diff --git a/aclocal/ax_boost_base.m4 b/aclocal/ax_boost_base.m4
index b496020..19c71b6 100644
--- a/aclocal/ax_boost_base.m4
+++ b/aclocal/ax_boost_base.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#       http://www.gnu.org/software/autoconf-archive/ax_boost_base.html
+#      https://www.gnu.org/software/autoconf-archive/ax_boost_base.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -33,7 +33,15 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 23
+#serial 42
+
+# example boost program (need to pass version)
+m4_define([_AX_BOOST_BASE_PROGRAM],
+          [AC_LANG_PROGRAM([[
+#include <boost/version.hpp>
+]],[[
+(void) ((void)sizeof(char[1 - 2*!!((BOOST_VERSION) < ($1))]));
+]])])
 
 AC_DEFUN([AX_BOOST_BASE],
 [
@@ -44,101 +52,121 @@
      or disable it (ARG=no)
      @<:@ARG=yes@:>@ ])],
     [
-    if test "$withval" = "no"; then
-        want_boost="no"
-    elif test "$withval" = "yes"; then
-        want_boost="yes"
-        ac_boost_path=""
-    else
-        want_boost="yes"
-        ac_boost_path="$withval"
-    fi
+     AS_CASE([$withval],
+       [no],[want_boost="no";_AX_BOOST_BASE_boost_path=""],
+       [yes],[want_boost="yes";_AX_BOOST_BASE_boost_path=""],
+       [want_boost="yes";_AX_BOOST_BASE_boost_path="$withval"])
     ],
     [want_boost="yes"])
 
 
 AC_ARG_WITH([boost-libdir],
-        AS_HELP_STRING([--with-boost-libdir=LIB_DIR],
-        [Force given directory for boost libraries. Note that this will override library path detection, so use this parameter only if default library detection fails and you know exactly where your boost libraries are located.]),
-        [
-        if test -d "$withval"
-        then
-                ac_boost_lib_path="$withval"
-        else
-                AC_MSG_ERROR(--with-boost-libdir expected directory name)
-        fi
-        ],
-        [ac_boost_lib_path=""]
-)
+  [AS_HELP_STRING([--with-boost-libdir=LIB_DIR],
+    [Force given directory for boost libraries.
+     Note that this will override library path detection,
+     so use this parameter only if default library detection fails
+     and you know exactly where your boost libraries are located.])],
+  [
+   AS_IF([test -d "$withval"],
+         [_AX_BOOST_BASE_boost_lib_path="$withval"],
+    [AC_MSG_ERROR([--with-boost-libdir expected directory name])])
+  ],
+  [_AX_BOOST_BASE_boost_lib_path=""])
 
-if test "x$want_boost" = "xyes"; then
-    boost_lib_version_req=ifelse([$1], ,1.20.0,$1)
-    boost_lib_version_req_shorten=`expr $boost_lib_version_req : '\([[0-9]]*\.[[0-9]]*\)'`
-    boost_lib_version_req_major=`expr $boost_lib_version_req : '\([[0-9]]*\)'`
-    boost_lib_version_req_minor=`expr $boost_lib_version_req : '[[0-9]]*\.\([[0-9]]*\)'`
-    boost_lib_version_req_sub_minor=`expr $boost_lib_version_req : '[[0-9]]*\.[[0-9]]*\.\([[0-9]]*\)'`
-    if test "x$boost_lib_version_req_sub_minor" = "x" ; then
-        boost_lib_version_req_sub_minor="0"
-        fi
-    WANT_BOOST_VERSION=`expr $boost_lib_version_req_major \* 100000 \+  $boost_lib_version_req_minor \* 100 \+ $boost_lib_version_req_sub_minor`
-    AC_MSG_CHECKING(for boostlib >= $boost_lib_version_req)
+BOOST_LDFLAGS=""
+BOOST_CPPFLAGS=""
+AS_IF([test "x$want_boost" = "xyes"],
+      [_AX_BOOST_BASE_RUNDETECT([$1],[$2],[$3])])
+AC_SUBST(BOOST_CPPFLAGS)
+AC_SUBST(BOOST_LDFLAGS)
+])
+
+
+# convert a version string in $2 to numeric and affect to polymorphic var $1
+AC_DEFUN([_AX_BOOST_BASE_TONUMERICVERSION],[
+  AS_IF([test "x$2" = "x"],[_AX_BOOST_BASE_TONUMERICVERSION_req="1.20.0"],[_AX_BOOST_BASE_TONUMERICVERSION_req="$2"])
+  _AX_BOOST_BASE_TONUMERICVERSION_req_shorten=`expr $_AX_BOOST_BASE_TONUMERICVERSION_req : '\([[0-9]]*\.[[0-9]]*\)'`
+  _AX_BOOST_BASE_TONUMERICVERSION_req_major=`expr $_AX_BOOST_BASE_TONUMERICVERSION_req : '\([[0-9]]*\)'`
+  AS_IF([test "x$_AX_BOOST_BASE_TONUMERICVERSION_req_major" = "x"],
+        [AC_MSG_ERROR([You should at least specify libboost major version])])
+  _AX_BOOST_BASE_TONUMERICVERSION_req_minor=`expr $_AX_BOOST_BASE_TONUMERICVERSION_req : '[[0-9]]*\.\([[0-9]]*\)'`
+  AS_IF([test "x$_AX_BOOST_BASE_TONUMERICVERSION_req_minor" = "x"],
+        [_AX_BOOST_BASE_TONUMERICVERSION_req_minor="0"])
+  _AX_BOOST_BASE_TONUMERICVERSION_req_sub_minor=`expr $_AX_BOOST_BASE_TONUMERICVERSION_req : '[[0-9]]*\.[[0-9]]*\.\([[0-9]]*\)'`
+  AS_IF([test "X$_AX_BOOST_BASE_TONUMERICVERSION_req_sub_minor" = "X"],
+        [_AX_BOOST_BASE_TONUMERICVERSION_req_sub_minor="0"])
+  _AX_BOOST_BASE_TONUMERICVERSION_RET=`expr $_AX_BOOST_BASE_TONUMERICVERSION_req_major \* 100000 \+  $_AX_BOOST_BASE_TONUMERICVERSION_req_minor \* 100 \+ $_AX_BOOST_BASE_TONUMERICVERSION_req_sub_minor`
+  AS_VAR_SET($1,$_AX_BOOST_BASE_TONUMERICVERSION_RET)
+])
+
+dnl Run the detection of boost should be run only if $want_boost
+AC_DEFUN([_AX_BOOST_BASE_RUNDETECT],[
+    _AX_BOOST_BASE_TONUMERICVERSION(WANT_BOOST_VERSION,[$1])
     succeeded=no
 
