1 files changed, 73 insertions, 0 deletions
diff --git a/packages/contracts/src/current/utils/SafeMath/SafeMath.sol b/packages/contracts/src/current/utils/SafeMath/SafeMath.sol
new file mode 100644
index 000000000..955a9e379
--- /dev/null
+++ b/packages/contracts/src/current/utils/SafeMath/SafeMath.sol
@@ -0,0 +1,73 @@
+pragma solidity ^0.4.18;
+
+contract SafeMath {
+    function safeMul(uint a, uint b)
+        internal
+        pure
+        returns (uint256)
+    {
+        uint c = a * b;
+        assert(a == 0 || c / a == b);
+        return c;
+    }
+
+    function safeDiv(uint a, uint b)
+        internal
+        pure
+        returns (uint256)
+    {
+        uint c = a / b;
+        return c;
+    }
+
+    function safeSub(uint a, uint b)
+        internal
+        pure
+        returns (uint256)
+    {
+        assert(b <= a);
+        return a - b;
+    }
+
+    function safeAdd(uint a, uint b)
+        internal
+        pure
+        returns (uint256)
+    {
+        uint c = a + b;
+        assert(c >= a);
+        return c;
+    }
+
+    function max64(uint64 a, uint64 b)
+        internal
+        pure
+        returns (uint256)
+    {
+        return a >= b ? a : b;
+    }
+
+    function min64(uint64 a, uint64 b)
+        internal
+        pure
+        returns (uint256)
+    {
+        return a < b ? a : b;
+    }
+
+    function max256(uint256 a, uint256 b)
+        internal
+        pure
+        returns (uint256)
+    {
+        return a >= b ? a : b;
+    }
+
+    function min256(uint256 a, uint256 b)
+        internal
+        pure
+        returns (uint256)
+    {
+        return a < b ? a : b;
+    }
+}