diff --git a/include/utils/SharedBuffer.h b/include/utils/SharedBuffer.h
index 1d6d497fc..b6709537e 100644
--- a/include/utils/SharedBuffer.h
+++ b/include/utils/SharedBuffer.h
@@ -44,9 +44,6 @@ public:
      * users.
      */
     static          ssize_t                 dealloc(const SharedBuffer* released);
-    
-    //! get the SharedBuffer from the data pointer
-    static  inline  const SharedBuffer*     sharedBuffer(const void* data);
 
     //! access the data for read
     inline          const void*             data() const;
@@ -94,7 +91,8 @@ public:
 private:
         inline SharedBuffer() { }
         inline ~SharedBuffer() { }
-        inline SharedBuffer(const SharedBuffer&);
+        SharedBuffer(const SharedBuffer&);
+        SharedBuffer& operator = (const SharedBuffer&);
  
         // 16 bytes. must be sized to preserve correct alignment.
         mutable int32_t        mRefs;
@@ -104,10 +102,6 @@ private:
 
 // ---------------------------------------------------------------------------
 
-const SharedBuffer* SharedBuffer::sharedBuffer(const void* data) {
-    return data ? reinterpret_cast<const SharedBuffer *>(data)-1 : 0;
-}
-
 const void* SharedBuffer::data() const {
     return this + 1;
 }
@@ -120,19 +114,16 @@ size_t SharedBuffer::size() const {
     return mSize;
 }
 
-SharedBuffer* SharedBuffer::bufferFromData(void* data)
-{
-    return ((SharedBuffer*)data)-1;
+SharedBuffer* SharedBuffer::bufferFromData(void* data) {
+    return data ? static_cast<SharedBuffer *>(data)-1 : 0;
 }
     
-const SharedBuffer* SharedBuffer::bufferFromData(const void* data)
-{
-    return ((const SharedBuffer*)data)-1;
+const SharedBuffer* SharedBuffer::bufferFromData(const void* data) {
+    return data ? static_cast<const SharedBuffer *>(data)-1 : 0;
 }
 
-size_t SharedBuffer::sizeFromData(const void* data)
-{
-    return (((const SharedBuffer*)data)-1)->mSize;
+size_t SharedBuffer::sizeFromData(const void* data) {
+    return data ? bufferFromData(data)->mSize : 0;
 }
 
 bool SharedBuffer::onlyOwner() const {
diff --git a/libs/utils/VectorImpl.cpp b/libs/utils/VectorImpl.cpp
index 020ec15c9..8083bba0e 100644
--- a/libs/utils/VectorImpl.cpp
+++ b/libs/utils/VectorImpl.cpp
@@ -51,7 +51,7 @@ VectorImpl::VectorImpl(const VectorImpl& rhs)
         mFlags(rhs.mFlags), mItemSize(rhs.mItemSize)
 {
     if (mStorage) {
-        SharedBuffer::sharedBuffer(mStorage)->acquire();
+        SharedBuffer::bufferFromData(mStorage)->acquire();
     }
 }
 
@@ -73,7 +73,7 @@ VectorImpl& VectorImpl::operator = (const VectorImpl& rhs)
         if (rhs.mCount) {
             mStorage = rhs.mStorage;
             mCount = rhs.mCount;
-            SharedBuffer::sharedBuffer(mStorage)->acquire();
+            SharedBuffer::bufferFromData(mStorage)->acquire();
         } else {
             mStorage = 0;
             mCount = 0;
@@ -85,7 +85,7 @@ VectorImpl& VectorImpl::operator = (const VectorImpl& rhs)
 void* VectorImpl::editArrayImpl()
 {
     if (mStorage) {
-        SharedBuffer* sb = SharedBuffer::sharedBuffer(mStorage)->attemptEdit();
+        SharedBuffer* sb = SharedBuffer::bufferFromData(mStorage)->attemptEdit();
         if (sb == 0) {
             sb = SharedBuffer::alloc(capacity() * mItemSize);
             if (sb) {
@@ -101,7 +101,7 @@ void* VectorImpl::editArrayImpl()
 size_t VectorImpl::capacity() const
 {
     if (mStorage) {
-        return SharedBuffer::sharedBuffer(mStorage)->size() / mItemSize;
+        return SharedBuffer::bufferFromData(mStorage)->size() / mItemSize;
     }
     return 0;
 }
@@ -346,7 +346,7 @@ ssize_t VectorImpl::setCapacity(size_t new_capacity)
 void VectorImpl::release_storage()
 {
     if (mStorage) {
-        const SharedBuffer* sb = SharedBuffer::sharedBuffer(mStorage);
+        const SharedBuffer* sb = SharedBuffer::bufferFromData(mStorage);
         if (sb->release(SharedBuffer::eKeepStorage) == 1) {
             _do_destroy(mStorage, mCount);
             SharedBuffer::dealloc(sb);
@@ -372,7 +372,7 @@ void* VectorImpl::_grow(size_t where, size_t amount)
             (mFlags & HAS_TRIVIAL_COPY) &&
             (mFlags & HAS_TRIVIAL_DTOR))
         {
-            const SharedBuffer* cur_sb = SharedBuffer::sharedBuffer(mStorage);
+            const SharedBuffer* cur_sb = SharedBuffer::bufferFromData(mStorage);
             SharedBuffer* sb = cur_sb->editResize(new_capacity * mItemSize);
             mStorage = sb->data();
         } else {
@@ -424,7 +424,7 @@ void VectorImpl::_shrink(size_t where, size_t amount)
             (mFlags & HAS_TRIVIAL_COPY) &&
             (mFlags & HAS_TRIVIAL_DTOR))
         {
-            const SharedBuffer* cur_sb = SharedBuffer::sharedBuffer(mStorage);
+            const SharedBuffer* cur_sb = SharedBuffer::bufferFromData(mStorage);
             SharedBuffer* sb = cur_sb->editResize(new_capacity * mItemSize);
             mStorage = sb->data();
         } else {