diff --git a/.gitignore b/.gitignore
index f92e478..58b65e8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -57,3 +57,5 @@ examples/example23
 examples/example24
 examples/example25
 
+
+*.exe
\ No newline at end of file
diff --git a/Makefile.am b/Makefile.am
index 4743d60..f20af0e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,9 +1,9 @@
-ACLOCAL_AMFLAGS = -I m4
-SUBDIRS = src include examples doc 
-EXTRA_DIST = curlpp.VC8.vcproj curlpp.VC8.sln CHANGES curlpp.spec README.win32 win32/*
-
-pkgconfigdir = $(libdir)/pkgconfig
-pkgconfig_DATA = curlpp.pc
-
-bin_SCRIPTS = curlpp-config
-
+ACLOCAL_AMFLAGS = ${ACLOCAL_FLAGS} -I m4
+SUBDIRS = src include examples doc 
+EXTRA_DIST = curlpp.VC8.vcproj curlpp.VC8.sln CHANGES curlpp.spec README.win32 win32/*
+
+pkgconfigdir = $(libdir)/pkgconfig
+pkgconfig_DATA = curlpp.pc
+
+bin_SCRIPTS = curlpp-config
+
diff --git a/examples/Makefile.am b/examples/Makefile.am
index 9004291..692b626 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -1,91 +1,95 @@
-if MAINTENER_CODE
-maintener_programs = 
-endif
-
-if HAVE_BOOST
-boost_programs = example18 example20
-endif
-
-EXTRA_DIST = Makefile.msvc
-
-noinst_PROGRAMS = \
-	example01 \
-	example02 \
-	example03 \
-	example04 \
-	example05 \
-	example06 \
-	example07 \
-	example08 \
-	example09 \
-	example10 \
-	example11 \
-	example12 \
-	example13 \
-	example14 \
-	example15 \
-	example16 \
-	example17 \
-	example19 \
-	example21 \
-	example22 \
-	example23 \
-	example24 \
-	${maintener_programs} ${boost_programs}
-
-
-
-example01_SOURCES = example01.cpp
-
-example02_SOURCES = example02.cpp
-
-example03_SOURCES = example03.cpp
-
-example04_SOURCES = example04.cpp
-
-example05_SOURCES = example05.cpp
-
-example06_SOURCES = example06.cpp
-
-example07_SOURCES = example07.cpp
-
-example08_SOURCES = example08.cpp
-
-example09_SOURCES = example09.cpp
-
-example10_SOURCES = example10.cpp
-
-example11_SOURCES = example11.cpp
-
-example12_SOURCES = example12.cpp
-
-example13_SOURCES = example13.cpp
-
-example14_SOURCES = example14.cpp
-
-example15_SOURCES = example15.cpp
-
-example16_SOURCES = example16.cpp
-
-example17_SOURCES = example17.cpp
-
-example18_SOURCES = example18.cpp
-
-example19_SOURCES = example19.cpp
-
-example20_SOURCES = example20.cpp
-
-example21_SOURCES = example21.cpp
-
-example22_SOURCES = example22.cpp
-
-example23_SOURCES = example23.cpp
-
-example24_SOURCES = example24.cpp
-
-AM_LDFLAGS = -L../src/curlpp/ -lcurlpp -static 
-
-AM_CPPFLAGS = -I$(top_builddir)/include
-
-
-
+if MAINTENER_CODE
+maintener_programs = 
+endif
+
+if HAVE_BOOST
+boost_programs = example18 example20
+endif
+
+EXTRA_DIST = Makefile.msvc
+
+noinst_PROGRAMS = \
+	example01 \
+	example02 \
+	example03 \
+	example04 \
+	example05 \
+	example06 \
+	example07 \
+	example08 \
+	example09 \
+	example10 \
+	example11 \
+	example12 \
+	example13 \
+	example14 \
+	example15 \
+	example16 \
+	example17 \
+	example19 \
+	example21 \
+	example22 \
+	example23 \
+	example24 \
+	${maintener_programs} ${boost_programs}
+
+
+
+example01_SOURCES = example01.cpp
+
+example02_SOURCES = example02.cpp
+
+example03_SOURCES = example03.cpp
+
+example04_SOURCES = example04.cpp
+
+example05_SOURCES = example05.cpp
+
+example06_SOURCES = example06.cpp
+
+example07_SOURCES = example07.cpp
+
+example08_SOURCES = example08.cpp
+
+example09_SOURCES = example09.cpp
+
+example10_SOURCES = example10.cpp
+
+example11_SOURCES = example11.cpp
+
+example12_SOURCES = example12.cpp
+
+example13_SOURCES = example13.cpp
+
+example14_SOURCES = example14.cpp
+
+example15_SOURCES = example15.cpp
+
+example16_SOURCES = example16.cpp
+
+example17_SOURCES = example17.cpp
+
+if HAVE_BOOST
+example18_SOURCES = example18.cpp
+endif
+
+example19_SOURCES = example19.cpp
+
+if HAVE_BOOST
+example20_SOURCES = example20.cpp
+endif
+
+example21_SOURCES = example21.cpp
+
+example22_SOURCES = example22.cpp
+
+example23_SOURCES = example23.cpp
+
+example24_SOURCES = example24.cpp
+
+AM_LDFLAGS = -L../src/curlpp/ -lcurlpp -static 
+
+AM_CPPFLAGS = -I$(top_builddir)/include
+
+
+
diff --git a/examples/example18.cpp b/examples/example18.cpp
index 12c9ea3..ba7d847 100644
--- a/examples/example18.cpp
+++ b/examples/example18.cpp
@@ -31,7 +31,9 @@
 #include <sstream>
 #include <cstdlib>
 
+#ifdef HAVE_BOOST
 #include <boost/bind.hpp>
+#endif
 #include <curlpp/cURLpp.hpp>
 #include <curlpp/Easy.hpp>
 #include <curlpp/Options.hpp>
diff --git a/examples/example20.cpp b/examples/example20.cpp
index ac3b28d..8e6ae27 100644
--- a/examples/example20.cpp
+++ b/examples/example20.cpp
@@ -1,75 +1,74 @@
-/*
- *    Copyright (c) <2002-2005> <Jean-Philippe Barrette-LaPierre>
- *    
- *    Permission is hereby granted, free of charge, to any person obtaining
- *    a copy of this software and associated documentation files 
- *    (curlpp), to deal in the Software without restriction, 
- *    including without limitation the rights to use, copy, modify, merge,
- *    publish, distribute, sublicense, and/or sell copies of the Software,
- *    and to permit persons to whom the Software is furnished to do so, 
- *    subject to the following conditions:
- *    
- *    The above copyright notice and this permission notice shall be included
- *    in all copies or substantial portions of the Software.
- *    
- *    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- *    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- *    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
- *    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY 
- *    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
- *    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
- *    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-/**
-* \file
-* Using WriteStream option.
-* 
-*/
-
-
-#include <sstream>
-
-#include <cstdlib>
-
-#include <boost/bind.hpp>
-#include <curlpp/cURLpp.hpp>
-#include <curlpp/Easy.hpp>
-#include <curlpp/Options.hpp>
-#include <curlpp/Exception.hpp>
-
-int main(int argc, char *argv[])
-{
-  if(argc != 2) {
-    std::cerr << argv[0] << ": Wrong number of arguments" << std::endl 
-	      << argv[0] << ": Usage: " << " url " 
-	      << std::endl;
-    return EXIT_FAILURE;
-  }
-
-  char *url = argv[1];
-  
-  try {
-    curlpp::Cleanup cleaner;
-    curlpp::Easy request;
-
-    // Set the writer callback to enable cURL 
-    // to write result in a memory area
-    request.setOpt(new curlpp::options::WriteStream(&std::cout));
-    
-    // Setting the URL to retrive.
-    request.setOpt(new curlpp::options::Url(url));
-
-    request.perform();
-
-    return EXIT_SUCCESS;
-  }
-  catch ( curlpp::LogicError & e ) {
-    std::cout << e.what() << std::endl;
-  }
-  catch ( curlpp::RuntimeError & e ) {
-    std::cout << e.what() << std::endl;
-  }
-
-  return EXIT_FAILURE;
-}
+/*
+ *    Copyright (c) <2002-2005> <Jean-Philippe Barrette-LaPierre>
+ *    
+ *    Permission is hereby granted, free of charge, to any person obtaining
+ *    a copy of this software and associated documentation files 
+ *    (curlpp), to deal in the Software without restriction, 
+ *    including without limitation the rights to use, copy, modify, merge,
+ *    publish, distribute, sublicense, and/or sell copies of the Software,
+ *    and to permit persons to whom the Software is furnished to do so, 
+ *    subject to the following conditions:
+ *    
+ *    The above copyright notice and this permission notice shall be included
+ *    in all copies or substantial portions of the Software.
+ *    
+ *    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ *    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
+ *    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY 
+ *    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
+ *    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ *    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+* \file
+* Using WriteStream option.
+* 
+*/
+
+
+#include <sstream>
+
+#include <cstdlib>
+
+#include <curlpp/cURLpp.hpp>
+#include <curlpp/Easy.hpp>
+#include <curlpp/Options.hpp>
+#include <curlpp/Exception.hpp>
+
+int main(int argc, char *argv[])
+{
+  if(argc != 2) {
+    std::cerr << argv[0] << ": Wrong number of arguments" << std::endl 
+	      << argv[0] << ": Usage: " << " url " 
+	      << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  char *url = argv[1];
+  
+  try {
+    curlpp::Cleanup cleaner;
+    curlpp::Easy request;
+
+    // Set the writer callback to enable cURL 
+    // to write result in a memory area
+    request.setOpt(new curlpp::options::WriteStream(&std::cout));
+    
+    // Setting the URL to retrive.
+    request.setOpt(new curlpp::options::Url(url));
+
+    request.perform();
+
+    return EXIT_SUCCESS;
+  }
+  catch ( curlpp::LogicError & e ) {
+    std::cout << e.what() << std::endl;
+  }
+  catch ( curlpp::RuntimeError & e ) {
+    std::cout << e.what() << std::endl;
+  }
+
+  return EXIT_FAILURE;
+}
diff --git a/m4/ax_boost_base.m4 b/m4/ax_boost_base.m4
index 2e5afd0..ab46745 100644
--- a/m4/ax_boost_base.m4
+++ b/m4/ax_boost_base.m4
@@ -1,10 +1,10 @@
 # ===========================================================================
-#             http://autoconf-archive.cryp.to/ax_boost_base.html
+#       http://www.gnu.org/software/autoconf-archive/ax_boost_base.html
 # ===========================================================================
 #
 # SYNOPSIS
 #
-#   AX_BOOST_BASE([MINIMUM-VERSION])
+#   AX_BOOST_BASE([MINIMUM-VERSION], [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
 #
 # DESCRIPTION
 #
@@ -23,41 +23,45 @@
 #
 #     HAVE_BOOST
 #
-# LAST MODIFICATION
-#
-#   2008-04-12
-#
-# COPYLEFT
+# LICENSE
 #
 #   Copyright (c) 2008 Thomas Porschberg <thomas@randspringer.de>
+#   Copyright (c) 2009 Peter Adolphs
 #
 #   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.
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 27
 
 AC_DEFUN([AX_BOOST_BASE],
 [
 AC_ARG_WITH([boost],
-	AS_HELP_STRING([--with-boost@<:@=DIR@:>@], [use boost (default is yes) - it is possible to specify the root directory for boost (optional)]),
-	[
+  [AS_HELP_STRING([--with-boost@<:@=ARG@:>@],
+    [use Boost library from a standard location (ARG=yes),
+     from the specified location (ARG=<path>),
+     or disable it (ARG=no)
+     @<:@ARG=yes@:>@ ])],
+    [
     if test "$withval" = "no"; then
-		want_boost="no"
+        want_boost="no"
     elif test "$withval" = "yes"; then
         want_boost="yes"
         ac_boost_path=""
     else
-	    want_boost="yes"
+        want_boost="yes"
         ac_boost_path="$withval"
-	fi
+    fi
     ],
     [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 overwrite library path detection, so use this parameter only if default library detection fails and you know exactly where your boost libraries are located.]),
+        [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 $withval
+        if test -d "$withval"
         then
                 ac_boost_lib_path="$withval"
         else
@@ -68,33 +72,69 @@ AC_ARG_WITH([boost-libdir],
 )
 
