   -Wold-style-cast
   -Woverloaded-virtual
   -Wpointer-arith
-@@ -23,17 +24,19 @@ set(CXX_FLAGS
+@@ -24,17 +25,19 @@ set(CXX_FLAGS
   -march=native
   # -MMD
   # -std=c++0x

 set(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
 set(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR}/lib)
 
@@ -44,6 +47,8 @@ find_path(CARES_INCLUDE_DIR ares.h)
 find_library(CARES_LIBRARY NAMES cares)
 
 include_directories(${Boost_INCLUDE_DIRS})
+include_directories(/usr/lib/gcc/x86_64-linux-gnu/4.4/include/)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2c8880a..ea1432a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,13 +9,14 @@ endif()
 set(CXX_FLAGS
  -g
  # -DVALGRIND
- # -DMUDUO_STD_STRING
+ -DMUDUO_STD_STRING
  -D_FILE_OFFSET_BITS=64
  -Wall
  -Wextra
- -Werror
