Merge bdc767e into 7d42437

pooltogether · Oct 6, 2021 · c25b8b2 · c25b8b2
2 parents 7d42437 + bdc767e
commit c25b8b2
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Showing 2 changed files with 19 additions and 4 deletions.
diff --git a/contracts/libraries/ExtendedSafeCastLib.sol b/contracts/libraries/ExtendedSafeCastLib.sol
@@ -32,4 +32,19 @@ library ExtendedSafeCastLib {
         require(value <= type(uint208).max, "SafeCast: value doesn't fit in 208 bits");
         return uint208(value);
     }
+
+    /**
+     * @dev Returns the downcasted uint224 from uint256, reverting on
+     * overflow (when the input is greater than largest uint224).
+     *
+     * Counterpart to Solidity's `uint224` operator.
+     *
+     * Requirements:
+     *
+     * - input must fit into 224 bits
+     */
+    function toUint224(uint256 value) internal pure returns (uint224) {
+        require(value <= type(uint224).max, "SafeCast: value doesn't fit in 224 bits");
+        return uint224(value);
+    }
 }
diff --git a/contracts/libraries/TwabLib.sol b/contracts/libraries/TwabLib.sol
@@ -364,15 +364,15 @@ library TwabLib {
      */
     function _computeNextTwab(
         ObservationLib.Observation memory _currentTwab,
-        uint256 _currentBalance,
+        uint224 _currentBalance,
         uint32 _time
     ) private pure returns (ObservationLib.Observation memory) {
         // New twab amount = last twab amount (or zero) + (current amount * elapsed seconds)
         return
             ObservationLib.Observation({
-                amount: (uint256(_currentTwab.amount) +
-                    (_currentBalance * (_time.checkedSub(_currentTwab.timestamp, _time))))
-                    .toUint208(),
+                amount: _currentTwab.amount +
+                        _currentBalance *
+                        (_time.checkedSub(_currentTwab.timestamp, _time)),
                 timestamp: _time
             });
     }