 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 >= $boost_lib_version_req)
-	succeeded=no
-
-	dnl first we check the system location for boost libraries
-	dnl this location ist chosen if boost libraries are installed with the --layout=system option
-	dnl or if you install boost with RPM
-	if test "$ac_boost_path" != ""; then
-		BOOST_LDFLAGS="-L$ac_boost_path/lib"
-		BOOST_CPPFLAGS="-I$ac_boost_path/include"
-	else
-		for ac_boost_path_tmp in /usr /usr/local /opt /opt/local ; do
-			if test -d "$ac_boost_path_tmp/include/boost" && test -r "$ac_boost_path_tmp/include/boost"; then
-				BOOST_LDFLAGS="-L$ac_boost_path_tmp/lib"
-				BOOST_CPPFLAGS="-I$ac_boost_path_tmp/include"
-				break;
-			fi
-		done
-	fi
+    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)
+    succeeded=no
+
+    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 $ax_arch in
+      x86_64)
+        libsubdirs="lib64 libx32 lib lib64"
+        ;;
+      ppc64|s390x|sparc64|aarch64|ppc64le)
+        libsubdirs="lib64 lib lib64"
+        ;;
+    esac
+
+    dnl allow for real multi-arch paths e.g. /usr/lib/x86_64-linux-gnu. Give
+    dnl them priority over the other paths since, if libs are found there, they
+    dnl are almost assuredly the ones desired.
+    AC_REQUIRE([AC_CANONICAL_HOST])
+    libsubdirs="lib/${host_cpu}-${host_os} $libsubdirs"
+
+    case ${host_cpu} in
+      i?86)
+        libsubdirs="lib/i386-${host_os} $libsubdirs"
+        ;;
+    esac
+
+    dnl first we check the system location for boost libraries
+    dnl this location ist chosen if boost libraries are installed with the --layout=system option
+    dnl or if you install boost with RPM
+    if test "$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 /usr /usr/local /opt /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/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
+                done
+                BOOST_LDFLAGS="-L$ac_boost_path_tmp/$libsubdir"
+                BOOST_CPPFLAGS="-I$ac_boost_path_tmp/include"
+                break;
+            fi
+        done
+    fi
 
     dnl overwrite ld flags if we have required special directory with
     dnl --with-boost-libdir parameter
@@ -102,122 +142,144 @@ if test "x$want_boost" = "xyes"; then
        BOOST_LDFLAGS="-L$ac_boost_lib_path"
     fi
 
-	CPPFLAGS_SAVED="$CPPFLAGS"
-	CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
-	export CPPFLAGS
-
-	LDFLAGS_SAVED="$LDFLAGS"
-	LDFLAGS="$LDFLAGS $BOOST_LDFLAGS"
-	export LDFLAGS
-
-	AC_LANG_PUSH(C++)
-     	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-	@%:@include <boost/version.hpp>
-	]], [[
-	#if BOOST_VERSION >= $WANT_BOOST_VERSION
-	// Everything is okay
-	#else
-	#  error Boost version is too old
-	#endif
-	]])],[
+    CPPFLAGS_SAVED="$CPPFLAGS"
+    CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
+    export CPPFLAGS
+
+    LDFLAGS_SAVED="$LDFLAGS"
+    LDFLAGS="$LDFLAGS $BOOST_LDFLAGS"
+    export LDFLAGS
+
+    AC_REQUIRE([AC_PROG_CXX])
+    AC_LANG_PUSH(C++)
+        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+    @%:@include <boost/version.hpp>
+    ]], [[
+    #if BOOST_VERSION >= $WANT_BOOST_VERSION
+    // Everything is okay
+    #else
+    #  error Boost version is too old
+    #endif
+    ]])],[
         AC_MSG_RESULT(yes)
-	succeeded=yes
-	found_system=yes
-       	],[
-       	])
-	AC_LANG_POP([C++])
-
-
-
-	dnl if we found no boost with system layout we search for boost libraries
-	dnl built and installed without the --layout=system option or for a staged(not installed) version
-	if test "x$succeeded" != "xyes"; then
-		_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/_/./'`
-					V_CHECK=`expr $_version_tmp \> $_version`
-					if test "$V_CHECK" = "1" ; then
-						_version=$_version_tmp
-					fi
-					VERSION_UNDERSCORE=`echo $_version | sed 's/\./_/'`
-					BOOST_CPPFLAGS="-I$ac_boost_path/include/boost-$VERSION_UNDERSCORE"
-				done
-			fi
-		else
-			for ac_boost_path in /usr /usr/local /opt /opt/local ; do
-				if test -d "$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/_/./'`
-						V_CHECK=`expr $_version_tmp \> $_version`
-						if test "$V_CHECK" = "1" ; then
-							_version=$_version_tmp
-	               					best_path=$ac_boost_path
-						fi
-					done
-				fi
-			done
-
-			VERSION_UNDERSCORE=`echo $_version | sed 's/\./_/'`
-			BOOST_CPPFLAGS="-I$best_path/include/boost-$VERSION_UNDERSCORE"
-            if test "$ac_boost_lib_path" = ""
-            then
-               BOOST_LDFLAGS="-L$best_path/lib"
+    succeeded=yes
+    found_system=yes
+        ],[
+        ])
+    AC_LANG_POP([C++])
+
+
+
+    dnl if we found no boost with system layout we search for boost libraries
+    dnl built and installed without the --layout=system option or for a staged(not installed) version
+    if test "x$succeeded" != "xyes"; then
+        CPPFLAGS="$CPPFLAGS_SAVED"
+        LDFLAGS="$LDFLAGS_SAVED"
+        BOOST_CPPFLAGS=
+        BOOST_LDFLAGS=
+        _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/_/./'`
+                    V_CHECK=`expr $_version_tmp \> $_version`
+                    if test "$V_CHECK" = "1" ; then
+                        _version=$_version_tmp
+                    fi
+                    VERSION_UNDERSCORE=`echo $_version | sed 's/\./_/'`
+                    BOOST_CPPFLAGS="-I$ac_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 "$ac_boost_path/boost" && test -r "$ac_boost_path/boost"; then
+                        BOOST_CPPFLAGS="-I$ac_boost_path"
+                    fi
+                fi
+            fi
+        else
+            if test "$cross_compiling" != yes; then
+                for ac_boost_path in /usr /usr/local /opt /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/_/./'`
+                            V_CHECK=`expr $_version_tmp \> $_version`
+                            if test "$V_CHECK" = "1" ; then
+                                _version=$_version_tmp
+                                best_path=$ac_boost_path
+                            fi
+                        done
+                    fi
+                done
+
+                VERSION_UNDERSCORE=`echo $_version | sed 's/\./_/'`
+                BOOST_CPPFLAGS="-I$best_path/include/boost-$VERSION_UNDERSCORE"
+                if test "$ac_boost_lib_path" = ""; then
+                    for libsubdir in $libsubdirs ; do
+                        if ls "$best_path/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
+                    done
+                    BOOST_LDFLAGS="-L$best_path/$libsubdir"
+                fi
             fi
 
-	    		if test "x$BOOST_ROOT" != "x"; then
-				if test -d "$BOOST_ROOT" && test -r "$BOOST_ROOT" && test -d "$BOOST_ROOT/stage/lib" && test -r "$BOOST_ROOT/stage/lib"; then
-					version_dir=`expr //$BOOST_ROOT : '.*/\(.*\)'`
-					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 \>\= $_version`
+            if test "x$BOOST_ROOT" != "x"; then
+                for libsubdir in $libsubdirs ; do
+                    if ls "$BOOST_ROOT/stage/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
+                done
+                if test -d "$BOOST_ROOT" && test -r "$BOOST_ROOT" && test -d "$BOOST_ROOT/stage/$libsubdir" && test -r "$BOOST_ROOT/stage/$libsubdir"; then
+                    version_dir=`expr //$BOOST_ROOT : '.*/\(.*\)'`
+                    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
-						AC_MSG_NOTICE(We will use a staged boost library from $BOOST_ROOT)
-						BOOST_CPPFLAGS="-I$BOOST_ROOT"
-						BOOST_LDFLAGS="-L$BOOST_ROOT/stage/lib"
-					fi
-				fi
-	    		fi
-		fi
-
-		CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
-		export CPPFLAGS
-		LDFLAGS="$LDFLAGS $BOOST_LDFLAGS"
-		export LDFLAGS
-
-		AC_LANG_PUSH(C++)
-	     	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-		@%:@include <boost/version.hpp>
-		]], [[
-		#if BOOST_VERSION >= $WANT_BOOST_VERSION
-		// Everything is okay
-		#else
-		#  error Boost version is too old
-		#endif
-		]])],[
-        	AC_MSG_RESULT(yes)
-		succeeded=yes
-		found_system=yes
-       		],[
-	       	])
-		AC_LANG_POP([C++])
-	fi
-
-	if test "$succeeded" != "yes" ; then
-		if test "$_version" = "0" ; then
-			AC_MSG_ERROR([[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.]])
-		else
-			AC_MSG_NOTICE([Your boost libraries seems to old (version $_version).])
-		fi
-	else
-		AC_SUBST(BOOST_CPPFLAGS)
-		AC_SUBST(BOOST_LDFLAGS)
-		AC_DEFINE(HAVE_BOOST,,[define if the Boost library is available])
-	fi
+                        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"
+                    fi
+                fi
+            fi
+        fi
 
-        CPPFLAGS="$CPPFLAGS_SAVED"
-       	LDFLAGS="$LDFLAGS_SAVED"
+        CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
+        export CPPFLAGS
+        LDFLAGS="$LDFLAGS $BOOST_LDFLAGS"
+        export LDFLAGS
+
+        AC_LANG_PUSH(C++)
+            AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+        @%:@include <boost/version.hpp>
+        ]], [[
+        #if BOOST_VERSION >= $WANT_BOOST_VERSION
+        // Everything is okay
+        #else
+        #  error Boost version is too old
+        #endif
+        ]])],[
+            AC_MSG_RESULT(yes)
+        succeeded=yes
+        found_system=yes
+            ],[
+            ])
+        AC_LANG_POP([C++])
+    fi
+
+    if test "$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.]])
+        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], , :, [$2])
+    fi
+
+    CPPFLAGS="$CPPFLAGS_SAVED"
+    LDFLAGS="$LDFLAGS_SAVED"
 fi
 
 ])
diff --git a/m4/boost.m4 b/m4/boost.m4
index 4a6e29c..a0894f3 100644
--- a/m4/boost.m4
+++ b/m4/boost.m4
@@ -1,5 +1,5 @@
 # boost.m4: Locate Boost headers and libraries for autoconf-based projects.
-# Copyright (C) 2007, 2008, 2009  Benoit Sigoure <tsuna@lrde.epita.fr>
+# Copyright (C) 2007-2011, 2014  Benoit Sigoure <tsuna@lrde.epita.fr>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -21,10 +21,14 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# serial 10
-# Original sources can be found at http://repo.or.cz/w/boost.m4.git
+m4_define([_BOOST_SERIAL], [m4_translit([
+# serial 26
+], [#
+], [])])
+
+# Original sources can be found at http://github.com/tsuna/boost.m4
 # You can fetch the latest version of the script by doing:
-#   wget 'http://repo.or.cz/w/boost.m4.git?a=blob_plain;f=build-aux/boost.m4;hb=HEAD' -O boost.m4
+#   wget http://github.com/tsuna/boost.m4/raw/master/build-aux/boost.m4
 
 # ------ #
 # README #
@@ -35,58 +39,108 @@
 # find the Boost headers of a given (optional) minimum version and it will
 # define BOOST_CPPFLAGS accordingly.  It will add an option --with-boost to
 # your configure so that users can specify non standard locations.
-# For more README and documentation, go to http://repo.or.cz/w/boost.m4.git
+# If the user's environment contains BOOST_ROOT and --with-boost was not
+# specified, --with-boost=$BOOST_ROOT is implicitly used.
+# For more README and documentation, go to http://github.com/tsuna/boost.m4
 # Note: THESE MACROS ASSUME THAT YOU USE LIBTOOL.  If you don't, don't worry,
 # simply read the README, it will show you what to do step by step.
 