+
+    AC_REQUIRE([AC_CANONICAL_HOST])
     dnl On 64-bit systems check for system libraries in both lib64 and lib.
     dnl The former is specified by FHS, but e.g. Debian does not adhere to
     dnl this (as it rises problems for generic multi-arch support).
     dnl The last entry in the list is chosen by default when no libraries
     dnl are found, e.g. when only header-only libraries are installed!
-    libsubdirs="lib"
-    ax_arch=`uname -m`
-    case $ax_arch in
-      x86_64|ppc64|s390x|sparc64|aarch64)
-        libsubdirs="lib64 lib lib64"
-        ;;
-    esac
+    AS_CASE([${host_cpu}],
+      [x86_64],[libsubdirs="lib64 libx32 lib lib64"],
+      [ppc64|s390x|sparc64|aarch64|ppc64le],[libsubdirs="lib64 lib lib64"],
+      [libsubdirs="lib"],
+    )
 
     dnl allow for real multi-arch paths e.g. /usr/lib/x86_64-linux-gnu. Give
     dnl them priority over the other paths since, if libs are found there, they
     dnl are almost assuredly the ones desired.
-    AC_REQUIRE([AC_CANONICAL_HOST])
-    libsubdirs="lib/${host_cpu}-${host_os} $libsubdirs"
-
-    case ${host_cpu} in
-      i?86)
-        libsubdirs="lib/i386-${host_os} $libsubdirs"
-        ;;
-    esac
+    AS_CASE([${host_cpu}],
+      [i?86],[multiarch_libsubdir="lib/i386-${host_os}"],
+      [multiarch_libsubdir="lib/${host_cpu}-${host_os}"]
+    )
 
     dnl first we check the system location for boost libraries
     dnl this location ist chosen if boost libraries are installed with the --layout=system option
     dnl or if you install boost with RPM
-    if test "$ac_boost_path" != ""; then
-        BOOST_CPPFLAGS="-I$ac_boost_path/include"
-        for ac_boost_path_tmp in $libsubdirs; do
-                if test -d "$ac_boost_path"/"$ac_boost_path_tmp" ; then
-                        BOOST_LDFLAGS="-L$ac_boost_path/$ac_boost_path_tmp"
-                        break
-                fi
-        done
-    elif test "$cross_compiling" != yes; then
-        for ac_boost_path_tmp in $lt_sysroot/usr $lt_sysroot/usr/local $lt_sysroot/opt $lt_sysroot/opt/local ; do
-            if test -d "$ac_boost_path_tmp/include/boost" && test -r "$ac_boost_path_tmp/include/boost"; then
-                for libsubdir in $libsubdirs ; do
-                    if ls "$ac_boost_path_tmp/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
+    AS_IF([test "x$_AX_BOOST_BASE_boost_path" != "x"],[
+        AC_MSG_CHECKING([for boostlib >= $1 ($WANT_BOOST_VERSION) includes in "$_AX_BOOST_BASE_boost_path/include"])
+         AS_IF([test -d "$_AX_BOOST_BASE_boost_path/include" && test -r "$_AX_BOOST_BASE_boost_path/include"],[
+           AC_MSG_RESULT([yes])
+           BOOST_CPPFLAGS="-I$_AX_BOOST_BASE_boost_path/include"
+           for _AX_BOOST_BASE_boost_path_tmp in $multiarch_libsubdir $libsubdirs; do
+                AC_MSG_CHECKING([for boostlib >= $1 ($WANT_BOOST_VERSION) lib path in "$_AX_BOOST_BASE_boost_path/$_AX_BOOST_BASE_boost_path_tmp"])
+                AS_IF([test -d "$_AX_BOOST_BASE_boost_path/$_AX_BOOST_BASE_boost_path_tmp" && test -r "$_AX_BOOST_BASE_boost_path/$_AX_BOOST_BASE_boost_path_tmp" ],[
+                        AC_MSG_RESULT([yes])
+                        BOOST_LDFLAGS="-L$_AX_BOOST_BASE_boost_path/$_AX_BOOST_BASE_boost_path_tmp";
+                        break;
+                ],
+      [AC_MSG_RESULT([no])])
+           done],[
+      AC_MSG_RESULT([no])])
+    ],[
+        if test X"$cross_compiling" = Xyes; then
+            search_libsubdirs=$multiarch_libsubdir
+        else
+            search_libsubdirs="$multiarch_libsubdir $libsubdirs"
+        fi
+        for _AX_BOOST_BASE_boost_path_tmp in /usr /usr/local /opt /opt/local ; do
+            if test -d "$_AX_BOOST_BASE_boost_path_tmp/include/boost" && test -r "$_AX_BOOST_BASE_boost_path_tmp/include/boost" ; then
+                for libsubdir in $search_libsubdirs ; do
+                    if ls "$_AX_BOOST_BASE_boost_path_tmp/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
                 done
-                BOOST_LDFLAGS="-L$ac_boost_path_tmp/$libsubdir"
-                BOOST_CPPFLAGS="-I$ac_boost_path_tmp/include"
+                BOOST_LDFLAGS="-L$_AX_BOOST_BASE_boost_path_tmp/$libsubdir"
+                BOOST_CPPFLAGS="-I$_AX_BOOST_BASE_boost_path_tmp/include"
                 break;
             fi
         done
-    fi
+    ])
 
     dnl overwrite ld flags if we have required special directory with
     dnl --with-boost-libdir parameter
-    if test "$ac_boost_lib_path" != ""; then
-       BOOST_LDFLAGS="-L$ac_boost_lib_path"
-    fi
+    AS_IF([test "x$_AX_BOOST_BASE_boost_lib_path" != "x"],
+          [BOOST_LDFLAGS="-L$_AX_BOOST_BASE_boost_lib_path"])
 
+    AC_MSG_CHECKING([for boostlib >= $1 ($WANT_BOOST_VERSION)])
     CPPFLAGS_SAVED="$CPPFLAGS"
     CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
     export CPPFLAGS
@@ -149,15 +177,7 @@
 
