dexorder

lib_openzeppelin_contracts/contracts/token/ERC20/extensions/ERC20Capped.sol

@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/ERC20Capped.sol)
+
+pragma solidity ^0.8.20;
+
+import {ERC20} from "../ERC20.sol";
+
+/**
+ * @dev Extension of {ERC20} that adds a cap to the supply of tokens.
+ */
+abstract contract ERC20Capped is ERC20 {
+    uint256 private immutable _cap;
+
+    /**
+     * @dev Total supply cap has been exceeded.
+     */
+    error ERC20ExceededCap(uint256 increasedSupply, uint256 cap);
+
+    /**
+     * @dev The supplied cap is not a valid cap.
+     */
+    error ERC20InvalidCap(uint256 cap);
+
+    /**
+     * @dev Sets the value of the `cap`. This value is immutable, it can only be
+     * set once during construction.
+     */
+    constructor(uint256 cap_) {
+        if (cap_ == 0) {
+            revert ERC20InvalidCap(0);
+        }
+        _cap = cap_;
+    }
+
+    /**
+     * @dev Returns the cap on the token's total supply.
+     */
+    function cap() public view virtual returns (uint256) {
+        return _cap;
+    }
+
+    /**
+     * @dev See {ERC20-_update}.
+     */
+    function _update(address from, address to, uint256 value) internal virtual override {
+        super._update(from, to, value);
+
+        if (from == address(0)) {
+            uint256 maxSupply = cap();
+            uint256 supply = totalSupply();
+            if (supply > maxSupply) {
+                revert ERC20ExceededCap(supply, maxSupply);
+            }
+        }
+    }
+}