-m4_pattern_forbid([^_?BOOST_])
+m4_pattern_forbid([^_?(BOOST|Boost)_])
 
 
 # _BOOST_SED_CPP(SED-PROGRAM, PROGRAM,
 #                [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
 # --------------------------------------------------------
 # Same as AC_EGREP_CPP, but leave the result in conftest.i.
-# PATTERN is *not* overquoted, as in AC_EGREP_CPP.  It could be useful
-# to turn this into a macro which extracts the value of any macro.
+#
+# SED-PROGRAM is *not* overquoted, as in AC_EGREP_CPP.  It is expanded
+# in double-quotes, so escape your double quotes.
+#
+# It could be useful to turn this into a macro which extracts the
+# value of any macro.
 m4_define([_BOOST_SED_CPP],
-[AC_LANG_PREPROC_REQUIRE()dnl
+[AC_LANG_PUSH([C++])dnl
+AC_LANG_PREPROC_REQUIRE()dnl
 AC_REQUIRE([AC_PROG_SED])dnl
 AC_LANG_CONFTEST([AC_LANG_SOURCE([[$2]])])
 AS_IF([dnl eval is necessary to expand ac_cpp.
 dnl Ultrix and Pyramid sh refuse to redirect output of eval, so use subshell.
+dnl Beware of Windows end-of-lines, for instance if we are running
+dnl some Windows programs under Wine.  In that case, boost/version.hpp
+dnl is certainly using "\r\n", but the regular Unix shell will only
+dnl strip `\n' with backquotes, not the `\r'.  This results in
+dnl boost_cv_lib_version='1_37\r' for instance, which breaks
+dnl everything else.
+dnl Cannot use 'dnl' after [$4] because a trailing dnl may break AC_CACHE_CHECK
+dnl
+dnl Beware that GCC 5, when expanding macros, may embed # line directives
+dnl a within single line:
+dnl
+dnl # 1 "conftest.cc"
+dnl # 1 "<built-in>"
+dnl # 1 "<command-line>"
+dnl # 1 "conftest.cc"
+dnl # 1 "/opt/local/include/boost/version.hpp" 1 3
+dnl # 2 "conftest.cc" 2
+dnl boost-lib-version =
+dnl # 2 "conftest.cc" 3
+dnl                    "1_56"
+dnl
+dnl So get rid of the # and empty lines, and glue the remaining ones together.
 (eval "$ac_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD |
+  grep -v '#' |
+  grep -v '^[[[:space:]]]*$' |
+  tr -d '\r' |
+  tr -s '\n' ' ' |
   $SED -n -e "$1" >conftest.i 2>&1],
   [$3],
-  [$4])dnl
-rm -f conftest*
-])# AC_EGREP_CPP
+  [$4])
+rm -rf conftest*
+AC_LANG_POP([C++])dnl
+])# _BOOST_SED_CPP
 
 
 
-# BOOST_REQUIRE([VERSION])
-# ------------------------
+# BOOST_REQUIRE([VERSION], [ACTION-IF-NOT-FOUND])
+# -----------------------------------------------
 # Look for Boost.  If version is given, it must either be a literal of the form
 # "X.Y.Z" where X, Y and Z are integers (the ".Z" part being optional) or a
 # variable "$var".
 # Defines the value BOOST_CPPFLAGS.  This macro only checks for headers with
 # the required version, it does not check for any of the Boost libraries.
-# FIXME: Add a 2nd optional argument so that it's not fatal if Boost isn't found
-# and add an AC_DEFINE to tell whether HAVE_BOOST.
-AC_DEFUN([BOOST_REQUIRE],
-[boost_save_IFS=$IFS
-boost_version_req="$1"
+# On # success, defines HAVE_BOOST.  On failure, calls the optional
+# ACTION-IF-NOT-FOUND action if one was supplied.
+# Otherwise aborts with an error message.
+AC_DEFUN_ONCE([BOOST_REQUIRE],
+[AC_REQUIRE([AC_PROG_CXX])dnl
+AC_REQUIRE([AC_PROG_GREP])dnl
+echo "$as_me: this is boost.m4[]_BOOST_SERIAL" >&AS_MESSAGE_LOG_FD
+boost_save_IFS=$IFS
+boost_version_req=$1
 IFS=.
 set x $boost_version_req 0 0 0
 IFS=$boost_save_IFS
 shift
 boost_version_req=`expr "$[1]" '*' 100000 + "$[2]" '*' 100 + "$[3]"`
+boost_version_req_string=$[1].$[2].$[3]
 AC_ARG_WITH([boost],
    [AS_HELP_STRING([--with-boost=DIR],
                    [prefix of Boost $1 @<:@guess@:>@])])dnl
+AC_ARG_VAR([BOOST_ROOT],[Location of Boost installation])dnl
+# If BOOST_ROOT is set and the user has not provided a value to
+# --with-boost, then treat BOOST_ROOT as if it the user supplied it.
+if test x"$BOOST_ROOT" != x; then
+  if test x"$with_boost" = x; then
+    AC_MSG_NOTICE([Detected BOOST_ROOT; continuing with --with-boost=$BOOST_ROOT])
+    with_boost=$BOOST_ROOT
+  else
+    AC_MSG_NOTICE([Detected BOOST_ROOT=$BOOST_ROOT, but overridden by --with-boost=$with_boost])
+  fi
+fi
 AC_SUBST([DISTCHECK_CONFIGURE_FLAGS],
-         ["$DISTCHECK_CONFIGURE_FLAGS '--with-boost=$with_boost'"])
+         ["$DISTCHECK_CONFIGURE_FLAGS '--with-boost=$with_boost'"])dnl
 boost_save_CPPFLAGS=$CPPFLAGS
-  AC_CACHE_CHECK([for Boost headers version >= $boost_version_req],
+  AC_CACHE_CHECK([for Boost headers version >= $boost_version_req_string],
     [boost_cv_inc_path],
     [boost_cv_inc_path=no
 AC_LANG_PUSH([C++])dnl
@@ -98,7 +152,7 @@ m4_pattern_allow([^BOOST_VERSION$])dnl
 # error Boost headers version < $boost_version_req
 #endif
 ]])])
-      # If the user provided a value to --with-boost, use it and only it.
+    # If the user provided a value to --with-boost, use it and only it.
     case $with_boost in #(
       ''|yes) set x '' /opt/local/include /usr/local/include /opt/include \
                  /usr/include C:/Boost/include;; #(
@@ -110,10 +164,37 @@ m4_pattern_allow([^BOOST_VERSION$])dnl
     # Without --layout=system, Boost (or at least some versions) installs
     # itself in <prefix>/include/boost-<version>.  This inner loop helps to
     # find headers in such directories.
+    #
+    # Any ${boost_dir}/boost-x_xx directories are searched in reverse version
+    # order followed by ${boost_dir}.  The final '.' is a sentinel for
+    # searching $boost_dir" itself.  Entries are whitespace separated.
+    #
     # I didn't indent this loop on purpose (to avoid over-indented code)
-    for boost_inc in "$boost_dir" "$boost_dir"/boost-*
+    boost_layout_system_search_list=`cd "$boost_dir" 2>/dev/null \
+        && ls -1 | "${GREP}" '^boost-' | sort -rn -t- -k2 \
+        && echo .`
+    for boost_inc in $boost_layout_system_search_list
     do
-      test x"$boost_inc" != x && CPPFLAGS="$CPPFLAGS -I$boost_inc"
+      if test x"$boost_inc" != x.; then
+        boost_inc="$boost_dir/$boost_inc"
+      else
+        boost_inc="$boost_dir" # Uses sentinel in boost_layout_system_search_list
+      fi
+      if test x"$boost_inc" != x; then
+        # We are going to check whether the version of Boost installed
+        # in $boost_inc is usable by running a compilation that
+        # #includes it.  But if we pass a -I/some/path in which Boost
+        # is not installed, the compiler will just skip this -I and
+        # use other locations (either from CPPFLAGS, or from its list
+        # of system include directories).  As a result we would use
+        # header installed on the machine instead of the /some/path
+        # specified by the user.  So in that precise case (trying
+        # $boost_inc), make sure the version.hpp exists.
+        #
+        # Use test -e as there can be symlinks.
+        test -e "$boost_inc/boost/version.hpp" || continue
+        CPPFLAGS="$CPPFLAGS -I$boost_inc"
+      fi
       AC_COMPILE_IFELSE([], [boost_cv_inc_path=yes], [boost_cv_version=no])
       if test x"$boost_cv_inc_path" = xyes; then
         if test x"$boost_inc" != x; then
@@ -126,51 +207,72 @@ m4_pattern_allow([^BOOST_VERSION$])dnl
 AC_LANG_POP([C++])dnl
     ])
     case $boost_cv_inc_path in #(
-      no)   AC_MSG_ERROR([cannot find Boost headers version >= $boost_version_req]);;#(
-      yes)  BOOST_CPPFLAGS=;;#(
-      *)    AC_SUBST([BOOST_CPPFLAGS], ["-I$boost_cv_inc_path"]);;
+      no)
+        boost_errmsg="cannot find Boost headers version >= $boost_version_req_string"
+        m4_if([$2], [],  [AC_MSG_ERROR([$boost_errmsg])],
+                        [AC_MSG_NOTICE([$boost_errmsg])])
+        $2
+        ;;#(
+      yes)
+        BOOST_CPPFLAGS=
+        ;;#(
+      *)
+        AC_SUBST([BOOST_CPPFLAGS], ["-I$boost_cv_inc_path"])dnl
+        ;;
     esac
+  if test x"$boost_cv_inc_path" != xno; then
+  AC_DEFINE([HAVE_BOOST], [1],
+            [Defined if the requested minimum BOOST version is satisfied])
   AC_CACHE_CHECK([for Boost's header version],
     [boost_cv_lib_version],
     [m4_pattern_allow([^BOOST_LIB_VERSION$])dnl
-     _BOOST_SED_CPP([/^boost-lib-version = /{s///;s/\"//g;p;g;}],
+     _BOOST_SED_CPP([[/^boost-lib-version = /{s///;s/[\" ]//g;p;q;}]],
                     [#include <boost/version.hpp>
 boost-lib-version = BOOST_LIB_VERSION],
     [boost_cv_lib_version=`cat conftest.i`])])
     # e.g. "134" for 1_34_1 or "135" for 1_35
     boost_major_version=`echo "$boost_cv_lib_version" | sed 's/_//;s/_.*//'`
     case $boost_major_version in #(
-      '' | *[[^0-9]]*)
-        AC_MSG_ERROR([Invalid value: boost_major_version=$boost_major_version])
+      '' | *[[!0-9]]*)
+        AC_MSG_ERROR([invalid value: boost_major_version='$boost_major_version'])
         ;;
     esac
+fi
 CPPFLAGS=$boost_save_CPPFLAGS
 ])# BOOST_REQUIRE
 
+
 # BOOST_STATIC()
 # --------------
 # Add the "--enable-static-boost" configure argument. If this argument is given
 # on the command line, static versions of the libraries will be looked up.
 AC_DEFUN([BOOST_STATIC],
   [AC_ARG_ENABLE([static-boost],
-     [AC_HELP_STRING([--enable-static-boost],
+     [AS_HELP_STRING([--enable-static-boost],
                [Prefer the static boost libraries over the shared ones [no]])],
      [enable_static_boost=yes],
      [enable_static_boost=no])])# BOOST_STATIC
 
+
 # BOOST_FIND_HEADER([HEADER-NAME], [ACTION-IF-NOT-FOUND], [ACTION-IF-FOUND])
 # --------------------------------------------------------------------------
 # Wrapper around AC_CHECK_HEADER for Boost headers.  Useful to check for
 # some parts of the Boost library which are only made of headers and don't
 # require linking (such as Boost.Foreach).
 #
-# Default ACTION-IF-NOT-FOUND: Fail with a fatal error.
+# Default ACTION-IF-NOT-FOUND: Fail with a fatal error unless Boost couldn't be
+# found in the first place, in which case by default a notice is issued to the
+# user.  Presumably if we haven't died already it's because it's OK to not have
+# Boost, which is why only a notice is issued instead of a hard error.
 #
 # Default ACTION-IF-FOUND: define the preprocessor symbol HAVE_<HEADER-NAME> in
 # case of success # (where HEADER-NAME is written LIKE_THIS, e.g.,
 # HAVE_BOOST_FOREACH_HPP).
 AC_DEFUN([BOOST_FIND_HEADER],
 [AC_REQUIRE([BOOST_REQUIRE])dnl
+if test x"$boost_cv_inc_path" = xno; then
+  m4_default([$2], [AC_MSG_NOTICE([Boost not available, not searching for $1])])
+else
 AC_LANG_PUSH([C++])dnl
 boost_save_CPPFLAGS=$CPPFLAGS
 CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
@@ -180,17 +282,20 @@ AC_CHECK_HEADER([$1],
   [m4_default([$2], [AC_MSG_ERROR([cannot find $1])])])
 CPPFLAGS=$boost_save_CPPFLAGS
 AC_LANG_POP([C++])dnl
+fi
 ])# BOOST_FIND_HEADER
 