     AC_REQUIRE([AC_PROG_CXX])
     AC_LANG_PUSH(C++)
-        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-    @%:@include <boost/version.hpp>
-    ]], [[
-    #if BOOST_VERSION >= $WANT_BOOST_VERSION
-    // Everything is okay
-    #else
-    #  error Boost version is too old
-    #endif
-    ]])],[
+        AC_COMPILE_IFELSE([_AX_BOOST_BASE_PROGRAM($WANT_BOOST_VERSION)],[
         AC_MSG_RESULT(yes)
     succeeded=yes
     found_system=yes
@@ -169,30 +189,50 @@
 
     dnl if we found no boost with system layout we search for boost libraries
     dnl built and installed without the --layout=system option or for a staged(not installed) version
-    if test "x$succeeded" != "xyes"; then
+    if test "x$succeeded" != "xyes" ; then
+        CPPFLAGS="$CPPFLAGS_SAVED"
+        LDFLAGS="$LDFLAGS_SAVED"
+        BOOST_CPPFLAGS=
+        if test -z "$_AX_BOOST_BASE_boost_lib_path" ; then
+            BOOST_LDFLAGS=
+        fi
         _version=0
-        if test "$ac_boost_path" != ""; then
-            if test -d "$ac_boost_path" && test -r "$ac_boost_path"; then
-                for i in `ls -d $ac_boost_path/include/boost-* 2>/dev/null`; do
-                    _version_tmp=`echo $i | sed "s#$ac_boost_path##" | sed 's/\/include\/boost-//' | sed 's/_/./'`
+        if test -n "$_AX_BOOST_BASE_boost_path" ; then
+            if test -d "$_AX_BOOST_BASE_boost_path" && test -r "$_AX_BOOST_BASE_boost_path"; then
+                for i in `ls -d $_AX_BOOST_BASE_boost_path/include/boost-* 2>/dev/null`; do
+                    _version_tmp=`echo $i | sed "s#$_AX_BOOST_BASE_boost_path##" | sed 's/\/include\/boost-//' | sed 's/_/./'`
                     V_CHECK=`expr $_version_tmp \> $_version`
-                    if test "$V_CHECK" = "1" ; then
+                    if test "x$V_CHECK" = "x1" ; then
                         _version=$_version_tmp
                     fi
                     VERSION_UNDERSCORE=`echo $_version | sed 's/\./_/'`
-                    BOOST_CPPFLAGS="-I$ac_boost_path/include/boost-$VERSION_UNDERSCORE"
+                    BOOST_CPPFLAGS="-I$_AX_BOOST_BASE_boost_path/include/boost-$VERSION_UNDERSCORE"
                 done
+                dnl if nothing found search for layout used in Windows distributions
+                if test -z "$BOOST_CPPFLAGS"; then
+                    if test -d "$_AX_BOOST_BASE_boost_path/boost" && test -r "$_AX_BOOST_BASE_boost_path/boost"; then
+                        BOOST_CPPFLAGS="-I$_AX_BOOST_BASE_boost_path"
+                    fi
+                fi
+                dnl if we found something and BOOST_LDFLAGS was unset before
+                dnl (because "$_AX_BOOST_BASE_boost_lib_path" = ""), set it here.
+                if test -n "$BOOST_CPPFLAGS" && test -z "$BOOST_LDFLAGS"; then
+                    for libsubdir in $libsubdirs ; do
+                        if ls "$_AX_BOOST_BASE_boost_path/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
+                    done
+                    BOOST_LDFLAGS="-L$_AX_BOOST_BASE_boost_path/$libsubdir"
+                fi
             fi
         else
-            if test "$cross_compiling" != yes; then
-                for ac_boost_path in $lt_sysroot/usr $lt_sysroot/usr/local $lt_sysroot/opt $lt_sysroot/opt/local ; do
-                    if test -d "$ac_boost_path" && test -r "$ac_boost_path"; then
-                        for i in `ls -d $ac_boost_path/include/boost-* 2>/dev/null`; do
-                            _version_tmp=`echo $i | sed "s#$ac_boost_path##" | sed 's/\/include\/boost-//' | sed 's/_/./'`
+            if test "x$cross_compiling" != "xyes" ; then
+                for _AX_BOOST_BASE_boost_path in /usr /usr/local /opt /opt/local ; do
+                    if test -d "$_AX_BOOST_BASE_boost_path" && test -r "$_AX_BOOST_BASE_boost_path" ; then
+                        for i in `ls -d $_AX_BOOST_BASE_boost_path/include/boost-* 2>/dev/null`; do
+                            _version_tmp=`echo $i | sed "s#$_AX_BOOST_BASE_boost_path##" | sed 's/\/include\/boost-//' | sed 's/_/./'`
                             V_CHECK=`expr $_version_tmp \> $_version`
-                            if test "$V_CHECK" = "1" ; then
+                            if test "x$V_CHECK" = "x1" ; then
                                 _version=$_version_tmp
-                                best_path=$ac_boost_path
+                                best_path=$_AX_BOOST_BASE_boost_path
                             fi
                         done
                     fi
@@ -200,7 +240,7 @@
 
                 VERSION_UNDERSCORE=`echo $_version | sed 's/\./_/'`
                 BOOST_CPPFLAGS="-I$best_path/include/boost-$VERSION_UNDERSCORE"
-                if test "$ac_boost_lib_path" = ""; then
+                if test -z "$_AX_BOOST_BASE_boost_lib_path" ; then
                     for libsubdir in $libsubdirs ; do
                         if ls "$best_path/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
                     done
@@ -208,7 +248,7 @@
                 fi
             fi
 
-            if test "x$BOOST_ROOT" != "x"; then
+            if test -n "$BOOST_ROOT" ; then
                 for libsubdir in $libsubdirs ; do
                     if ls "$BOOST_ROOT/stage/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
                 done
@@ -217,7 +257,7 @@
                     stage_version=`echo $version_dir | sed 's/boost_//' | sed 's/_/./g'`
                         stage_version_shorten=`expr $stage_version : '\([[0-9]]*\.[[0-9]]*\)'`
                     V_CHECK=`expr $stage_version_shorten \>\= $_version`
-                    if test "$V_CHECK" = "1" -a "$ac_boost_lib_path" = "" ; then
+                    if test "x$V_CHECK" = "x1" && test -z "$_AX_BOOST_BASE_boost_lib_path" ; then
                         AC_MSG_NOTICE(We will use a staged boost library from $BOOST_ROOT)
                         BOOST_CPPFLAGS="-I$BOOST_ROOT"
                         BOOST_LDFLAGS="-L$BOOST_ROOT/stage/$libsubdir"
@@ -232,15 +272,7 @@
         export LDFLAGS
 
