creation_sourcecode: // Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>
  
  // This program is free software: you can redistribute it and/or modify
  // it under the terms of the GNU General Public License as published by
  // the Free Software Foundation, either version 3 of the License, or
  // (at your option) any later version.
  
  // This program is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  // GNU General Public License for more details.
  
  // You should have received a copy of the GNU General Public License
  // along with this program.  If not, see <http://www.gnu.org/licenses/>.
  
  // SPDX-License-Identifier: GPL-3.0-only
  pragma solidity ^0.8.3;
  
  /**
   * @title Proxy
   * @notice Basic proxy that delegates all calls to a fixed implementing contract.
   * The implementing contract cannot be upgraded.
   * @author Julien Niset - <julien@argent.xyz>
   */
  contract Proxy {
  
      address immutable public implementation;
  
      event Received(uint indexed value, address indexed sender, bytes data);
  
      constructor(address _implementation) {
          implementation = _implementation;
      }
  
      fallback() external payable {
          address target = implementation;
          // solhint-disable-next-line no-inline-assembly
          assembly {
              calldatacopy(0, 0, calldatasize())
              let result := delegatecall(gas(), target, 0, calldatasize(), 0, 0)
              returndatacopy(0, 0, returndatasize())
              switch result
              case 0 {revert(0, returndatasize())}
              default {return (0, returndatasize())}
          }
      }
  
      receive() external payable {
          emit Received(msg.value, msg.sender, "");
      }
  }