 
-# BOOST_FIND_LIB([LIB-NAME], [PREFERRED-RT-OPT], [HEADER-NAME], [CXX-TEST],
-#                [CXX-PROLOGUE])
-# -------------------------------------------------------------------------
-# Look for the Boost library LIB-NAME (e.g., LIB-NAME = `thread', for
-# libboost_thread).  Check that HEADER-NAME works and check that
-# libboost_LIB-NAME can link with the code CXX-TEST.  The optional argument
-# CXX-PROLOGUE can be used to include some C++ code before the `main'
-# function.
+# BOOST_FIND_LIBS([COMPONENT-NAME], [CANDIDATE-LIB-NAMES],
+#                 [PREFERRED-RT-OPT], [HEADER-NAME], [CXX-TEST],
+#                 [CXX-PROLOGUE])
+# --------------------------------------------------------------
+# Look for the Boost library COMPONENT-NAME (e.g., `thread', for
+# libboost_thread) under the possible CANDIDATE-LIB-NAMES (e.g.,
+# "thread_win32 thread").  Check that HEADER-NAME works and check that
+# libboost_LIB-NAME can link with the code CXX-TEST.  The optional
+# argument CXX-PROLOGUE can be used to include some C++ code before
+# the `main' function.
 #
 # Invokes BOOST_FIND_HEADER([HEADER-NAME]) (see above).
 #
@@ -204,41 +309,83 @@ AC_LANG_POP([C++])dnl
 # builds.  Some sample values for PREFERRED-RT-OPT: (nothing), mt, d, mt-d, gdp
 # ...  If you want to make sure you have a specific version of Boost
 # (eg, >= 1.33) you *must* invoke BOOST_REQUIRE before this macro.
-AC_DEFUN([BOOST_FIND_LIB],
-[AC_REQUIRE([_BOOST_FIND_COMPILER_TAG])dnl
-AC_REQUIRE([BOOST_REQUIRE])dnl
+AC_DEFUN([BOOST_FIND_LIBS],
+[AC_REQUIRE([BOOST_REQUIRE])dnl
+AC_REQUIRE([_BOOST_FIND_COMPILER_TAG])dnl
 AC_REQUIRE([BOOST_STATIC])dnl
 AC_REQUIRE([_BOOST_GUESS_WHETHER_TO_USE_MT])dnl
+if test x"$boost_cv_inc_path" = xno; then
+  AC_MSG_NOTICE([Boost not available, not searching for the Boost $1 library])
+else
+dnl The else branch is huge and wasn't intended on purpose.
 AC_LANG_PUSH([C++])dnl
 AS_VAR_PUSHDEF([Boost_lib], [boost_cv_lib_$1])dnl
 AS_VAR_PUSHDEF([Boost_lib_LDFLAGS], [boost_cv_lib_$1_LDFLAGS])dnl
+AS_VAR_PUSHDEF([Boost_lib_LDPATH], [boost_cv_lib_$1_LDPATH])dnl
 AS_VAR_PUSHDEF([Boost_lib_LIBS], [boost_cv_lib_$1_LIBS])dnl
-BOOST_FIND_HEADER([$3])
+BOOST_FIND_HEADER([$4])
 boost_save_CPPFLAGS=$CPPFLAGS
 CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
-# Now let's try to find the library.  The algorithm is as follows: first look
-# for a given library name according to the user's PREFERRED-RT-OPT.  For each
-# library name, we prefer to use the ones that carry the tag (toolset name).
-# Each library is searched through the various standard paths were Boost is
-# usually installed.  If we can't find the standard variants, we try to
-# enforce -mt (for instance on MacOSX, libboost_threads.dylib doesn't exist
-# but there's -obviously- libboost_threads-mt.dylib).
 AC_CACHE_CHECK([for the Boost $1 library], [Boost_lib],
-  [Boost_lib=no
-  case "$2" in #(
-    mt | mt-) boost_mt=-mt; boost_rtopt=;; #(
-    mt* | mt-*) boost_mt=-mt; boost_rtopt=`expr "X$2" : 'Xmt-*\(.*\)'`;; #(
-    *) boost_mt=; boost_rtopt=$2;;
+               [_BOOST_FIND_LIBS($@)])
+case $Boost_lib in #(
+  (no) _AC_MSG_LOG_CONFTEST
+    AC_MSG_ERROR([cannot find the flags to link with Boost $1])
+    ;;
+esac
+AC_SUBST(AS_TR_CPP([BOOST_$1_LDFLAGS]), [$Boost_lib_LDFLAGS])dnl
+AC_SUBST(AS_TR_CPP([BOOST_$1_LDPATH]), [$Boost_lib_LDPATH])dnl
+AC_SUBST([BOOST_LDPATH], [$Boost_lib_LDPATH])dnl
+AC_SUBST(AS_TR_CPP([BOOST_$1_LIBS]), [$Boost_lib_LIBS])dnl
+CPPFLAGS=$boost_save_CPPFLAGS
+AS_VAR_POPDEF([Boost_lib])dnl
+AS_VAR_POPDEF([Boost_lib_LDFLAGS])dnl
+AS_VAR_POPDEF([Boost_lib_LDPATH])dnl
+AS_VAR_POPDEF([Boost_lib_LIBS])dnl
+AC_LANG_POP([C++])dnl
+fi
+])
+
+
+# BOOST_FIND_LIB([LIB-NAME],
+#                [PREFERRED-RT-OPT], [HEADER-NAME], [CXX-TEST],
+#                [CXX-PROLOGUE])
+# --------------------------------------------------------------
+# Backward compatibility wrapper for BOOST_FIND_LIBS.
+AC_DEFUN([BOOST_FIND_LIB],
+[BOOST_FIND_LIBS([$1], $@)])
+
+
+# _BOOST_FIND_LIBS([LIB-NAME], [CANDIDATE-LIB-NAMES],
+#                 [PREFERRED-RT-OPT], [HEADER-NAME], [CXX-TEST],
+#                 [CXX-PROLOGUE])
+# --------------------------------------------------------------
+# Real implementation of BOOST_FIND_LIBS: rely on these local macros:
+# Boost_lib, Boost_lib_LDFLAGS, Boost_lib_LDPATH, Boost_lib_LIBS
+#
+# The algorithm is as follows: first look for a given library name
+# according to the user's PREFERRED-RT-OPT.  For each library name, we
+# prefer to use the ones that carry the tag (toolset name).  Each
+# library is searched through the various standard paths were Boost is
+# usually installed.  If we can't find the standard variants, we try
+# to enforce -mt (for instance on MacOSX, libboost_thread.dylib
+# doesn't exist but there's -obviously- libboost_thread-mt.dylib).
+AC_DEFUN([_BOOST_FIND_LIBS],
+[Boost_lib=no
+  case "$3" in #(
+    (mt | mt-) boost_mt=-mt; boost_rtopt=;; #(
+    (mt* | mt-*) boost_mt=-mt; boost_rtopt=`expr "X$3" : 'Xmt-*\(.*\)'`;; #(
+    (*) boost_mt=; boost_rtopt=$3;;
   esac
   if test $enable_static_boost = yes; then
     boost_rtopt="s$boost_rtopt"
   fi
   # Find the proper debug variant depending on what we've been asked to find.
   case $boost_rtopt in #(
-    *d*) boost_rt_d=$boost_rtopt;; #(
-    *[[sgpn]]*) # Insert the `d' at the right place (in between `sg' and `pn')
+    (*d*) boost_rt_d=$boost_rtopt;; #(
+    (*[[sgpn]]*) # Insert the `d' at the right place (in between `sg' and `pn')
       boost_rt_d=`echo "$boost_rtopt" | sed 's/\(s*g*\)\(p*n*\)/\1\2/'`;; #(
-    *) boost_rt_d='-d';;
+    (*) boost_rt_d='-d';;
   esac
   # If the PREFERRED-RT-OPT are not empty, prepend a `-'.
   test -n "$boost_rtopt" && boost_rtopt="-$boost_rtopt"
@@ -249,8 +396,8 @@ AC_CACHE_CHECK([for the Boost $1 library], [Boost_lib],
     AC_MSG_ERROR([the libext variable is empty, did you invoke Libtool?])
   boost_save_ac_objext=$ac_objext
   # Generate the test file.
-  AC_LANG_CONFTEST([AC_LANG_PROGRAM([#include <$3>
-$5], [$4])])
+  AC_LANG_CONFTEST([AC_LANG_PROGRAM([#include <$4>
+$6], [$5])])
 dnl Optimization hacks: compiling C++ is slow, especially with Boost.  What
 dnl we're trying to do here is guess the right combination of link flags
 dnl (LIBS / LDFLAGS) to use a given library.  This can take several
@@ -269,41 +416,45 @@ dnl empty because the test file is generated only once above (before we
 dnl start the for loops).
   AC_COMPILE_IFELSE([],
     [ac_objext=do_not_rm_me_plz],
-    [AC_MSG_ERROR([Cannot compile a test that uses Boost $1])])
+    [AC_MSG_ERROR([cannot compile a test that uses Boost $1])])
   ac_objext=$boost_save_ac_objext
   boost_failed_libs=
-# Don't bother to ident the 6 nested for loops, only the 2 innermost ones
-# matter.
+# Don't bother to ident the following nested for loops, only the 2
+# innermost ones matter.
+for boost_lib_ in $2; do
 for boost_tag_ in -$boost_cv_lib_tag ''; do
 for boost_ver_ in -$boost_cv_lib_version ''; do
 for boost_mt_ in $boost_mt -mt ''; do
 for boost_rtopt_ in $boost_rtopt '' -d; do
   for boost_lib in \
-    boost_$1$boost_tag_$boost_mt_$boost_rtopt_$boost_ver_ \
-    boost_$1$boost_tag_$boost_rtopt_$boost_ver_ \
-    boost_$1$boost_tag_$boost_mt_$boost_ver_ \
-    boost_$1$boost_tag_$boost_ver_
+    boost_$boost_lib_$boost_tag_$boost_mt_$boost_rtopt_$boost_ver_ \
+    boost_$boost_lib_$boost_tag_$boost_rtopt_$boost_ver_ \
+    boost_$boost_lib_$boost_tag_$boost_mt_$boost_ver_ \
+    boost_$boost_lib_$boost_tag_$boost_ver_
   do
     # Avoid testing twice the same lib
     case $boost_failed_libs in #(
-      *@$boost_lib@*) continue;;
+      (*@$boost_lib@*) continue;;
     esac
     # If with_boost is empty, we'll search in /lib first, which is not quite
     # right so instead we'll try to a location based on where the headers are.
     boost_tmp_lib=$with_boost
     test x"$with_boost" = x && boost_tmp_lib=${boost_cv_inc_path%/include}
     for boost_ldpath in "$boost_tmp_lib/lib" '' \
-             /opt/local/lib /usr/local/lib /opt/lib /usr/lib \
-             "$with_boost" C:/Boost/lib /lib /usr/lib64 /lib64
+             /opt/local/lib* /usr/local/lib* /opt/lib* /usr/lib* \
+             "$with_boost" C:/Boost/lib /lib*
     do
-      test -e "$boost_ldpath" || continue
+      # Don't waste time with directories that don't exist.
+      if test x"$boost_ldpath" != x && test ! -e "$boost_ldpath"; then
+        continue
+      fi
       boost_save_LDFLAGS=$LDFLAGS
       # Are we looking for a static library?
       case $boost_ldpath:$boost_rtopt_ in #(
-        *?*:*s*) # Yes (Non empty boost_ldpath + s in rt opt)
+        (*?*:*s*) # Yes (Non empty boost_ldpath + s in rt opt)
           Boost_lib_LIBS="$boost_ldpath/lib$boost_lib.$libext"
           test -e "$Boost_lib_LIBS" || continue;; #(
-        *) # No: use -lboost_foo to find the shared library.
+        (*) # No: use -lboost_foo to find the shared library.
           Boost_lib_LIBS="-l$boost_lib";;
       esac
       boost_save_LIBS=$LIBS
@@ -317,8 +468,35 @@ dnl generated only once above (before we start the for loops).
       LDFLAGS=$boost_save_LDFLAGS
       LIBS=$boost_save_LIBS
       if test x"$Boost_lib" = xyes; then
-        Boost_lib_LDFLAGS="-L$boost_ldpath -R$boost_ldpath"
-        break 6
+        # Check or used cached result of whether or not using -R or
+        # -rpath makes sense.  Some implementations of ld, such as for
+        # Mac OSX, require -rpath but -R is the flag known to work on
+        # other systems.  https://github.com/tsuna/boost.m4/issues/19
+        AC_CACHE_VAL([boost_cv_rpath_link_ldflag],
+          [case $boost_ldpath in
+           '') # Nothing to do.
+             boost_cv_rpath_link_ldflag=
+             boost_rpath_link_ldflag_found=yes;;
+           *)
+            for boost_cv_rpath_link_ldflag in -Wl,-R, -Wl,-rpath,; do
+              LDFLAGS="$boost_save_LDFLAGS -L$boost_ldpath $boost_cv_rpath_link_ldflag$boost_ldpath"
+              LIBS="$boost_save_LIBS $Boost_lib_LIBS"
+              _BOOST_AC_LINK_IFELSE([],
+                [boost_rpath_link_ldflag_found=yes
+                break],
+                [boost_rpath_link_ldflag_found=no])
+            done
+            ;;
+          esac
+          AS_IF([test "x$boost_rpath_link_ldflag_found" != "xyes"],
+            [AC_MSG_ERROR([Unable to determine whether to use -R or -rpath])])
+          LDFLAGS=$boost_save_LDFLAGS
+          LIBS=$boost_save_LIBS
+          ])
+        test x"$boost_ldpath" != x &&
+          Boost_lib_LDFLAGS="-L$boost_ldpath $boost_cv_rpath_link_ldflag$boost_ldpath"
+        Boost_lib_LDPATH="$boost_ldpath"
+        break 7
       else
         boost_failed_libs="$boost_failed_libs@$boost_lib@"
       fi
@@ -328,20 +506,10 @@ done
 done
 done
 done
+done # boost_lib_
 rm -f conftest.$ac_objext
 ])
-case $Boost_lib in #(
-  no) AC_MSG_ERROR([Could not find the flags to link with Boost $1])
-    ;;
-esac
-AC_SUBST(AS_TR_CPP([BOOST_$1_LDFLAGS]), [$Boost_lib_LDFLAGS])
-AC_SUBST(AS_TR_CPP([BOOST_$1_LIBS]), [$Boost_lib_LIBS])
-CPPFLAGS=$boost_save_CPPFLAGS
-AS_VAR_POPDEF([Boost_lib])dnl
-AS_VAR_POPDEF([Boost_lib_LDFLAGS])dnl
-AS_VAR_POPDEF([Boost_lib_LIBS])dnl
-AC_LANG_POP([C++])dnl
-])# BOOST_FIND_LIB
+
 
