THRIFT-1740 Make C++ library build on OS X and iOS
Patch: Ben Craig
minor modification by Roger Meier


git-svn-id: https://svn.apache.org/repos/asf/thrift/trunk@1410127 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/cpp/src/thrift/protocol/TDenseProtocol.cpp b/lib/cpp/src/thrift/protocol/TDenseProtocol.cpp
index 1eb444b..4fbfc13 100644
--- a/lib/cpp/src/thrift/protocol/TDenseProtocol.cpp
+++ b/lib/cpp/src/thrift/protocol/TDenseProtocol.cpp
@@ -253,8 +253,8 @@
   // Back up one step before writing.
   pos++;
 
-  trans_->write(buf+pos, sizeof(buf) - pos);
-  return sizeof(buf) - pos;
+  trans_->write(buf+pos, static_cast<uint32_t>(sizeof(buf) - pos));
+  return static_cast<uint32_t>(sizeof(buf) - pos);
 }