceived` on receiver
     * @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
     * @param data bytes Additional data with no specified format, sent in call to `to`
     * @return true unless throwing
     */
    function transferFromAndCall(address from, address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @notice Approve the passed address to spend the specified amount of tokens on behalf of msg.sender
     * and then call `onApprovalReceived` on spender.
     * 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:
     *
     * @param spender address The address which will spend the funds
     * @param value uint256 The amount of tokens to be spent
     */
    function approveAndCall(address spender, uint256 value) external returns (bool);

    /**
     * @notice Approve the passed address to spend the specified amount of tokens on behalf of msg.sender
     * and then call `onApprovalReceived` on spender.
     * 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:
     *
     * @param spender address The address which will spend the funds
     * @param value uint256 The amount of tokens to be spent
     * @param data bytes Additional data with no specified format, sent in call to `spender`
     */
    function approveAndCall(address spender, uint256 value, bytes calldata data) external returns (bool);
}

//

pragma solidity ^0.6.7;

/**
 * @title IERC1363Receiver Interface
 * @author Vittorio Minacori 
 * @dev Interface for any contract that wants to support transferAndCall or transferFromAndCall
 *  from ERC1363 token contracts as defined in
 *
 */
interface IERC1363Receiver {
    /*
     * Note: the ERC-165 identifier for this interface is 0x88a7ca5c.
     * 0x88a7ca5c === bytes4(keccak256("onTransferReceived(address,address,uint256,bytes)"))
     */

    /**
     * @notice Handle the receipt of ERC1363 tokens
     * @dev Any ERC1363 smart contract calls this function on the recipient
     * after a `transfer` or a `transferFrom`. This function MAY throw to revert and reject the
     * transfer. Return of other than the magic value MUST result in the
     * transaction being reverted.
     * Note: the token contract address is always the message sender.
     * @param operator address The address which called `transferAndCall` or `transferFromAndCall` function
     * @param from address The address which are token transferred from
     * @param value uint256 The amount of tokens transferred
     * @param data bytes Additional data with no specified format
     * @return `bytes4(keccak256("onTransferReceived(address,address,uint256,bytes)"))`
     *  unless throwing
     */
    function onTransferReceived(address operator, address from, uint256 value, bytes calldata data) external returns (bytes4); // solhint-disable-line  max-line-length
}



pragma solidity ^0.6.7;

/**
 * @title IERC1363Spender Interface
 * @author Vittorio Minacori
 * @dev Interface for any contract that wants to support approveAndCall
 *  from ERC1363 token contracts as defined in
 *
 */
interface IERC1363Spender {
    /*
     * Note: the ERC-165 identifier for this interface is 0x7b04a2d0.
     * 0x7b04a2d0 === bytes4(keccak256("onApprovalReceived(address,uint256,bytes)"))
     */

    /**
     * @notice Handle the approval of ERC1363 tokens
     * @dev Any ERC1363 smart contract calls this function on the recipient
     * after an `approve`. This function MAY throw to revert and reject the
     * approval. Return of other than the magic value MUST result in the
     * transaction being reverted.
     * Note: the token contract address is always the message sender.
     * @param owner address The address which called `approveAndCall` function
     * @param value uint256 The amount of tokens to be spent
     * @param data bytes Additional data with no specified format
     * @return `bytes4(keccak256("onApprovalReceived(address,uint256,bytes)"))`
     *  unless throwing
     */
    function onApprovalReceived(address owner, uint256 value, bytes calldata data) external returns (bytes4);
}



pragma solidity ^0.6.7;

/**
 * @dev Library used to query support of an interface declared via {IERC165}.
 *
 * Note that these functions return the actual result of the query: they do not
 * `revert` if an interface is not supported. It is up to the caller to decide
 * what to do in these cases.
 */
library ERC165Checker {
    // As per the EIP-165 spec, no interface should ever match 0xffffffff
    bytes4 private constant _INTERFACE_ID_INVALID = 0xffffffff;

    /*
     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7
     */
    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;