 
 # --------------------------------------- #
@@ -352,36 +520,225 @@ AC_LANG_POP([C++])dnl
 # The page http://beta.boost.org/doc/libs is useful: it gives the first release
 # version of each library (among other things).
 
+# BOOST_DEFUN(LIBRARY, CODE)
+# --------------------------
+# Define BOOST_<LIBRARY-UPPERCASE> as a macro that runs CODE.
+#
+# Use indir to avoid the warning on underquoted macro name given to AC_DEFUN.
+m4_define([BOOST_DEFUN],
+[m4_indir([AC_DEFUN],
+          m4_toupper([BOOST_$1]),
+[m4_pushdef([BOOST_Library], [$1])dnl
+$2
+m4_popdef([BOOST_Library])dnl
+])
+])
+
+# BOOST_ARRAY()
+# -------------
+# Look for Boost.Array
+BOOST_DEFUN([Array],
+[BOOST_FIND_HEADER([boost/array.hpp])])
+
 
 # BOOST_ASIO()
 # ------------
 # Look for Boost.Asio (new in Boost 1.35).
-AC_DEFUN([BOOST_ASIO],
+BOOST_DEFUN([Asio],
 [AC_REQUIRE([BOOST_SYSTEM])dnl
 BOOST_FIND_HEADER([boost/asio.hpp])])
 
 
+# BOOST_ASSIGN()
+# -------------
+# Look for Boost.Assign
+BOOST_DEFUN([Assign],
+[BOOST_FIND_HEADER([boost/assign.hpp])])
+
+
 # BOOST_BIND()
 # ------------
-# Look for Boost.Bind
-AC_DEFUN([BOOST_BIND],
+# Look for Boost.Bind.
+BOOST_DEFUN([Bind],
 [BOOST_FIND_HEADER([boost/bind.hpp])])
 
 
+# BOOST_CHRONO()
+# --------------
+# Look for Boost.Chrono.
+BOOST_DEFUN([Chrono],
+[# Do we have to check for Boost.System?  This link-time dependency was
+# added as of 1.35.0.  If we have a version <1.35, we must not attempt to
+# find Boost.System as it didn't exist by then.
+if test $boost_major_version -ge 135; then
+  BOOST_SYSTEM([$1])
+fi # end of the Boost.System check.
+boost_filesystem_save_LIBS=$LIBS
+boost_filesystem_save_LDFLAGS=$LDFLAGS
+m4_pattern_allow([^BOOST_SYSTEM_(LIBS|LDFLAGS)$])dnl
+LIBS="$LIBS $BOOST_SYSTEM_LIBS"
+LDFLAGS="$LDFLAGS $BOOST_SYSTEM_LDFLAGS"
+BOOST_FIND_LIB([chrono], [$1],
+                [boost/chrono.hpp],
+                [boost::chrono::thread_clock d;])
+if test $enable_static_boost = yes && test $boost_major_version -ge 135; then
+  BOOST_CHRONO_LIBS="$BOOST_CHRONO_LIBS $BOOST_SYSTEM_LIBS"
+fi
+LIBS=$boost_filesystem_save_LIBS
+LDFLAGS=$boost_filesystem_save_LDFLAGS
+])# BOOST_CHRONO
+
+
+# BOOST_CONTEXT([PREFERRED-RT-OPT])
+# -----------------------------------
+# Look for Boost.Context.  For the documentation of PREFERRED-RT-OPT, see the
+# documentation of BOOST_FIND_LIB above.
+#
+# * This library was introduced in Boost 1.51.0
+# * The signatures of make_fcontext() and jump_fcontext were changed in 1.56.0
+# * A dependency on boost_thread appears in 1.57.0
+BOOST_DEFUN([Context],
+[boost_context_save_LIBS=$LIBS
+ boost_context_save_LDFLAGS=$LDFLAGS
+if test $boost_major_version -ge 157; then
+  BOOST_THREAD([$1])
+  m4_pattern_allow([^BOOST_THREAD_(LIBS|LDFLAGS)$])dnl
+  LIBS="$LIBS $BOOST_THREAD_LIBS"
+  LDFLAGS="$LDFLAGS $BOOST_THREAD_LDFLAGS"
+fi
+BOOST_FIND_LIB([context], [$1],
+                [boost/context/all.hpp],[[
+
+// creates a stack
+void * stack_pointer = new void*[4096];
+std::size_t const size = sizeof(void*[4096]);
+
+#if BOOST_VERSION <= 105100
+ctx::make_fcontext(&fc, f);
+return ctx::jump_fcontext(&fcm, &fc, 3) == 6;
+
+#else
+
+fc = ctx::make_fcontext(stack_pointer, size, f);
+return ctx::jump_fcontext(&fcm, fc, 3) == 6;
+
+#endif
+
+
+]],[dnl
+
+#include <boost/version.hpp>
+#if BOOST_VERSION <= 105100
+
+namespace ctx = boost::ctx;
+
+static ctx::fcontext_t fcm, fc;
+
+static void f(intptr_t i) {
+    ctx::jump_fcontext(&fc, &fcm, i * 2);
+}
+
+#elif BOOST_VERSION <= 105500
+
+namespace ctx = boost::context;
+
+// context
+static ctx::fcontext_t fcm, *fc;
+
+// context-function
+static void f(intptr_t i) {
+    ctx::jump_fcontext(fc, &fcm, i * 2);
+}
+
+#else
+
+namespace ctx = boost::context;
+
+// context
+static ctx::fcontext_t fcm, fc;
+
+// context-function
+static void f(intptr_t i) {
+    ctx::jump_fcontext(&fc, fcm, i * 2);
+}
+#endif
+])
+LIBS=$boost_context_save_LIBS
+LDFLAGS=$boost_context_save_LDFLAGS
+])# BOOST_CONTEXT
+
+
 # BOOST_CONVERSION()
 # ------------------
 # Look for Boost.Conversion (cast / lexical_cast)
-AC_DEFUN([BOOST_CONVERSION],
+BOOST_DEFUN([Conversion],
 [BOOST_FIND_HEADER([boost/cast.hpp])
 BOOST_FIND_HEADER([boost/lexical_cast.hpp])
 ])# BOOST_CONVERSION
 
 
+# BOOST_COROUTINE([PREFERRED-RT-OPT])
+# -----------------------------------
+# Look for Boost.Coroutine.  For the documentation of PREFERRED-RT-OPT, see the
+# documentation of BOOST_FIND_LIB above.  This library was introduced in Boost
+# 1.53.0
+BOOST_DEFUN([Coroutine],
+[
+boost_coroutine_save_LIBS=$LIBS
+boost_coroutine_save_LDFLAGS=$LDFLAGS
+# Link-time dependency from coroutine to context
+BOOST_CONTEXT([$1])
+# Starting from Boost 1.55 a dependency on Boost.System is added
+if test $boost_major_version -ge 155; then
+  BOOST_SYSTEM([$1])
+fi
+m4_pattern_allow([^BOOST_(CONTEXT|SYSTEM)_(LIBS|LDFLAGS)])
+LIBS="$LIBS $BOOST_CONTEXT_LIBS $BOOST_SYSTEM_LIBS"
+LDFLAGS="$LDFLAGS $BOOST_CONTEXT_LDFLAGS"
+
+# in 1.53 coroutine was a header only library
+if test $boost_major_version -eq 153; then
+  BOOST_FIND_HEADER([boost/coroutine/coroutine.hpp])
+else
+  BOOST_FIND_LIB([coroutine], [$1],
+		  [boost/coroutine/coroutine.hpp],
+		  [
+  #include <boost/version.hpp>
+  #if   BOOST_VERSION <= 105500
+  boost::coroutines::coroutine<int(int)> coro; coro.get();
+  #else
+  boost::coroutines::asymmetric_coroutine<int>::pull_type coro; coro.get();
+  #endif
+  ])
+fi
+# Link-time dependency from coroutine to context, existed only in 1.53, in 1.54
+# coroutine doesn't use context from its headers but from its library.
+if test $boost_major_version -eq 153 || test $enable_static_boost = yes && test $boost_major_version -ge 154; then
+  BOOST_COROUTINE_LIBS="$BOOST_COROUTINE_LIBS $BOOST_CONTEXT_LIBS"
+  BOOST_COROUTINE_LDFLAGS="$BOOST_COROUTINE_LDFLAGS $BOOST_CONTEXT_LDFLAGS"
+fi
+if test $enable_static_boost = yes && test $boost_major_version -ge 155; then
+  BOOST_COROUTINE_LIBS="$BOOST_COROUTINE_LIBS $BOOST_SYSTEM_LIBS"
+  BOOST_COROUTINE_LDFLAGS="$BOOST_COROUTINE_LDFLAGS $BOOST_SYSTEM_LDFLAGS"
+fi
+LIBS=$boost_coroutine_save_LIBS
+LDFLAGS=$boost_coroutine_save_LDFLAGS
+])# BOOST_COROUTINE
+
+
+# BOOST_CRC()
+# -----------
+# Look for Boost.CRC
+BOOST_DEFUN([CRC],
+[BOOST_FIND_HEADER([boost/crc.hpp])
+])# BOOST_CRC
+
+
 # BOOST_DATE_TIME([PREFERRED-RT-OPT])
 # -----------------------------------
 # Look for Boost.Date_Time.  For the documentation of PREFERRED-RT-OPT, see the
 # documentation of BOOST_FIND_LIB above.
-AC_DEFUN([BOOST_DATE_TIME],
+BOOST_DEFUN([Date_Time],
 [BOOST_FIND_LIB([date_time], [$1],
                 [boost/date_time/posix_time/posix_time.hpp],
                 [boost::posix_time::ptime t;])
@@ -394,12 +751,12 @@ AC_DEFUN([BOOST_DATE_TIME],
 # the documentation of BOOST_FIND_LIB above.
 # Do not check for boost/filesystem.hpp because this file was introduced in
 # 1.34.
-AC_DEFUN([BOOST_FILESYSTEM],
+BOOST_DEFUN([Filesystem],
 [# Do we have to check for Boost.System?  This link-time dependency was
 # added as of 1.35.0.  If we have a version <1.35, we must not attempt to
 # find Boost.System as it didn't exist by then.
 if test $boost_major_version -ge 135; then
-BOOST_SYSTEM([$1])
+  BOOST_SYSTEM([$1])
 fi # end of the Boost.System check.
 boost_filesystem_save_LIBS=$LIBS
 boost_filesystem_save_LDFLAGS=$LDFLAGS
@@ -408,93 +765,302 @@ LIBS="$LIBS $BOOST_SYSTEM_LIBS"
 LDFLAGS="$LDFLAGS $BOOST_SYSTEM_LDFLAGS"
 BOOST_FIND_LIB([filesystem], [$1],
                 [boost/filesystem/path.hpp], [boost::filesystem::path p;])
+if test $enable_static_boost = yes && test $boost_major_version -ge 135; then
+  BOOST_FILESYSTEM_LIBS="$BOOST_FILESYSTEM_LIBS $BOOST_SYSTEM_LIBS"
+fi
 LIBS=$boost_filesystem_save_LIBS
 LDFLAGS=$boost_filesystem_save_LDFLAGS
 ])# BOOST_FILESYSTEM
 
