added tokenVault contract

Author: quirps

src/TokenVault.sol

@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+contract TokenVault {
+    mapping(address => uint256) public balances;
+    uint256 public totalValue;
+
+    // A simple, unoptimized deposit function
+    function deposit(uint256 amount) public payable {
+        require(msg.value == amount, "Must send exact ETH amount");
+        balances[msg.sender] += amount;
+        totalValue += amount;
+        // ... imagine logic for interacting with a separate ERC20 token here
+    }
+
+    // A slightly complex function for optimization comparison
+    function _transferEth(address recipient, uint256 amount) internal {
+        // Option 1: Low-level call (more gas efficient for simple transfers)
+        (bool success, ) = recipient.call{value: amount}("");
+        require(success, "ETH transfer failed");
+    }
+
+    function withdrawOptimized(uint256 amount) public {
+        require(balances[msg.sender] >= amount, "Insufficient balance");
+        balances[msg.sender] -= amount;
+        totalValue -= amount;
+        _transferEth(msg.sender, amount); // Uses the optimized internal transfer
+    }
+}