         AC_LANG_PUSH(C++)
-            AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-        @%:@include <boost/version.hpp>
-        ]], [[
-        #if BOOST_VERSION >= $WANT_BOOST_VERSION
-        // Everything is okay
-        #else
-        #  error Boost version is too old
-        #endif
-        ]])],[
+            AC_COMPILE_IFELSE([_AX_BOOST_BASE_PROGRAM($WANT_BOOST_VERSION)],[
             AC_MSG_RESULT(yes)
         succeeded=yes
         found_system=yes
@@ -249,17 +281,15 @@
         AC_LANG_POP([C++])
     fi
 
-    if test "$succeeded" != "yes" ; then
-        if test "$_version" = "0" ; then
-            AC_MSG_NOTICE([[We could not detect the boost libraries (version $boost_lib_version_req_shorten or higher). If you have a staged boost library (still not installed) please specify \$BOOST_ROOT in your environment and do not give a PATH to --with-boost option.  If you are sure you have boost installed, then check your version number looking in <boost/version.hpp>. See http://randspringer.de/boost for more documentation.]])
+    if test "x$succeeded" != "xyes" ; then
+        if test "x$_version" = "x0" ; then
+            AC_MSG_NOTICE([[We could not detect the boost libraries (version $1 or higher). If you have a staged boost library (still not installed) please specify \$BOOST_ROOT in your environment and do not give a PATH to --with-boost option.  If you are sure you have boost installed, then check your version number looking in <boost/version.hpp>. See http://randspringer.de/boost for more documentation.]])
         else
             AC_MSG_NOTICE([Your boost libraries seems to old (version $_version).])
         fi
         # execute ACTION-IF-NOT-FOUND (if present):
         ifelse([$3], , :, [$3])
     else
-        AC_SUBST(BOOST_CPPFLAGS)
-        AC_SUBST(BOOST_LDFLAGS)
         AC_DEFINE(HAVE_BOOST,,[define if the Boost library is available])
         # execute ACTION-IF-FOUND (if present):
         ifelse([$2], , :, [$2])
@@ -267,6 +297,5 @@
 
