Add uint to uint enumerable map (#3338)

contracts/utils/structs/EnumerableMap.sol

@@ -31,6 +31,7 @@ import "./EnumerableSet.sol";
  * - `uint256 -> address` (`UintToAddressMap`) since v3.0.0
  * - `address -> uint256` (`AddressToUintMap`) since v4.6.0
  * - `bytes32 -> bytes32` (`Bytes32ToBytes32`) since v4.6.0
+ * - `uint256 -> uint256` (`UintToUintMap`) since v4.7.0
  *
  * [WARNING]
  * ====
@@ -155,6 +156,98 @@ library EnumerableMap {
         return value;
     }
 
+    // UintToUintMap
+
+    struct UintToUintMap {
+        Bytes32ToBytes32Map _inner;
+    }
+
+    /**
+     * @dev Adds a key-value pair to a map, or updates the value for an existing
+     * key. O(1).
+     *
+     * Returns true if the key was added to the map, that is if it was not
+     * already present.
+     */
+    function set(
+        UintToUintMap storage map,
+        uint256 key,
+        uint256 value
+    ) internal returns (bool) {
+        return set(map._inner, bytes32(key), bytes32(value));
+    }
+
+    /**
+     * @dev Removes a value from a set. O(1).
+     *
+     * Returns true if the key was removed from the map, that is if it was present.
+     */
+    function remove(UintToUintMap storage map, uint256 key) internal returns (bool) {
+        return remove(map._inner, bytes32(key));
+    }
+
+    /**
+     * @dev Returns true if the key is in the map. O(1).
+     */
+    function contains(UintToUintMap storage map, uint256 key) internal view returns (bool) {
+        return contains(map._inner, bytes32(key));
+    }
+
+    /**
+     * @dev Returns the number of elements in the map. O(1).
+     */
+    function length(UintToUintMap storage map) internal view returns (uint256) {
+        return length(map._inner);
+    }
+
+    /**
+     * @dev Returns the element 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(UintToUintMap storage map, uint256 index) internal view returns (uint256, uint256) {
+        (bytes32 key, bytes32 value) = at(map._inner, index);
+        return (uint256(key), uint256(value));
+    }
+
+    /**
+     * @dev Tries to returns the value associated with `key`.  O(1).
+     * Does not revert if `key` is not in the map.
+     */
+    function tryGet(UintToUintMap storage map, uint256 key) internal view returns (bool, uint256) {
+        (bool success, bytes32 value) = tryGet(map._inner, bytes32(key));
+        return (success, uint256(value));
+    }
+
+    /**
+     * @dev Returns the value associated with `key`.  O(1).
+     *
+     * Requirements:
+     *
+     * - `key` must be in the map.
+     */
+    function get(UintToUintMap storage map, uint256 key) internal view returns (uint256) {
+        return uint256(get(map._inner, bytes32(key)));
+    }
+
+    /**
+     * @dev Same as {get}, with a custom error message when `key` is not in the map.
+     *
+     * CAUTION: This function is deprecated because it requires allocating memory for the error
+     * message unnecessarily. For custom revert reasons use {tryGet}.
+     */
+    function get(
+        UintToUintMap storage map,
+        uint256 key,
+        string memory errorMessage
+    ) internal view returns (uint256) {
+        return uint256(get(map._inner, bytes32(key), errorMessage));
+    }
+
     // UintToAddressMap
 
     struct UintToAddressMap {
@@ -310,8 +403,6 @@ library EnumerableMap {
     /**
      * @dev Tries to returns the value associated with `key`.  O(1).
      * Does not revert if `key` is not in the map.
-     *
-     * _Available since v3.4._
      */
     function tryGet(AddressToUintMap storage map, address key) internal view returns (bool, uint256) {
         (bool success, bytes32 value) = tryGet(map._inner, bytes32(uint256(uint160(key))));