 
+# BOOST_FLYWEIGHT()
+# -----------------
+# Look for Boost.Flyweight.
+BOOST_DEFUN([Flyweight],
+[dnl There's a hidden dependency on pthreads.
+AC_REQUIRE([_BOOST_PTHREAD_FLAG])dnl
+BOOST_FIND_HEADER([boost/flyweight.hpp])
+AC_SUBST([BOOST_FLYWEIGHT_LIBS], [$boost_cv_pthread_flag])
+])
+
+
 # BOOST_FOREACH()
 # ---------------
-# Look for Boost.Foreach
-AC_DEFUN([BOOST_FOREACH],
+# Look for Boost.Foreach.
+BOOST_DEFUN([Foreach],
 [BOOST_FIND_HEADER([boost/foreach.hpp])])
 
 
 # BOOST_FORMAT()
 # --------------
-# Look for Boost.Format
+# Look for Boost.Format.
 # Note: we can't check for boost/format/format_fwd.hpp because the header isn't
 # standalone.  It can't be compiled because it triggers the following error:
 # boost/format/detail/config_macros.hpp:88: error: 'locale' in namespace 'std'
 #                                                  does not name a type
-AC_DEFUN([BOOST_FORMAT],
+BOOST_DEFUN([Format],
 [BOOST_FIND_HEADER([boost/format.hpp])])
 
 
 # BOOST_FUNCTION()
 # ----------------
 # Look for Boost.Function
-AC_DEFUN([BOOST_FUNCTION],
+BOOST_DEFUN([Function],
 [BOOST_FIND_HEADER([boost/function.hpp])])
 
 
+# BOOST_GEOMETRY()
+# ----------------
+# Look for Boost.Geometry (new since 1.47.0).
+BOOST_DEFUN([Geometry],
+[BOOST_FIND_HEADER([boost/geometry.hpp])
+])# BOOST_GEOMETRY
+
+
 # BOOST_GRAPH([PREFERRED-RT-OPT])
 # -------------------------------
 # Look for Boost.Graphs.  For the documentation of PREFERRED-RT-OPT, see the
 # documentation of BOOST_FIND_LIB above.
-AC_DEFUN([BOOST_GRAPH],
-[BOOST_FIND_LIB([graph], [$1],
+BOOST_DEFUN([Graph],
+[boost_graph_save_LIBS=$LIBS
+boost_graph_save_LDFLAGS=$LDFLAGS
+# Link-time dependency from graph to regex was added as of 1.40.0.
+if test $boost_major_version -ge 140; then
+  BOOST_REGEX([$1])
+  m4_pattern_allow([^BOOST_REGEX_(LIBS|LDFLAGS)$])dnl
+  LIBS="$LIBS $BOOST_REGEX_LIBS"
+  LDFLAGS="$LDFLAGS $BOOST_REGEX_LDFLAGS"
+fi
+BOOST_FIND_LIB([graph], [$1],
                 [boost/graph/adjacency_list.hpp], [boost::adjacency_list<> g;])
+LIBS=$boost_graph_save_LIBS
+LDFLAGS=$boost_graph_save_LDFLAGS
 ])# BOOST_GRAPH
 
 
 # BOOST_IOSTREAMS([PREFERRED-RT-OPT])
-# -------------------------------
+# -----------------------------------
 # Look for Boost.IOStreams.  For the documentation of PREFERRED-RT-OPT, see the
 # documentation of BOOST_FIND_LIB above.
-AC_DEFUN([BOOST_IOSTREAMS],
+BOOST_DEFUN([IOStreams],
 [BOOST_FIND_LIB([iostreams], [$1],
                 [boost/iostreams/device/file_descriptor.hpp],
-                [boost::iostreams::file_descriptor fd(0); fd.close();])
+                [boost::iostreams::file_descriptor fd; fd.close();])
 ])# BOOST_IOSTREAMS
 
 
 # BOOST_HASH()
 # ------------
 # Look for Boost.Functional/Hash
-AC_DEFUN([BOOST_HASH],
+BOOST_DEFUN([Hash],
 [BOOST_FIND_HEADER([boost/functional/hash.hpp])])
 
 
 # BOOST_LAMBDA()
 # --------------
 # Look for Boost.Lambda
-AC_DEFUN([BOOST_LAMBDA],
+BOOST_DEFUN([Lambda],
 [BOOST_FIND_HEADER([boost/lambda/lambda.hpp])])
 
 
+# BOOST_LOCALE()
+# --------------
+# Look for Boost.Locale
+BOOST_DEFUN([Locale],
+[
+boost_locale_save_LIBS=$LIBS
+boost_locale_save_LDFLAGS=$LDFLAGS
+# require SYSTEM for boost-1.50.0 and up
+if test $boost_major_version -ge 150; then
+  BOOST_SYSTEM([$1])
+  m4_pattern_allow([^BOOST_SYSTEM_(LIBS|LDFLAGS)$])dnl
+  LIBS="$LIBS $BOOST_SYSTEM_LIBS"
+  LDFLAGS="$LDFLAGS $BOOST_SYSTEM_LDFLAGS"
+fi # end of the Boost.System check.
+BOOST_FIND_LIB([locale], [$1],
+    [boost/locale.hpp],
+    [[boost::locale::generator gen; std::locale::global(gen(""));]])
+LIBS=$boost_locale_save_LIBS
+LDFLAGS=$boost_locale_save_LDFLAGS
+])# BOOST_LOCALE
+
+# BOOST_LOG([PREFERRED-RT-OPT])
+# -----------------------------
+# Look for Boost.Log.  For the documentation of PREFERRED-RT-OPT, see the
+# documentation of BOOST_FIND_LIB above.
+BOOST_DEFUN([Log],
+[boost_log_save_LIBS=$LIBS
+boost_log_save_LDFLAGS=$LDFLAGS
+BOOST_SYSTEM([$1])
+BOOST_FILESYSTEM([$1])
+BOOST_DATE_TIME([$1])
+m4_pattern_allow([^BOOST_(SYSTEM|FILESYSTEM|DATE_TIME)_(LIBS|LDFLAGS)$])dnl
+LIBS="$LIBS $BOOST_DATE_TIME_LIBS $BOOST_FILESYSTEM_LIBS $BOOST_SYSTEM_LIBS"
+LDFLAGS="$LDFLAGS $BOOST_DATE_TIME_LDFLAGS $BOOST_FILESYSTEM_LDFLAGS $BOOST_SYSTEM_LDFLAGS"
+BOOST_FIND_LIB([log], [$1],
+    [boost/log/core/core.hpp],
+    [boost::log::attribute a; a.get_value();])
+LIBS=$boost_log_save_LIBS
+LDFLAGS=$boost_log_save_LDFLAGS
+])# BOOST_LOG
+
+
+# BOOST_LOG_SETUP([PREFERRED-RT-OPT])
+# -----------------------------------
+# Look for Boost.Log.  For the documentation of PREFERRED-RT-OPT, see the
+# documentation of BOOST_FIND_LIB above.
+BOOST_DEFUN([Log_Setup],
+[boost_log_setup_save_LIBS=$LIBS
+boost_log_setup_save_LDFLAGS=$LDFLAGS
+BOOST_LOG([$1])
+m4_pattern_allow([^BOOST_LOG_(LIBS|LDFLAGS)$])dnl
+LIBS="$LIBS $BOOST_LOG_LIBS"
+LDFLAGS="$LDFLAGS $BOOST_LOG_LDFLAGS"
+BOOST_FIND_LIB([log_setup], [$1],
+    [boost/log/utility/setup/from_settings.hpp],
+    [boost::log::basic_settings<char> bs; bs.empty();])
+LIBS=$boost_log_setup_save_LIBS
+LDFLAGS=$boost_log_setup_save_LDFLAGS
+])# BOOST_LOG_SETUP
+
+
+# BOOST_MATH()
+# ------------
+# Look for Boost.Math
+# TODO: This library isn't header-only but it comes in multiple different
+# flavors that don't play well with BOOST_FIND_LIB (e.g, libboost_math_c99,
+# libboost_math_c99f, libboost_math_c99l, libboost_math_tr1,
+# libboost_math_tr1f, libboost_math_tr1l).  This macro must be fixed to do the
+# right thing anyway.
+BOOST_DEFUN([Math],
+[BOOST_FIND_HEADER([boost/math/special_functions.hpp])])
+
+
+# BOOST_MPI([PREFERRED-RT-OPT])
+# -------------------------------
+# Look for Boost MPI.  For the documentation of PREFERRED-RT-OPT, see the
+# documentation of BOOST_FIND_LIB above.  Uses MPICXX variable if it is
+# set, otherwise tries CXX
+#
+BOOST_DEFUN([MPI],
+[boost_save_CXX=${CXX}
+boost_save_CXXCPP=${CXXCPP}
+if test x"${MPICXX}" != x; then
+  CXX=${MPICXX}
+  CXXCPP="${MPICXX} -E"
+fi
+BOOST_FIND_LIB([mpi], [$1],
+               [boost/mpi.hpp],
+               [int argc = 0;
+                char **argv = 0;
+                boost::mpi::environment env(argc,argv);])
+CXX=${boost_save_CXX}
+CXXCPP=${boost_save_CXXCPP}
+])# BOOST_MPI
+
+
+# BOOST_MULTIARRAY()
+# ------------------
+# Look for Boost.MultiArray
+BOOST_DEFUN([MultiArray],
+[BOOST_FIND_HEADER([boost/multi_array.hpp])])
+
+
+# BOOST_NUMERIC_UBLAS()
+# --------------------------
+# Look for Boost.NumericUblas (Basic Linear Algebra)
+BOOST_DEFUN([Numeric_Ublas],
+[BOOST_FIND_HEADER([boost/numeric/ublas/vector.hpp])
+])# BOOST_NUMERIC_UBLAS
+
+
+# BOOST_NUMERIC_CONVERSION()
+# --------------------------
+# Look for Boost.NumericConversion (policy-based numeric conversion)
+BOOST_DEFUN([Numeric_Conversion],
+[BOOST_FIND_HEADER([boost/numeric/conversion/converter.hpp])
+])# BOOST_NUMERIC_CONVERSION
+
+
+# BOOST_OPTIONAL()
+# ----------------
+# Look for Boost.Optional
+BOOST_DEFUN([Optional],
+[BOOST_FIND_HEADER([boost/optional.hpp])])
+
+
 # BOOST_PREPROCESSOR()
 # --------------------
 # Look for Boost.Preprocessor
-AC_DEFUN([BOOST_PREPROCESSOR],
+BOOST_DEFUN([Preprocessor],
 [BOOST_FIND_HEADER([boost/preprocessor/repeat.hpp])])
 