     CPPFLAGS="$CPPFLAGS_SAVED"
     LDFLAGS="$LDFLAGS_SAVED"
-fi
 
 ])
diff --git a/aclocal/ax_cxx_compile_stdcxx.m4 b/aclocal/ax_cxx_compile_stdcxx.m4
new file mode 100644
index 0000000..5032bba
--- /dev/null
+++ b/aclocal/ax_cxx_compile_stdcxx.m4
@@ -0,0 +1,982 @@
+# ===========================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_CXX_COMPILE_STDCXX(VERSION, [ext|noext], [mandatory|optional])
+#
+# DESCRIPTION
+#
+#   Check for baseline language coverage in the compiler for the specified
+#   version of the C++ standard.  If necessary, add switches to CXX and
+#   CXXCPP to enable support.  VERSION may be '11' (for the C++11 standard)
+#   or '14' (for the C++14 standard).
+#
+#   The second argument, if specified, indicates whether you insist on an
+#   extended mode (e.g. -std=gnu++11) or a strict conformance mode (e.g.
+#   -std=c++11).  If neither is specified, you get whatever works, with
+#   preference for an extended mode.
+#
+#   The third argument, if specified 'mandatory' or if left unspecified,
+#   indicates that baseline support for the specified C++ standard is
+#   required and that the macro should error out if no mode with that
+#   support is found.  If specified 'optional', then configuration proceeds
+#   regardless, after defining HAVE_CXX${VERSION} if and only if a
+#   supporting mode is found.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Benjamin Kosnik <bkoz@redhat.com>
+#   Copyright (c) 2012 Zack Weinberg <zackw@panix.com>
+#   Copyright (c) 2013 Roy Stogner <roystgnr@ices.utexas.edu>
+#   Copyright (c) 2014, 2015 Google Inc.; contributed by Alexey Sokolov <sokolov@google.com>
+#   Copyright (c) 2015 Paul Norman <penorman@mac.com>
+#   Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu>
+#   Copyright (c) 2016 Krzesimir Nowak <qdlacz@gmail.com>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
+
+#serial 7
+
+dnl  This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro
+dnl  (serial version number 13).
+
+AX_REQUIRE_DEFINED([AC_MSG_WARN])
+AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
+  m4_if([$1], [11], [ax_cxx_compile_alternatives="11 0x"],
+        [$1], [14], [ax_cxx_compile_alternatives="14 1y"],
+        [$1], [17], [ax_cxx_compile_alternatives="17 1z"],
+        [m4_fatal([invalid first argument `$1' to AX_CXX_COMPILE_STDCXX])])dnl
+  m4_if([$2], [], [],
+        [$2], [ext], [],
+        [$2], [noext], [],
+        [m4_fatal([invalid second argument `$2' to AX_CXX_COMPILE_STDCXX])])dnl
+  m4_if([$3], [], [ax_cxx_compile_cxx$1_required=true],
+        [$3], [mandatory], [ax_cxx_compile_cxx$1_required=true],
+        [$3], [optional], [ax_cxx_compile_cxx$1_required=false],
+        [m4_fatal([invalid third argument `$3' to AX_CXX_COMPILE_STDCXX])])
+  AC_LANG_PUSH([C++])dnl
+  ac_success=no
+  AC_CACHE_CHECK(whether $CXX supports C++$1 features by default,
+  ax_cv_cxx_compile_cxx$1,
+  [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])],
+    [ax_cv_cxx_compile_cxx$1=yes],
+    [ax_cv_cxx_compile_cxx$1=no])])
+  if test x$ax_cv_cxx_compile_cxx$1 = xyes; then
+    ac_success=yes
+  fi
+
+  m4_if([$2], [noext], [], [dnl
+  if test x$ac_success = xno; then
+    for alternative in ${ax_cxx_compile_alternatives}; do
+      switch="-std=gnu++${alternative}"
+      cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch])
+      AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch,
+                     $cachevar,
+        [ac_save_CXX="$CXX"
+         CXX="$CXX $switch"
+         AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])],
+          [eval $cachevar=yes],
+          [eval $cachevar=no])
+         CXX="$ac_save_CXX"])
+      if eval test x\$$cachevar = xyes; then
+        CXX="$CXX $switch"
+        if test -n "$CXXCPP" ; then
+          CXXCPP="$CXXCPP $switch"
+        fi
+        ac_success=yes
+        break
+      fi
+    done
+  fi])
+
+  m4_if([$2], [ext], [], [dnl
+  if test x$ac_success = xno; then
+    dnl HP's aCC needs +std=c++11 according to:
+    dnl http://h21007.www2.hp.com/portal/download/files/unprot/aCxx/PDF_Release_Notes/769149-001.pdf
+    dnl Cray's crayCC needs "-h std=c++11"
+    for alternative in ${ax_cxx_compile_alternatives}; do
+      for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do
+        cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch])
+        AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch,
+                       $cachevar,
+          [ac_save_CXX="$CXX"
+           CXX="$CXX $switch"
+           AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])],
+            [eval $cachevar=yes],
+            [eval $cachevar=no])
+           CXX="$ac_save_CXX"])
+        if eval test x\$$cachevar = xyes; then
+          CXX="$CXX $switch"
+          if test -n "$CXXCPP" ; then
+            CXXCPP="$CXXCPP $switch"
+          fi
+          ac_success=yes
+          break
+        fi
+      done
+      if test x$ac_success = xyes; then
+        break
+      fi
+    done
+  fi])
+  AC_LANG_POP([C++])
+  if test x$ax_cxx_compile_cxx$1_required = xtrue; then
+    if test x$ac_success = xno; then
+      AC_MSG_ERROR([*** A compiler with support for C++$1 language features is required.])
+    fi
+  fi
+  if test x$ac_success = xno; then
+    HAVE_CXX$1=0
+    AC_MSG_NOTICE([No compiler with C++$1 support was found])
+  else
+    HAVE_CXX$1=1
+    AC_DEFINE(HAVE_CXX$1,1,
+              [define if the compiler supports basic C++$1 syntax])
+  fi
+  AC_SUBST(HAVE_CXX$1)
+  m4_if([$1], [17], [AC_MSG_WARN([C++17 is not yet standardized, so the checks may change in incompatible ways anytime])])
+])
+
+
+dnl  Test body for checking C++11 support
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_11],
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_11
+)
+
+
+dnl  Test body for checking C++14 support
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14],
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_11
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_14
+)
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_17],
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_11
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_14
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_17
+)
+
+dnl  Tests for new features in C++11
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[
+
+// If the compiler admits that it is not ready for C++11, why torture it?
+// Hopefully, this will speed up the test.
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus < 201103L
+
+#error "This is not a C++11 compiler"
+
+#else
+
+namespace cxx11
+{
+
+  namespace test_static_assert
+  {
+
+    template <typename T>
+    struct check
+    {
+      static_assert(sizeof(int) <= sizeof(T), "not big enough");
+    };
+
+  }
+
+  namespace test_final_override
+  {
+
+    struct Base
+    {
+      virtual void f() {}
+    };
+
+    struct Derived : public Base
+    {
+      virtual void f() override {}
+    };
+
+  }
+
+  namespace test_double_right_angle_brackets
+  {
+
+    template < typename T >
+    struct check {};
+
+    typedef check<void> single_type;
+    typedef check<check<void>> double_type;
+    typedef check<check<check<void>>> triple_type;
+    typedef check<check<check<check<void>>>> quadruple_type;
+
+  }
+
+  namespace test_decltype
+  {
+
+    int
+    f()
+    {
+      int a = 1;
+      decltype(a) b = 2;
+      return a + b;
+    }
+
+  }
+
+  namespace test_type_deduction
+  {
+
+    template < typename T1, typename T2 >
+    struct is_same
+    {
+      static const bool value = false;
+    };
+
+    template < typename T >
+    struct is_same<T, T>
+    {
+      static const bool value = true;
+    };
+
+    template < typename T1, typename T2 >
+    auto
+    add(T1 a1, T2 a2) -> decltype(a1 + a2)
+    {
+      return a1 + a2;
+    }
+
+    int
+    test(const int c, volatile int v)
