XERCESC-2138: Drop XERCES_HAS_CPP_NAMESPACE check
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4254f89..346f1a2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -132,7 +132,6 @@
 include(XercesVolatile)
 include(XercesLString)
 include(XercesMFC)
-include(XercesNamespaces)
 include(XercesStdLibs)
 include(XercesStdNamespace)
 include(XercesSSE2)
diff --git a/cmake/XercesNamespaces.cmake b/cmake/XercesNamespaces.cmake
deleted file mode 100644
index 1acbd79..0000000
--- a/cmake/XercesNamespaces.cmake
+++ /dev/null
@@ -1,37 +0,0 @@
-# CMake build for xerces-c
-#
-# Written by Roger Leigh <rleigh@codelibre.net>
-#
-# Licensed to the Apache Software Foundation (ASF) under one or more
-# contributor license agreements.  See the NOTICE file distributed with
-# this work for additional information regarding copyright ownership.
-# The ASF licenses this file to You under the Apache License, Version 2.0
-# (the "License"); you may not use this file except in compliance with
-# the License.  You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# namespace keyword
-
-include(CheckCXXSourceCompiles)
-
-check_cxx_source_compiles("
-namespace Outer {
-  namespace Inner {
-    int i = 0;
-  }
-}
-
-int main() {
-  using namespace Outer::Inner;
-  return i;
-}"
-  HAVE_NAMESPACES)
-
-set(XERCES_HAS_CPP_NAMESPACE ${HAVE_NAMESPACES})
diff --git a/cmake/XercesStdLibs.cmake b/cmake/XercesStdLibs.cmake
index c898d03..23afe06 100644
--- a/cmake/XercesStdLibs.cmake
+++ b/cmake/XercesStdLibs.cmake
@@ -20,26 +20,16 @@
 # C++ standard library includes
 
 include(CheckCXXSourceCompiles)
-include(XercesNamespaces)
-
-set(CMAKE_REQUIRED_DEFINITIONS_SAVE ${CMAKE_REQUIRED_DEFINITIONS})
-if(HAVE_NAMESPACES)
-  set(CMAKE_REQUIRED_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} -DHAVE_NAMESPACES)
-endif()
 
 check_cxx_source_compiles("
 #include <map>
 #include <iomanip>
 #include <cmath>
-#ifdef HAVE_NAMESPACES
 using namespace std;
-#endif
 
 int main() {
   return 0;
 }"
   HAVE_STD_LIBS)
 
-set(CMAKE_REQUIRED_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS_SAVE})
-
 set(XERCES_NEW_IOSTREAMS ${HAVE_STD_LIBS})
diff --git a/config.h.cmake.in b/config.h.cmake.in
index 4972d29..8c80a52 100644
--- a/config.h.cmake.in
+++ b/config.h.cmake.in
@@ -144,9 +144,6 @@
 /* Define to 1 if you have the `memset' function. */
 #cmakedefine HAVE_MEMSET 1
 
-/* define if the compiler implements namespaces */
-#cmakedefine HAVE_NAMESPACES 1
-
 /* Define to 1 if you have the <netdb.h> header file. */
 #cmakedefine HAVE_NETDB_H 1
 
@@ -343,9 +340,6 @@
 /* Define if DLL symbols should be exported */
 #cmakedefine XERCES_DLL_EXPORT 1
 
-/* Define if namespaces is supported by the compiler */
-#cmakedefine XERCES_HAS_CPP_NAMESPACE 1
-
 /* Define to have SSE2 instruction support detected at runtime using __cpuid
    */
 #cmakedefine XERCES_HAVE_CPUID_INTRINSIC 1
diff --git a/configure.ac b/configure.ac
index 1a38ec8..7738cad 100644
--- a/configure.ac
+++ b/configure.ac
@@ -153,7 +153,6 @@
 XERCES_INT_TYPES
 
 AC_CXX_HAVE_BOOL
-AC_CXX_HAVE_NAMESPACES
 AC_CXX_HAVE_STD_NAMESPACE
 AC_CXX_HAVE_STD_LIBS
 AC_CXX_HAVE_LSTRING
@@ -523,9 +522,6 @@
 	AC_DEFINE([XERCES_SSIZE_T], [long], [Define as the appropriate ssize_t type])
 	AC_DEFINE([XERCES_SSIZE_MAX], [LONG_MAX], [Define as the appropriate SSIZE_MAX macro]))
 
-AS_IF([test x$ac_cv_cxx_have_namespaces = xyes],
-	AC_DEFINE([XERCES_HAS_CPP_NAMESPACE], 1, [Define if namespaces is supported by the compiler]))
-
 AS_IF([test x$ac_cv_cxx_have_std_namespace = xyes],
 	AC_DEFINE([XERCES_STD_NAMESPACE], 1, [Define if the std namespace is supported]))
 