 
+# BOOST_RANGE()
+# --------------------
+# Look for Boost.Range
+BOOST_DEFUN([Range],
+[BOOST_FIND_HEADER([boost/range/adaptors.hpp])])
+
+# BOOST_UNORDERED()
+# -----------------
+# Look for Boost.Unordered
+BOOST_DEFUN([Unordered],
+[BOOST_FIND_HEADER([boost/unordered_map.hpp])])
+
+
+# BOOST_UUID()
+# ------------
+# Look for Boost.Uuid
+BOOST_DEFUN([Uuid],
+[BOOST_FIND_HEADER([boost/uuid/uuid.hpp])])
+
+
 # BOOST_PROGRAM_OPTIONS([PREFERRED-RT-OPT])
 # -----------------------------------------
-# Look for Boost.Program_options.  For the documentation of PREFERRED-RT-OPT, see
-# the documentation of BOOST_FIND_LIB above.
-AC_DEFUN([BOOST_PROGRAM_OPTIONS],
+# Look for Boost.Program_options.  For the documentation of PREFERRED-RT-OPT,
+# see the documentation of BOOST_FIND_LIB above.
+BOOST_DEFUN([Program_Options],
 [BOOST_FIND_LIB([program_options], [$1],
                 [boost/program_options.hpp],
                 [boost::program_options::options_description d("test");])
 ])# BOOST_PROGRAM_OPTIONS
 
 
+
+# _BOOST_PYTHON_CONFIG(VARIABLE, FLAG)
+# ------------------------------------
+# Save VARIABLE, and define it via `python-config --FLAG`.
+# Substitute BOOST_PYTHON_VARIABLE.
+m4_define([_BOOST_PYTHON_CONFIG],
+[AC_SUBST([BOOST_PYTHON_$1],
+          [`python-config --$2 2>/dev/null`])dnl
+boost_python_save_$1=$$1
+$1="$$1 $BOOST_PYTHON_$1"])
+
+
+# BOOST_PYTHON([PREFERRED-RT-OPT])
+# --------------------------------
+# Look for Boost.Python.  For the documentation of PREFERRED-RT-OPT,
+# see the documentation of BOOST_FIND_LIB above.
+BOOST_DEFUN([Python],
+[_BOOST_PYTHON_CONFIG([CPPFLAGS], [includes])
+_BOOST_PYTHON_CONFIG([LDFLAGS],   [ldflags])
+_BOOST_PYTHON_CONFIG([LIBS],      [libs])
+m4_pattern_allow([^BOOST_PYTHON_MODULE$])dnl
+BOOST_FIND_LIBS([python], [python python3], [$1],
+                [boost/python.hpp],
+                [], [BOOST_PYTHON_MODULE(empty) {}])
+CPPFLAGS=$boost_python_save_CPPFLAGS
+LDFLAGS=$boost_python_save_LDFLAGS
+LIBS=$boost_python_save_LIBS
+])# BOOST_PYTHON
+
+
 # BOOST_REF()
 # -----------
 # Look for Boost.Ref
-AC_DEFUN([BOOST_REF],
+BOOST_DEFUN([Ref],
 [BOOST_FIND_HEADER([boost/ref.hpp])])
 
 
@@ -502,7 +1068,7 @@ AC_DEFUN([BOOST_REF],
 # -------------------------------
 # Look for Boost.Regex.  For the documentation of PREFERRED-RT-OPT, see the
 # documentation of BOOST_FIND_LIB above.
-AC_DEFUN([BOOST_REGEX],
+BOOST_DEFUN([Regex],
 [BOOST_FIND_LIB([regex], [$1],
                 [boost/regex.hpp],
                 [boost::regex exp("*"); boost::regex_match("foo", exp);])
@@ -513,38 +1079,53 @@ AC_DEFUN([BOOST_REGEX],
 # ---------------------------------------
 # Look for Boost.Serialization.  For the documentation of PREFERRED-RT-OPT, see
 # the documentation of BOOST_FIND_LIB above.
-AC_DEFUN([BOOST_SERIALIZATION],
+BOOST_DEFUN([Serialization],
 [BOOST_FIND_LIB([serialization], [$1],
                 [boost/archive/text_oarchive.hpp],
                 [std::ostream* o = 0; // Cheap way to get an ostream...
                 boost::archive::text_oarchive t(*o);])
-])# BOOST_SIGNALS
+])# BOOST_SERIALIZATION
 
 
 # BOOST_SIGNALS([PREFERRED-RT-OPT])
 # ---------------------------------
 # Look for Boost.Signals.  For the documentation of PREFERRED-RT-OPT, see the
 # documentation of BOOST_FIND_LIB above.
-AC_DEFUN([BOOST_SIGNALS],
+BOOST_DEFUN([Signals],
 [BOOST_FIND_LIB([signals], [$1],
                 [boost/signal.hpp],
                 [boost::signal<void ()> s;])
 ])# BOOST_SIGNALS
 
 
+# BOOST_SIGNALS2()
+# ----------------
+# Look for Boost.Signals2 (new since 1.39.0).
+BOOST_DEFUN([Signals2],
+[BOOST_FIND_HEADER([boost/signals2.hpp])
+])# BOOST_SIGNALS2
+
+
 # BOOST_SMART_PTR()
 # -----------------
 # Look for Boost.SmartPtr
-AC_DEFUN([BOOST_SMART_PTR],
+BOOST_DEFUN([Smart_Ptr],
 [BOOST_FIND_HEADER([boost/scoped_ptr.hpp])
 BOOST_FIND_HEADER([boost/shared_ptr.hpp])
 ])
 
 
+# BOOST_STATICASSERT()
+# --------------------
+# Look for Boost.StaticAssert
+BOOST_DEFUN([StaticAssert],
+[BOOST_FIND_HEADER([boost/static_assert.hpp])])
+
+
 # BOOST_STRING_ALGO()
 # -------------------
 # Look for Boost.StringAlgo
-AC_DEFUN([BOOST_STRING_ALGO],
+BOOST_DEFUN([String_Algo],
 [BOOST_FIND_HEADER([boost/algorithm/string.hpp])
 ])
 
@@ -554,7 +1135,7 @@ AC_DEFUN([BOOST_STRING_ALGO],
 # Look for Boost.System.  For the documentation of PREFERRED-RT-OPT, see the
 # documentation of BOOST_FIND_LIB above.  This library was introduced in Boost
 # 1.35.0.
-AC_DEFUN([BOOST_SYSTEM],
+BOOST_DEFUN([System],
 [BOOST_FIND_LIB([system], [$1],
                 [boost/system/error_code.hpp],
                 [boost::system::error_code e; e.clear();])
@@ -565,7 +1146,7 @@ AC_DEFUN([BOOST_SYSTEM],
 # ------------------------------
 # Look for Boost.Test.  For the documentation of PREFERRED-RT-OPT, see the
 # documentation of BOOST_FIND_LIB above.
-AC_DEFUN([BOOST_TEST],
+BOOST_DEFUN([Test],
 [m4_pattern_allow([^BOOST_CHECK$])dnl
 BOOST_FIND_LIB([unit_test_framework], [$1],
                [boost/test/unit_test.hpp], [BOOST_CHECK(2 == 2);],
@@ -575,45 +1156,67 @@ BOOST_FIND_LIB([unit_test_framework], [$1],
 ])# BOOST_TEST
 
 
-# BOOST_THREADS([PREFERRED-RT-OPT])
+# BOOST_THREAD([PREFERRED-RT-OPT])
 # ---------------------------------
 # Look for Boost.Thread.  For the documentation of PREFERRED-RT-OPT, see the
 # documentation of BOOST_FIND_LIB above.
-# FIXME: Provide an alias "BOOST_THREAD".
-AC_DEFUN([BOOST_THREADS],
+BOOST_DEFUN([Thread],
 [dnl Having the pthread flag is required at least on GCC3 where
 dnl boost/thread.hpp would complain if we try to compile without
 dnl -pthread on GNU/Linux.
 AC_REQUIRE([_BOOST_PTHREAD_FLAG])dnl
-boost_threads_save_LIBS=$LIBS
-boost_threads_save_CPPFLAGS=$CPPFLAGS
-LIBS="$LIBS $boost_cv_pthread_flag"
-# Yes, we *need* to put the -pthread thing in CPPFLAGS because with GCC3,
-# boost/thread.hpp will trigger a #error if -pthread isn't used:
-#   boost/config/requires_threads.hpp:47:5: #error "Compiler threading support
-#   is not turned on. Please set the correct command line options for
-#   threading: -pthread (Linux), -pthreads (Solaris) or -mthreads (Mingw32)"
+boost_thread_save_LIBS=$LIBS
+boost_thread_save_LDFLAGS=$LDFLAGS
+boost_thread_save_CPPFLAGS=$CPPFLAGS
+# Link-time dependency from thread to system was added as of 1.49.0.
+if test $boost_major_version -ge 149; then
+BOOST_SYSTEM([$1])
+fi # end of the Boost.System check.
+m4_pattern_allow([^BOOST_SYSTEM_(LIBS|LDFLAGS)$])dnl
+LIBS="$LIBS $BOOST_SYSTEM_LIBS $boost_cv_pthread_flag"
+LDFLAGS="$LDFLAGS $BOOST_SYSTEM_LDFLAGS"
 CPPFLAGS="$CPPFLAGS $boost_cv_pthread_flag"
-BOOST_FIND_LIB([thread], [$1],
+
+# When compiling for the Windows platform, the threads library is named
+# differently.  This suffix doesn't exist in new versions of Boost, or
+# possibly new versions of GCC on mingw I am assuming it's Boost's change for
+# now and I am setting version to 1.48, for lack of knowledge as to when this
+# change occurred.
+if test $boost_major_version -lt 148; then
+  case $host_os in
+    (*mingw*) boost_thread_lib_ext=_win32;;
+  esac
+fi
+BOOST_FIND_LIBS([thread], [thread$boost_thread_lib_ext],
+                [$1],
                 [boost/thread.hpp], [boost::thread t; boost::mutex m;])
-BOOST_THREAD_LIBS="$BOOST_THREAD_LIBS $boost_cv_pthread_flag"
+
+case $host_os in
+  (*mingw*) boost_thread_w32_socket_link=-lws2_32;;
+esac
+
+BOOST_THREAD_LIBS="$BOOST_THREAD_LIBS $BOOST_SYSTEM_LIBS $boost_cv_pthread_flag $boost_thread_w32_socket_link"
+BOOST_THREAD_LDFLAGS="$BOOST_SYSTEM_LDFLAGS"
 BOOST_CPPFLAGS="$BOOST_CPPFLAGS $boost_cv_pthread_flag"
-LIBS=$boost_threads_save_LIBS
-CPPFLAGS=$boost_threads_save_CPPFLAGS
-])# BOOST_THREADS
+LIBS=$boost_thread_save_LIBS
+LDFLAGS=$boost_thread_save_LDFLAGS
+CPPFLAGS=$boost_thread_save_CPPFLAGS
+])# BOOST_THREAD
+
+AU_ALIAS([BOOST_THREADS], [BOOST_THREAD])
 
 
 # BOOST_TOKENIZER()
 # -----------------
 # Look for Boost.Tokenizer
-AC_DEFUN([BOOST_TOKENIZER],
+BOOST_DEFUN([Tokenizer],
 [BOOST_FIND_HEADER([boost/tokenizer.hpp])])
 
 
 # BOOST_TRIBOOL()
 # ---------------
 # Look for Boost.Tribool
-AC_DEFUN([BOOST_TRIBOOL],
+BOOST_DEFUN([Tribool],
 [BOOST_FIND_HEADER([boost/logic/tribool_fwd.hpp])
 BOOST_FIND_HEADER([boost/logic/tribool.hpp])
 ])
@@ -622,41 +1225,61 @@ BOOST_FIND_HEADER([boost/logic/tribool.hpp])
 # BOOST_TUPLE()
 # -------------
 # Look for Boost.Tuple
-AC_DEFUN([BOOST_TUPLE],
+BOOST_DEFUN([Tuple],
 [BOOST_FIND_HEADER([boost/tuple/tuple.hpp])])
 