+    {
+      static_assert(is_same<int, decltype(0)>::value == true, "");
+      static_assert(is_same<int, decltype(c)>::value == false, "");
+      static_assert(is_same<int, decltype(v)>::value == false, "");
+      auto ac = c;
+      auto av = v;
+      auto sumi = ac + av + 'x';
+      auto sumf = ac + av + 1.0;
+      static_assert(is_same<int, decltype(ac)>::value == true, "");
+      static_assert(is_same<int, decltype(av)>::value == true, "");
+      static_assert(is_same<int, decltype(sumi)>::value == true, "");
+      static_assert(is_same<int, decltype(sumf)>::value == false, "");
+      static_assert(is_same<int, decltype(add(c, v))>::value == true, "");
+      return (sumf > 0.0) ? sumi : add(c, v);
+    }
+
+  }
+
+  namespace test_noexcept
+  {
+
+    int f() { return 0; }
+    int g() noexcept { return 0; }
+
+    static_assert(noexcept(f()) == false, "");
+    static_assert(noexcept(g()) == true, "");
+
+  }
+
+  namespace test_constexpr
+  {
+
+    template < typename CharT >
+    unsigned long constexpr
+    strlen_c_r(const CharT *const s, const unsigned long acc) noexcept
+    {
+      return *s ? strlen_c_r(s + 1, acc + 1) : acc;
+    }
+
+    template < typename CharT >
+    unsigned long constexpr
+    strlen_c(const CharT *const s) noexcept
+    {
+      return strlen_c_r(s, 0UL);
+    }
+
+    static_assert(strlen_c("") == 0UL, "");
+    static_assert(strlen_c("1") == 1UL, "");
+    static_assert(strlen_c("example") == 7UL, "");
+    static_assert(strlen_c("another\0example") == 7UL, "");
+
+  }
+
+  namespace test_rvalue_references
+  {
+
+    template < int N >
+    struct answer
+    {
+      static constexpr int value = N;
+    };
+
+    answer<1> f(int&)       { return answer<1>(); }
+    answer<2> f(const int&) { return answer<2>(); }
+    answer<3> f(int&&)      { return answer<3>(); }
+
+    void
+    test()
+    {
+      int i = 0;
+      const int c = 0;
+      static_assert(decltype(f(i))::value == 1, "");
+      static_assert(decltype(f(c))::value == 2, "");
+      static_assert(decltype(f(0))::value == 3, "");
+    }
+
+  }
+
+  namespace test_uniform_initialization
+  {
+
+    struct test
+    {
+      static const int zero {};
+      static const int one {1};
+    };
+
+    static_assert(test::zero == 0, "");
+    static_assert(test::one == 1, "");
+
+  }
+
+  namespace test_lambdas
+  {
+
+    void
+    test1()
+    {
+      auto lambda1 = [](){};
+      auto lambda2 = lambda1;
+      lambda1();
+      lambda2();
+    }
+
+    int
+    test2()
+    {
+      auto a = [](int i, int j){ return i + j; }(1, 2);
+      auto b = []() -> int { return '0'; }();
+      auto c = [=](){ return a + b; }();
+      auto d = [&](){ return c; }();
+      auto e = [a, &b](int x) mutable {
+        const auto identity = [](int y){ return y; };
+        for (auto i = 0; i < a; ++i)
+          a += b--;
+        return x + identity(a + b);
+      }(0);
+      return a + b + c + d + e;
+    }
+
+    int
+    test3()
+    {
+      const auto nullary = [](){ return 0; };
+      const auto unary = [](int x){ return x; };
+      using nullary_t = decltype(nullary);
+      using unary_t = decltype(unary);
+      const auto higher1st = [](nullary_t f){ return f(); };
+      const auto higher2nd = [unary](nullary_t f1){
+        return [unary, f1](unary_t f2){ return f2(unary(f1())); };
+      };
+      return higher1st(nullary) + higher2nd(nullary)(unary);
+    }
+
+  }
+
+  namespace test_variadic_templates
+  {
+
+    template <int...>
+    struct sum;
+
+    template <int N0, int... N1toN>
+    struct sum<N0, N1toN...>
+    {
+      static constexpr auto value = N0 + sum<N1toN...>::value;
+    };
+
+    template <>
+    struct sum<>
+    {
+      static constexpr auto value = 0;
+    };
+
+    static_assert(sum<>::value == 0, "");
+    static_assert(sum<1>::value == 1, "");
+    static_assert(sum<23>::value == 23, "");
+    static_assert(sum<1, 2>::value == 3, "");
+    static_assert(sum<5, 5, 11>::value == 21, "");
+    static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, "");
+
+  }
+
+  // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae
+  // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function
+  // because of this.
+  namespace test_template_alias_sfinae
+  {
+
+    struct foo {};
+
+    template<typename T>
+    using member = typename T::member_type;
+
+    template<typename T>
+    void func(...) {}
+
+    template<typename T>
+    void func(member<T>*) {}
+
+    void test();
+
+    void test() { func<foo>(0); }
+
+  }
+
+}  // namespace cxx11
+
+#endif  // __cplusplus >= 201103L
+
+]])
+
+
+dnl  Tests for new features in C++14
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_14], [[
+
+// If the compiler admits that it is not ready for C++14, why torture it?
+// Hopefully, this will speed up the test.
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus < 201402L
+
+#error "This is not a C++14 compiler"
+
+#else
+
+namespace cxx14
+{
+
+  namespace test_polymorphic_lambdas
+  {
+
+    int
+    test()
+    {
+      const auto lambda = [](auto&&... args){
+        const auto istiny = [](auto x){
+          return (sizeof(x) == 1UL) ? 1 : 0;
+        };
+        const int aretiny[] = { istiny(args)... };
+        return aretiny[0];
+      };
+      return lambda(1, 1L, 1.0f, '1');
+    }
+
+  }
+
+  namespace test_binary_literals
+  {
+
+    constexpr auto ivii = 0b0000000000101010;
+    static_assert(ivii == 42, "wrong value");
+
+  }
+
+  namespace test_generalized_constexpr
+  {
+
+    template < typename CharT >
+    constexpr unsigned long
+    strlen_c(const CharT *const s) noexcept
+    {
+      auto length = 0UL;
+      for (auto p = s; *p; ++p)
+        ++length;
+      return length;
+    }
+
+    static_assert(strlen_c("") == 0UL, "");
+    static_assert(strlen_c("x") == 1UL, "");
+    static_assert(strlen_c("test") == 4UL, "");
+    static_assert(strlen_c("another\0test") == 7UL, "");
+
+  }
+
+  namespace test_lambda_init_capture
+  {
+
+    int
+    test()
+    {
+      auto x = 0;
+      const auto lambda1 = [a = x](int b){ return a + b; };
+      const auto lambda2 = [a = lambda1(x)](){ return a; };
+      return lambda2();
+    }
+
+  }
+
+  namespace test_digit_separators
+  {
+
+    constexpr auto ten_million = 100'000'000;
+    static_assert(ten_million == 100000000, "");
+
+  }
+
+  namespace test_return_type_deduction
+  {
+
+    auto f(int& x) { return x; }
+    decltype(auto) g(int& x) { return x; }
+
+    template < typename T1, typename T2 >
+    struct is_same
+    {
+      static constexpr auto value = false;
+    };
+
+    template < typename T >
+    struct is_same<T, T>
+    {
+      static constexpr auto value = true;
+    };
+
+    int
+    test()
+    {
+      auto x = 0;
+      static_assert(is_same<int, decltype(f(x))>::value, "");
+      static_assert(is_same<int&, decltype(g(x))>::value, "");
+      return x;
+    }
+
+  }
+
+}  // namespace cxx14
+
+#endif  // __cplusplus >= 201402L
+
+]])
+
+
+dnl  Tests for new features in C++17
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[
+
+// If the compiler admits that it is not ready for C++17, why torture it?
+// Hopefully, this will speed up the test.
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus <= 201402L
+
+#error "This is not a C++17 compiler"
+
+#else
+
+#if defined(__clang__)
+  #define REALLY_CLANG
+#else
+  #if defined(__GNUC__)
+    #define REALLY_GCC
+  #endif
+#endif
+
+#include <initializer_list>
+#include <utility>
+#include <type_traits>
+
+namespace cxx17
+{
+
+#if !defined(REALLY_CLANG)
+  namespace test_constexpr_lambdas
+  {
+
+    // TODO: test it with clang++ from git
+
+    constexpr int foo = [](){return 42;}();
+
+  }
+#endif // !defined(REALLY_CLANG)
+
+  namespace test::nested_namespace::definitions
+  {
+
+  }
+
+  namespace test_fold_expression
+  {
+