    /**
     * @dev Returns true if `account` supports the {IERC165} interface,
     */
    function supportsERC165(address account) internal view returns (bool) {
        // Any contract that implements ERC165 must explicitly indicate support of
        // InterfaceId_ERC165 and explicitly indicate non-support of InterfaceId_Invalid
        return _supportsERC165Interface(account, _INTERFACE_ID_ERC165) &&
            !_supportsERC165Interface(account, _INTERFACE_ID_INVALID);
    }

    /**
     * @dev Returns true if `account` supports the interface defined by
     * `interfaceId`. Support for {IERC165} itself is queried automatically.
     *
     * See {IERC165-supportsInterface}.
     */
    function supportsInterface(address account, bytes4 interfaceId) internal view returns (bool) {
        // query support of both ERC165 as per the spec and support of _interfaceId
        return supportsERC165(account) &&
            _supportsERC165Interface(account, interfaceId);
    }

    /**
     * @dev Returns true if `account` supports all the interfaces defined in
     * `interfaceIds`. Support for {IERC165} itself is queried automatically.
     *
     * Batch-querying can lead to gas savings by skipping repeated checks for
     * {IERC165} support.
     *
     * See {IERC165-supportsInterface}.
     */
    function supportsAllInterfaces(address account, bytes4[] memory interfaceIds) internal view returns (bool) {
        // query support of ERC165 itself
        if (!supportsERC165(account)) {
            return false;
        }

        // query support of each interface in _interfaceIds
        for (uint256 i = 0; i < interfaceIds.length; i++) {
            if (!_supportsERC165Interface(account, interfaceIds[i])) {
                return false;
            }
        }

        // all interfaces supported
        return true;
    }

    /**
     * @notice Query if a contract implements an interface, does not check ERC165 support
     * @param account The address of the contract to query for support of an interface
     * @param interfaceId The interface identifier, as specified in ERC-165
     * @return true if the contract at account indicates support of the interface with
     * identifier interfaceId, false otherwise
     * @dev Assumes that account contains a contract that supports ERC165, otherwise
     * the behavior of this method is undefined. This precondition can be checked
     * with {supportsERC165}.
     * Interface identification is specified in ERC-165.
     */
    function _supportsERC165Interface(address account, bytes4 interfaceId) private view returns (bool) {
        // success determines whether the staticcall succeeded and result determines
        // whether the contract at account indicates support of _interfaceId
        (bool success, bool result) = _callERC165SupportsInterface(account, interfaceId);

        return (success && result);
    }

    /**
     * @notice Calls the function with selector 0x01ffc9a7 (ERC165) and suppresses throw
     * @param account The address of the contract to query for support of an interface
     * @param interfaceId The interface identifier, as specified in ERC-165
     * @return success true if the STATICCALL succeeded, false otherwise
     * @return result true if the STATICCALL succeeded and the contract at account
     * indicates support of the interface with identifier interfaceId, false otherwise
     */
    function _callERC165SupportsInterface(address account, bytes4 interfaceId)
        private
        view
        returns (bool, bool)
    {
        bytes memory encodedParams = abi.encodeWithSelector(_INTERFACE_ID_ERC165, interfaceId);
        (bool success, bytes memory result) = account.staticcall{ gas: 30000 }(encodedParams);
        if (result.length < 32) return (false, false);
        return (success, abi.decode(result, (bool)));
    }
}



pragma solidity ^0.6.7;


/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts may inherit from this and call {_registerInterface} to declare
 * their support of an interface.
 */
contract ERC165 is IERC165 {
    /*
     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7
     */
    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;

    /**
     * @dev Mapping of interface ids to whether or not it's supported.
     */
    mapping(bytes4 => bool) private _supportedInterfaces;

    constructor () internal {
        // Derived contracts need only register support for their own interfaces,
        // we register support for ERC165 itself here
        _registerInterface(_INTERFACE_ID_ERC165);
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     *
     * Time complexity O(1), guaranteed to always use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) public view override returns (bool) {
        return _supportedInterfaces[interfaceId];
    }