diff --git a/m4/cxx_have_namespaces.m4 b/m4/cxx_have_namespaces.m4
deleted file mode 100644
index 70dcc14..0000000
--- a/m4/cxx_have_namespaces.m4
+++ /dev/null
@@ -1,25 +0,0 @@
-dnl @synopsis AC_CXX_HAVE_NAMESPACES
-dnl
-dnl If the compiler can prevent names clashes using namespaces, define
-dnl HAVE_NAMESPACES.
-dnl
-dnl @category Cxx
-dnl @author Todd Veldhuizen
-dnl @author Luc Maisonobe <luc@spaceroots.org>
-dnl @version 2004-02-04
-dnl @license AllPermissive
-
-AC_DEFUN([AC_CXX_HAVE_NAMESPACES],
-[AC_CACHE_CHECK(whether the compiler implements namespaces,
-ac_cv_cxx_have_namespaces,
-[AC_LANG_SAVE
- AC_LANG_CPLUSPLUS
- AC_TRY_COMPILE([namespace Outer { namespace Inner { int i = 0; }}],
-                [using namespace Outer::Inner; return i;],
- ac_cv_cxx_have_namespaces=yes, ac_cv_cxx_have_namespaces=no)
- AC_LANG_RESTORE
-])
-if test "$ac_cv_cxx_have_namespaces" = yes; then
-  AC_DEFINE(HAVE_NAMESPACES,,[define if the compiler implements namespaces])
-fi
-])
diff --git a/m4/cxx_have_std_libs.m4 b/m4/cxx_have_std_libs.m4
index 28a28b3..0175217 100644
--- a/m4/cxx_have_std_libs.m4
+++ b/m4/cxx_have_std_libs.m4
@@ -13,16 +13,14 @@
 AC_DEFUN([AC_CXX_HAVE_STD_LIBS],
 [AC_CACHE_CHECK(whether the compiler supports ISO C++ standard library,
 ac_cv_cxx_have_std_libs,
-[AC_REQUIRE([AC_CXX_HAVE_NAMESPACES])
+[
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  AC_TRY_COMPILE([#include <iostream>
 #include <map>
 #include <iomanip>
 #include <cmath>
-#ifdef HAVE_NAMESPACES
-using namespace std;
-#endif],[return 0;],
+using namespace std;],[return 0;],
  ac_cv_cxx_have_std_libs=yes, ac_cv_cxx_have_std_libs=no)
  AC_LANG_RESTORE
 ])
diff --git a/src/xercesc/util/XercesDefs.hpp b/src/xercesc/util/XercesDefs.hpp
index 8071260..e6cb776 100644
--- a/src/xercesc/util/XercesDefs.hpp
+++ b/src/xercesc/util/XercesDefs.hpp
@@ -100,20 +100,13 @@
 // ---------------------------------------------------------------------------
 // Define namespace symbols if the compiler supports it.
 // ---------------------------------------------------------------------------
-#if defined(XERCES_HAS_CPP_NAMESPACE)
-    #define XERCES_CPP_NAMESPACE_BEGIN namespace XERCES_CPP_NAMESPACE {
-    #define XERCES_CPP_NAMESPACE_END  }
-    #define XERCES_CPP_NAMESPACE_USE using namespace XERCES_CPP_NAMESPACE;
-    #define XERCES_CPP_NAMESPACE_QUALIFIER XERCES_CPP_NAMESPACE::
+#define XERCES_CPP_NAMESPACE_BEGIN namespace XERCES_CPP_NAMESPACE {
+#define XERCES_CPP_NAMESPACE_END  }
+#define XERCES_CPP_NAMESPACE_USE using namespace XERCES_CPP_NAMESPACE;
+#define XERCES_CPP_NAMESPACE_QUALIFIER XERCES_CPP_NAMESPACE::
 
-    namespace XERCES_CPP_NAMESPACE { }
-    namespace xercesc = XERCES_CPP_NAMESPACE;
-#else
-    #define XERCES_CPP_NAMESPACE_BEGIN
-    #define XERCES_CPP_NAMESPACE_END
-    #define XERCES_CPP_NAMESPACE_USE
-    #define XERCES_CPP_NAMESPACE_QUALIFIER
-#endif
+namespace XERCES_CPP_NAMESPACE { }
+namespace xercesc = XERCES_CPP_NAMESPACE;
 
 #if defined(XERCES_STD_NAMESPACE)
 	#define XERCES_USING_STD(NAME) using std :: NAME;
diff --git a/src/xercesc/util/Xerces_autoconf_config.hpp.cmake.in b/src/xercesc/util/Xerces_autoconf_config.hpp.cmake.in
index 0d99e08..e6aa7be 100644
--- a/src/xercesc/util/Xerces_autoconf_config.hpp.cmake.in
+++ b/src/xercesc/util/Xerces_autoconf_config.hpp.cmake.in
@@ -67,7 +67,6 @@
 #define XERCES_SIZE_T @XERCES_SIZE_T@
 #define XERCES_SSIZE_T @XERCES_SSIZE_T@
 
-#cmakedefine XERCES_HAS_CPP_NAMESPACE 1
 #cmakedefine XERCES_STD_NAMESPACE 1
 #cmakedefine XERCES_NEW_IOSTREAMS 1
 #cmakedefine XERCES_NO_NATIVE_BOOL 1
diff --git a/src/xercesc/util/Xerces_autoconf_config.hpp.in b/src/xercesc/util/Xerces_autoconf_config.hpp.in
index aaf70fb..6f777ea 100644
--- a/src/xercesc/util/Xerces_autoconf_config.hpp.in
+++ b/src/xercesc/util/Xerces_autoconf_config.hpp.in
@@ -68,7 +68,6 @@
 #undef XERCES_SIZE_T
 #undef XERCES_SSIZE_T
 
-#undef XERCES_HAS_CPP_NAMESPACE
 #undef XERCES_STD_NAMESPACE
 #undef XERCES_NEW_IOSTREAMS
 #undef XERCES_NO_NATIVE_BOOL