+    template<typename... Args>
+    int multiply(Args... args)
+    {
+      return (args * ... * 1);
+    }
+
+    template<typename... Args>
+    bool all(Args... args)
+    {
+      return (args && ...);
+    }
+
+  }
+
+  namespace test_extended_static_assert
+  {
+
+    static_assert (true);
+
+  }
+
+  namespace test_auto_brace_init_list
+  {
+
+    auto foo = {5};
+    auto bar {5};
+
+    static_assert(std::is_same<std::initializer_list<int>, decltype(foo)>::value);
+    static_assert(std::is_same<int, decltype(bar)>::value);
+  }
+
+  namespace test_typename_in_template_template_parameter
+  {
+
+    template<template<typename> typename X> struct D;
+
+  }
+
+  namespace test_fallthrough_nodiscard_maybe_unused_attributes
+  {
+
+    int f1()
+    {
+      return 42;
+    }
+
+    [[nodiscard]] int f2()
+    {
+      [[maybe_unused]] auto unused = f1();
+
+      switch (f1())
+      {
+      case 17:
+        f1();
+        [[fallthrough]];
+      case 42:
+        f1();
+      }
+      return f1();
+    }
+
+  }
+
+  namespace test_extended_aggregate_initialization
+  {
+
+    struct base1
+    {
+      int b1, b2 = 42;
+    };
+
+    struct base2
+    {
+      base2() {
+        b3 = 42;
+      }
+      int b3;
+    };
+
+    struct derived : base1, base2
+    {
+        int d;
+    };
+
+    derived d1 {{1, 2}, {}, 4};  // full initialization
+    derived d2 {{}, {}, 4};      // value-initialized bases
+
+  }
+
+  namespace test_general_range_based_for_loop
+  {
+
+    struct iter
+    {
+      int i;
+
+      int& operator* ()
+      {
+        return i;
+      }
+
+      const int& operator* () const
+      {
+        return i;
+      }
+
+      iter& operator++()
+      {
+        ++i;
+        return *this;
+      }
+    };
+
+    struct sentinel
+    {
+      int i;
+    };
+
+    bool operator== (const iter& i, const sentinel& s)
+    {
+      return i.i == s.i;
+    }
+
+    bool operator!= (const iter& i, const sentinel& s)
+    {
+      return !(i == s);
+    }
+
+    struct range
+    {
+      iter begin() const
+      {
+        return {0};
+      }
+
+      sentinel end() const
+      {
+        return {5};
+      }
+    };
+
+    void f()
+    {
+      range r {};
+
+      for (auto i : r)
+      {
+        [[maybe_unused]] auto v = i;
+      }
+    }
+
+  }
+
+  namespace test_lambda_capture_asterisk_this_by_value
+  {
+
+    struct t
+    {
+      int i;
+      int foo()
+      {
+        return [*this]()
+        {
+          return i;
+        }();
+      }
+    };
+
+  }
+
+  namespace test_enum_class_construction
+  {
+
+    enum class byte : unsigned char
+    {};
+
+    byte foo {42};
+
+  }
+
+  namespace test_constexpr_if
+  {
+
+    template <bool cond>
+    int f ()
+    {
+      if constexpr(cond)
+      {
+        return 13;
+      }
+      else
+      {
+        return 42;
+      }
+    }
+
+  }
+
+  namespace test_selection_statement_with_initializer
+  {
+
+    int f()
+    {
+      return 13;
+    }
+
+    int f2()
+    {
+      if (auto i = f(); i > 0)
+      {
+        return 3;
+      }
+
+      switch (auto i = f(); i + 4)
+      {
+      case 17:
+        return 2;
+
+      default:
+        return 1;
+      }
+    }
+
+  }
+
+#if !defined(REALLY_CLANG)
+  namespace test_template_argument_deduction_for_class_templates
+  {
+
+    // TODO: test it with clang++ from git
+
+    template <typename T1, typename T2>
+    struct pair
+    {
+      pair (T1 p1, T2 p2)
+        : m1 {p1},
+          m2 {p2}
+      {}
+
+      T1 m1;
+      T2 m2;
+    };
+
+    void f()
+    {
+      [[maybe_unused]] auto p = pair{13, 42u};
+    }
+
+  }
+#endif // !defined(REALLY_CLANG)
+
+  namespace test_non_type_auto_template_parameters
+  {
+
+    template <auto n>
+    struct B
+    {};
+
+    B<5> b1;
+    B<'a'> b2;
+
+  }
+
+#if !defined(REALLY_CLANG)
+  namespace test_structured_bindings
+  {
+
+    // TODO: test it with clang++ from git
+
+    int arr[2] = { 1, 2 };
+    std::pair<int, int> pr = { 1, 2 };
+
+    auto f1() -> int(&)[2]
+    {
+      return arr;
+    }
+
+    auto f2() -> std::pair<int, int>&
+    {
+      return pr;
+    }
+
+    struct S
+    {
+      int x1 : 2;
+      volatile double y1;
+    };
+
+    S f3()
+    {
+      return {};
+    }
+
+    auto [ x1, y1 ] = f1();
+    auto& [ xr1, yr1 ] = f1();
+    auto [ x2, y2 ] = f2();
+    auto& [ xr2, yr2 ] = f2();
+    const auto [ x3, y3 ] = f3();
+
+  }
+#endif // !defined(REALLY_CLANG)
+
+#if !defined(REALLY_CLANG)
+  namespace test_exception_spec_type_system
+  {
+
+    // TODO: test it with clang++ from git
+
+    struct Good {};
+    struct Bad {};
+
+    void g1() noexcept;
+    void g2();
+
+    template<typename T>
+    Bad
+    f(T*, T*);
+
+    template<typename T1, typename T2>
+    Good
+    f(T1*, T2*);
+
+    static_assert (std::is_same_v<Good, decltype(f(g1, g2))>);
+
+  }
+#endif // !defined(REALLY_CLANG)
+
+  namespace test_inline_variables
+  {
+
+    template<class T> void f(T)
+    {}
+
+    template<class T> inline T g(T)
+    {
+      return T{};
+    }
+
+    template<> inline void f<>(int)
+    {}
+
+    template<> int g<>(int)
+    {
+      return 5;
+    }
+
+  }
+
+}  // namespace cxx17
+
+#endif  // __cplusplus <= 201402L
+
+]])
diff --git a/aclocal/ax_cxx_compile_stdcxx_11.m4 b/aclocal/ax_cxx_compile_stdcxx_11.m4
index a9a8f58..1733fd8 100644
--- a/aclocal/ax_cxx_compile_stdcxx_11.m4
+++ b/aclocal/ax_cxx_compile_stdcxx_11.m4
@@ -1,26 +1,23 @@
-# ============================================================================
-#  http://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_11.html
-# ============================================================================
+# =============================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_11.html
+# =============================================================================
 #
 # SYNOPSIS
 #
-#   AX_CXX_COMPILE_STDCXX_11([ext|noext],[mandatory|optional])
+#   AX_CXX_COMPILE_STDCXX_11([ext|noext], [mandatory|optional])
 #
 # DESCRIPTION
 #
 #   Check for baseline language coverage in the compiler for the C++11
-#   standard; if necessary, add switches to CXXFLAGS to enable support.
+#   standard; if necessary, add switches to CXX and CXXCPP to enable
+#   support.
 #
-#   The first argument, if specified, indicates whether you insist on an
-#   extended mode (e.g. -std=gnu++11) or a strict conformance mode (e.g.
-#   -std=c++11).  If neither is specified, you get whatever works, with
-#   preference for an extended mode.
-#
-#   The second argument, if specified 'mandatory' or if left unspecified,
-#   indicates that baseline C++11 support is required and that the macro
-#   should error out if no mode with that support is found.  If specified
-#   'optional', then configuration proceeds regardless, after defining
-#   HAVE_CXX11 if and only if a supporting mode is found.
+#   This macro is a convenience alias for calling the AX_CXX_COMPILE_STDCXX
+#   macro with the version set to C++11.  The two optional arguments are
+#   forwarded literally as the second and third argument respectively.
+#   Please see the documentation for the AX_CXX_COMPILE_STDCXX macro for
+#   more information.  If you want to use this macro, you also need to
+#   download the ax_cxx_compile_stdcxx.m4 file.
 #
 # LICENSE
 #
@@ -28,138 +25,15 @@
 #   Copyright (c) 2012 Zack Weinberg <zackw@panix.com>
 #   Copyright (c) 2013 Roy Stogner <roystgnr@ices.utexas.edu>
 #   Copyright (c) 2014, 2015 Google Inc.; contributed by Alexey Sokolov <sokolov@google.com>
+#   Copyright (c) 2015 Paul Norman <penorman@mac.com>
+#   Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu>
 #
 #   Copying and distribution of this file, with or without modification, are
 #   permitted in any medium without royalty provided the copyright notice
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 10
+#serial 18
 