    /**
     * @dev Registers the contract as an implementer of the interface defined by
     * `interfaceId`. Support of the actual ERC165 interface is automatic and
     * registering its interface id is not required.
     *
     * See {IERC165-supportsInterface}.
     *
     * Requirements:
     *
     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).
     */
    function _registerInterface(bytes4 interfaceId) internal virtual {
        require(interfaceId != 0xffffffff, "ERC165: invalid interface id");
        _supportedInterfaces[interfaceId] = true;
    }
}



pragma solidity ^0.6.7;








/**
 * @title ERC1363
 * @author Vittorio Minacori
 * @dev Implementation of an ERC1363 interface
 */
contract ERC1363 is ERC20, IERC1363, ERC165 {
    using Address for address;

    /*
     * Note: the ERC-165 identifier for this interface is 0x4bbee2df.
     * 0x4bbee2df ===
     *   bytes4(keccak256('transferAndCall(address,uint256)')) ^
     *   bytes4(keccak256('transferAndCall(address,uint256,bytes)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256,bytes)'))
     */
    bytes4 internal constant _INTERFACE_ID_ERC1363_TRANSFER = 0x4bbee2df;

    /*
     * Note: the ERC-165 identifier for this interface is 0xfb9ec8ce.
     * 0xfb9ec8ce ===
     *   bytes4(keccak256('approveAndCall(address,uint256)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256,bytes)'))
     */
    bytes4 internal constant _INTERFACE_ID_ERC1363_APPROVE = 0xfb9ec8ce;

    // Equals to `bytes4(keccak256("onTransferReceived(address,address,uint256,bytes)"))`
    // which can be also obtained as `IERC1363Receiver(0).onTransferReceived.selector`
    bytes4 private constant _ERC1363_RECEIVED = 0x88a7ca5c;

    // Equals to `bytes4(keccak256("onApprovalReceived(address,uint256,bytes)"))`
    // which can be also obtained as `IERC1363Spender(0).onApprovalReceived.selector`
    bytes4 private constant _ERC1363_APPROVED = 0x7b04a2d0;

    /**
     * @param name Name of the token
     * @param symbol A symbol to be used as ticker
     */
    constructor (
        string memory name,
        string memory symbol
    ) public payable ERC20(name, symbol) {
        // register the supported interfaces to conform to ERC1363 via ERC165
        _registerInterface(_INTERFACE_ID_ERC1363_TRANSFER);
        _registerInterface(_INTERFACE_ID_ERC1363_APPROVE);
    }

    /**
     * @dev Transfer tokens to a specified address and then execute a callback on recipient.
     * @param to The address to transfer to.
     * @param value The amount to be transferred.
     * @return A boolean that indicates if the operation was successful.
     */
    function transferAndCall(address to, uint256 value) public override returns (bool) {
        return transferAndCall(to, value, "");
    }

    /**
     * @dev Transfer tokens to a specified address and then execute a callback on recipient.
     * @param to The address to transfer to
     * @param value The amount to be transferred
     * @param data Additional data with no specified format
     * @return A boolean that indicates if the operation was successful.
     */
    function transferAndCall(address to, uint256 value, bytes memory data) public override returns (bool) {
        transfer(to, value);
        require(_checkAndCallTransfer(_msgSender(), to, value, data), "ERC1363: _checkAndCallTransfer reverts");
        return true;
    }

    /**
     * @dev Transfer tokens from one address to another and then execute a callback on recipient.
     * @param from The address which you want to send tokens from
     * @param to The address which you want to transfer to
     * @param value The amount of tokens to be transferred
     * @return A boolean that indicates if the operation was successful.
     */
    function transferFromAndCall(address from, address to, uint256 value) public override returns (bool) {
        return transferFromAndCall(from, to, value, "");
    }

    /**
     * @dev Transfer tokens from one address to another and then execute a callback on recipient.
     * @param from The address which you want to send tokens from
     * @param to The address which you want to transfer to
     * @param value The amount of tokens to be transferred
     * @param data Additional data with no specified format
     * @return A boolean that indicates if the operation was successful.
     */
    function transferFromAndCall(address from, address to, uint256 value, bytes memory data) public override returns (bool) {
        transferFrom(from, to, value);
        require(_checkAndCallTransfer(from, to, value, data), "ERC1363: _checkAndCallTransfer reverts");
        return true;
    }