Rename bytes.rawAddress and add bytes.contentAddress

packages/contracts/src/contracts/current/test/TestLibBytes/TestLibBytes.sol

@@ -243,7 +243,7 @@ contract TestLibBytes {
         require(dest + length <= mem.length);
 
         // Get pointer to memory contents
-        uint256 offset = mem.getMemAddress() + 32;
+        uint256 offset = mem.contentAddress();
 
         // Execute memCopy adjusted for memory array location
         LibBytes.memCopy(offset + dest, offset + source, length);

packages/contracts/src/contracts/current/utils/LibBytes/LibBytes.sol

@@ -19,6 +19,7 @@
 pragma solidity ^0.4.24;
 
 library LibBytes {
+    using LibBytes for bytes;
 
     // Revert reasons
     string constant GREATER_THAN_ZERO_LENGTH_REQUIRED = "GREATER_THAN_ZERO_LENGTH_REQUIRED";
@@ -30,8 +31,10 @@ library LibBytes {
 
     /// @dev Gets the memory address for a byte array.
     /// @param input Byte array to lookup.
-    /// @return memoryAddress Memory address of byte array.
-    function getMemAddress(bytes memory input)
+    /// @return memoryAddress Memory address of byte array. This
+    ///         points to the header of the byte array which contains
+    ///         the length.
+    function rawAddress(bytes memory input)
         internal
         pure
         returns (uint256 memoryAddress)
@@ -42,6 +45,20 @@ library LibBytes {
         return memoryAddress;
     }
     
+    /// @dev Gets the memory address for the contents of a byte array.
+    /// @param input Byte array to lookup.
+    /// @return memoryAddress Memory address of the contents of the byte array.
+    function contentAddress(bytes memory input)
+        internal
+        pure
+        returns (uint256 memoryAddress)
+    {
+        assembly {
+            memoryAddress := add(input, 32)
+        }
+        return memoryAddress;
+    }
+
     /// @dev Copies `length` bytes from memory location `source` to `dest`.
     /// @param dest memory address to copy bytes to.
     /// @param source memory address to copy bytes from.
@@ -393,8 +410,8 @@ library LibBytes {
         // Allocate memory and copy value to result
         result = new bytes(nestedBytesLength);
         memCopy(
-            getMemAddress(result) + 32, // +32 skips array length
-            getMemAddress(b) + index + 32,
+            result.contentAddress(),
+            b.contentAddress() + index,
             nestedBytesLength
         );
 
@@ -422,9 +439,9 @@ library LibBytes {
 
         // Copy <input> into <b>
         memCopy(
-            getMemAddress(b) + 32 + index,  // +32 to skip length of <b>
-            getMemAddress(input),           // includes length of <input>
-            input.length + 32               // +32 bytes to store <input> length
+            b.contentAddress() + index,
+            input.rawAddress(), // includes length of <input>
+            input.length + 32   // +32 bytes to store <input> length
         );
     }