-m4_define([_AX_CXX_COMPILE_STDCXX_11_testbody], [[
-  template <typename T>
-    struct check
-    {
-      static_assert(sizeof(int) <= sizeof(T), "not big enough");
-    };
-
-    struct Base {
-    virtual void f() {}
-    };
-    struct Child : public Base {
-    virtual void f() override {}
-    };
-
-    typedef check<check<bool>> right_angle_brackets;
-
-    int a;
-    decltype(a) b;
-
-    typedef check<int> check_type;
-    check_type c;
-    check_type&& cr = static_cast<check_type&&>(c);
-
-    auto d = a;
-    auto l = [](){};
-    // Prevent Clang error: unused variable 'l' [-Werror,-Wunused-variable]
-    struct use_l { use_l() { l(); } };
-
-    // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae
-    // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function because of this
-    namespace test_template_alias_sfinae {
-        struct foo {};
-
-        template<typename T>
-        using member = typename T::member_type;
-
-        template<typename T>
-        void func(...) {}
-
-        template<typename T>
-        void func(member<T>*) {}
-
-        void test();
-
-        void test() {
-            func<foo>(0);
-        }
-    }
-]])
-
-AC_DEFUN([AX_CXX_COMPILE_STDCXX_11], [dnl
-  m4_if([$1], [], [],
-        [$1], [ext], [],
-        [$1], [noext], [],
-        [m4_fatal([invalid argument `$1' to AX_CXX_COMPILE_STDCXX_11])])dnl
-  m4_if([$2], [], [ax_cxx_compile_cxx11_required=true],
-        [$2], [mandatory], [ax_cxx_compile_cxx11_required=true],
-        [$2], [optional], [ax_cxx_compile_cxx11_required=false],
-        [m4_fatal([invalid second argument `$2' to AX_CXX_COMPILE_STDCXX_11])])
-  AC_LANG_PUSH([C++])dnl
-  ac_success=no
-  AC_CACHE_CHECK(whether $CXX supports C++11 features by default,
-  ax_cv_cxx_compile_cxx11,
-  [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_11_testbody])],
-    [ax_cv_cxx_compile_cxx11=yes],
-    [ax_cv_cxx_compile_cxx11=no])])
-  if test x$ax_cv_cxx_compile_cxx11 = xyes; then
-    ac_success=yes
-  fi
-
-  m4_if([$1], [noext], [], [dnl
-  if test x$ac_success = xno; then
-    for switch in -std=gnu++11 -std=gnu++0x; do
-      cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx11_$switch])
-      AC_CACHE_CHECK(whether $CXX supports C++11 features with $switch,
-                     $cachevar,
-        [ac_save_CXXFLAGS="$CXXFLAGS"
-         CXXFLAGS="$CXXFLAGS $switch"
-         AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_11_testbody])],
-          [eval $cachevar=yes],
-          [eval $cachevar=no])
-         CXXFLAGS="$ac_save_CXXFLAGS"])
-      if eval test x\$$cachevar = xyes; then
-        CXXFLAGS="$CXXFLAGS $switch"
-        ac_success=yes
-        break
-      fi
-    done
-  fi])
-
-  m4_if([$1], [ext], [], [dnl
-  if test x$ac_success = xno; then
-    for switch in -std=c++11 -std=c++0x; do
-      cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx11_$switch])
-      AC_CACHE_CHECK(whether $CXX supports C++11 features with $switch,
-                     $cachevar,
-        [ac_save_CXXFLAGS="$CXXFLAGS"
-         CXXFLAGS="$CXXFLAGS $switch"
-         AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_11_testbody])],
-          [eval $cachevar=yes],
-          [eval $cachevar=no])
-         CXXFLAGS="$ac_save_CXXFLAGS"])
-      if eval test x\$$cachevar = xyes; then
-        CXXFLAGS="$CXXFLAGS $switch"
-        ac_success=yes
-        break
-      fi
-    done
-  fi])
-  AC_LANG_POP([C++])
-  if test x$ax_cxx_compile_cxx11_required = xtrue; then
-    if test x$ac_success = xno; then
-      AC_MSG_ERROR([*** A compiler with support for C++11 language features is required.])
-    fi
-  else
-    if test x$ac_success = xno; then
-      HAVE_CXX11=0
-      AC_MSG_NOTICE([No compiler with C++11 support was found])
-    else
-      HAVE_CXX11=1
-      AC_DEFINE(HAVE_CXX11,1,
-                [define if the compiler supports basic C++11 syntax])
-    fi
-
-    AC_SUBST(HAVE_CXX11)
-  fi
-])
+AX_REQUIRE_DEFINED([AX_CXX_COMPILE_STDCXX])
+AC_DEFUN([AX_CXX_COMPILE_STDCXX_11], [AX_CXX_COMPILE_STDCXX([11], [$1], [$2])])