 
+# BOOST_TYPETRAITS()
+# --------------------
+# Look for Boost.TypeTraits
+BOOST_DEFUN([TypeTraits],
+[BOOST_FIND_HEADER([boost/type_traits.hpp])])
+
+
 # BOOST_UTILITY()
 # ---------------
 # Look for Boost.Utility (noncopyable, result_of, base-from-member idiom,
 # etc.)
-AC_DEFUN([BOOST_UTILITY],
+BOOST_DEFUN([Utility],
 [BOOST_FIND_HEADER([boost/utility.hpp])])
 
 
 # BOOST_VARIANT()
 # ---------------
 # Look for Boost.Variant.
-AC_DEFUN([BOOST_VARIANT],
+BOOST_DEFUN([Variant],
 [BOOST_FIND_HEADER([boost/variant/variant_fwd.hpp])
 BOOST_FIND_HEADER([boost/variant.hpp])])
 
 
+# BOOST_POINTER_CONTAINER()
+# ------------------------
+# Look for Boost.PointerContainer
+BOOST_DEFUN([Pointer_Container],
+[BOOST_FIND_HEADER([boost/ptr_container/ptr_deque.hpp])
+BOOST_FIND_HEADER([boost/ptr_container/ptr_list.hpp])
+BOOST_FIND_HEADER([boost/ptr_container/ptr_vector.hpp])
+BOOST_FIND_HEADER([boost/ptr_container/ptr_array.hpp])
+BOOST_FIND_HEADER([boost/ptr_container/ptr_set.hpp])
+BOOST_FIND_HEADER([boost/ptr_container/ptr_map.hpp])
+])# BOOST_POINTER_CONTAINER
+
+
 # BOOST_WAVE([PREFERRED-RT-OPT])
 # ------------------------------
 # NOTE: If you intend to use Wave/Spirit with thread support, make sure you
-# call BOOST_THREADS first.
+# call BOOST_THREAD first.
 # Look for Boost.Wave.  For the documentation of PREFERRED-RT-OPT, see the
 # documentation of BOOST_FIND_LIB above.
-AC_DEFUN([BOOST_WAVE],
+BOOST_DEFUN([Wave],
 [AC_REQUIRE([BOOST_FILESYSTEM])dnl
 AC_REQUIRE([BOOST_DATE_TIME])dnl
 boost_wave_save_LIBS=$LIBS
 boost_wave_save_LDFLAGS=$LDFLAGS
 m4_pattern_allow([^BOOST_((FILE)?SYSTEM|DATE_TIME|THREAD)_(LIBS|LDFLAGS)$])dnl
-LIBS="$LIBS $BOOST_SYSTEM_LIBS $BOOST_FILESYSTEM_LIBS $BOOST_DATE_TIME_LIBS\
+LIBS="$LIBS $BOOST_SYSTEM_LIBS $BOOST_FILESYSTEM_LIBS $BOOST_DATE_TIME_LIBS \
 $BOOST_THREAD_LIBS"
-LDFLAGS="$LDFLAGS $BOOST_SYSTEM_LDFLAGS $BOOST_FILESYSTEM_LDFLAGS\
+LDFLAGS="$LDFLAGS $BOOST_SYSTEM_LDFLAGS $BOOST_FILESYSTEM_LDFLAGS \
 $BOOST_DATE_TIME_LDFLAGS $BOOST_THREAD_LDFLAGS"
 BOOST_FIND_LIB([wave], [$1],
                 [boost/wave.hpp],
@@ -669,7 +1292,7 @@ LDFLAGS=$boost_wave_save_LDFLAGS
 # BOOST_XPRESSIVE()
 # -----------------
 # Look for Boost.Xpressive (new since 1.36.0).
-AC_DEFUN([BOOST_XPRESSIVE],
+BOOST_DEFUN([Xpressive],
 [BOOST_FIND_HEADER([boost/xpressive/xpressive.hpp])])
 
 
@@ -680,8 +1303,16 @@ AC_DEFUN([BOOST_XPRESSIVE],
 
 # _BOOST_PTHREAD_FLAG()
 # ---------------------
-# Internal helper for BOOST_THREADS.  Based on ACX_PTHREAD:
-# http://autoconf-archive.cryp.to/acx_pthread.html
+# Internal helper for BOOST_THREAD.  Computes boost_cv_pthread_flag
+# which must be used in CPPFLAGS and LIBS.
+#
+# Yes, we *need* to put the -pthread thing in CPPFLAGS because with GCC3,
+# boost/thread.hpp will trigger a #error if -pthread isn't used:
+#   boost/config/requires_threads.hpp:47:5: #error "Compiler threading support
+#   is not turned on. Please set the correct command line options for
+#   threading: -pthread (Linux), -pthreads (Solaris) or -mthreads (Mingw32)"
+#
+# Based on ACX_PTHREAD: http://autoconf-archive.cryp.to/acx_pthread.html
 AC_DEFUN([_BOOST_PTHREAD_FLAG],
 [AC_REQUIRE([AC_PROG_CXX])dnl
 AC_REQUIRE([AC_CANONICAL_HOST])dnl
@@ -749,6 +1380,14 @@ AC_LANG_POP([C++])dnl
 m4_define([_BOOST_gcc_test],
 ["defined __GNUC__ && __GNUC__ == $1 && __GNUC_MINOR__ == $2 && !defined __ICC @ gcc$1$2"])dnl
 
+# _BOOST_mingw_test(MAJOR, MINOR)
+# -----------------------------
+# Internal helper for _BOOST_FIND_COMPILER_TAG.
+m4_define([_BOOST_mingw_test],
+["defined __GNUC__ && __GNUC__ == $1 && __GNUC_MINOR__ == $2 && !defined __ICC && \
+  (defined WIN32 || defined WINNT || defined _WIN32 || defined __WIN32 \
+         || defined __WIN32__ || defined __WINNT || defined __WINNT__) @ mgw$1$2"])dnl
+
 
 # _BOOST_FIND_COMPILER_TAG()
 # --------------------------
@@ -757,9 +1396,12 @@ m4_define([_BOOST_gcc_test],
 # build.  The Boost build system seems to call this a `tag'.
 AC_DEFUN([_BOOST_FIND_COMPILER_TAG],
 [AC_REQUIRE([AC_PROG_CXX])dnl
-AC_CACHE_CHECK([for the toolset name used by Boost for $CXX], [boost_cv_lib_tag],
-[AC_LANG_PUSH([C++])dnl
-  boost_cv_lib_tag=unknown
+AC_REQUIRE([AC_CANONICAL_HOST])dnl
+AC_CACHE_CHECK([for the toolset name used by Boost for $CXX],
+               [boost_cv_lib_tag],
+[boost_cv_lib_tag=unknown
+if test x$boost_cv_inc_path != xno; then
+  AC_LANG_PUSH([C++])dnl
   # The following tests are mostly inspired by boost/config/auto_link.hpp
   # The list is sorted to most recent/common to oldest compiler (in order
   # to increase the likelihood of finding the right compiler with the
@@ -773,18 +1415,50 @@ AC_CACHE_CHECK([for the toolset name used by Boost for $CXX], [boost_cv_lib_tag]
   #   como, edg, kcc, bck, mp, sw, tru, xlc
   # I'm not sure about my test for `il' (be careful: Intel's ICC pre-defines
   # the same defines as GCC's).
-  # TODO: Move the test on GCC 4.4 up once it's released.
   for i in \
+    _BOOST_mingw_test(6, 2) \
+    _BOOST_gcc_test(6, 2) \
+    _BOOST_mingw_test(6, 1) \
+    _BOOST_gcc_test(6, 1) \
+    _BOOST_mingw_test(6, 0) \
+    _BOOST_gcc_test(6, 0) \
+    _BOOST_mingw_test(5, 3) \
+    _BOOST_gcc_test(5, 3) \
+    _BOOST_mingw_test(5, 2) \
+    _BOOST_gcc_test(5, 2) \
+    _BOOST_mingw_test(5, 1) \
+    _BOOST_gcc_test(5, 1) \
+    _BOOST_mingw_test(5, 0) \
+    _BOOST_gcc_test(5, 0) \
+    _BOOST_mingw_test(4, 10) \
+    _BOOST_gcc_test(4, 10) \
+    _BOOST_mingw_test(4, 9) \
+    _BOOST_gcc_test(4, 9) \
+    _BOOST_mingw_test(4, 8) \
+    _BOOST_gcc_test(4, 8) \
+    _BOOST_mingw_test(4, 7) \
+    _BOOST_gcc_test(4, 7) \
+    _BOOST_mingw_test(4, 6) \
+    _BOOST_gcc_test(4, 6) \
+    _BOOST_mingw_test(4, 5) \
+    _BOOST_gcc_test(4, 5) \
+    _BOOST_mingw_test(4, 4) \
+    _BOOST_gcc_test(4, 4) \
+    _BOOST_mingw_test(4, 3) \
     _BOOST_gcc_test(4, 3) \
+    _BOOST_mingw_test(4, 2) \
     _BOOST_gcc_test(4, 2) \
+    _BOOST_mingw_test(4, 1) \
     _BOOST_gcc_test(4, 1) \
+    _BOOST_mingw_test(4, 0) \
     _BOOST_gcc_test(4, 0) \
     "defined __GNUC__ && __GNUC__ == 3 && !defined __ICC \
      && (defined WIN32 || defined WINNT || defined _WIN32 || defined __WIN32 \
          || defined __WIN32__ || defined __WINNT || defined __WINNT__) @ mgw" \
     _BOOST_gcc_test(3, 4) \
     _BOOST_gcc_test(3, 3) \
-    "defined _MSC_VER && _MSC_VER >= 1400 @ vc80" \
+    "defined _MSC_VER && _MSC_VER >= 1500 @ vc90" \
+    "defined _MSC_VER && _MSC_VER == 1400 @ vc80" \
     _BOOST_gcc_test(3, 2) \
     "defined _MSC_VER && _MSC_VER == 1310 @ vc71" \
     _BOOST_gcc_test(3, 1) \
@@ -793,7 +1467,6 @@ AC_CACHE_CHECK([for the toolset name used by Boost for $CXX], [boost_cv_lib_tag]
     "defined __ICC && (defined __unix || defined __unix__) @ il" \
     "defined __ICL @ iw" \
     "defined _MSC_VER && _MSC_VER == 1300 @ vc7" \
-    _BOOST_gcc_test(4, 4) \
     _BOOST_gcc_test(2, 95) \
     "defined __MWERKS__ && __MWERKS__ <= 0x32FF @ cw9" \
     "defined _MSC_VER && _MSC_VER < 1300 && !defined UNDER_CE @ vc6" \
@@ -816,16 +1489,24 @@ AC_LANG_POP([C++])dnl
     # to "gcc41" for instance.
     *-gcc | *'-gcc ') :;; #(  Don't re-add -gcc: it's already in there.
     gcc*)
+      boost_tag_x=
+      case $host_os in #(
+        darwin*)
+          if test $boost_major_version -ge 136; then
+            # The `x' added in r46793 of Boost.
+            boost_tag_x=x
+          fi;;
+      esac
       # We can specify multiple tags in this variable because it's used by
       # BOOST_FIND_LIB that does a `for tag in -$boost_cv_lib_tag' ...
-      boost_cv_lib_tag="$boost_cv_lib_tag -gcc"
+      boost_cv_lib_tag="$boost_tag_x$boost_cv_lib_tag -${boost_tag_x}gcc"
       ;; #(
     unknown)
       AC_MSG_WARN([[could not figure out which toolset name to use for $CXX]])
       boost_cv_lib_tag=
       ;;
   esac
-])dnl end of AC_CACHE_CHECK
+fi])dnl end of AC_CACHE_CHECK
 ])# _BOOST_FIND_COMPILER_TAG
 
 
@@ -835,6 +1516,7 @@ AC_LANG_POP([C++])dnl
 # Thread) flavors of Boost.  Sets boost_guess_use_mt accordingly.
 AC_DEFUN([_BOOST_GUESS_WHETHER_TO_USE_MT],
 [# Check whether we do better use `mt' even though we weren't ask to.
+AC_LANG_PUSH([C++])dnl
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #if defined _REENTRANT || defined _MT || defined __MT__
 /* use -mt */
@@ -842,6 +1524,7 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 # error MT not needed
 #endif
 ]])], [boost_guess_use_mt=:], [boost_guess_use_mt=false])
+AC_LANG_POP([C++])dnl
 ])
 
 # _BOOST_AC_LINK_IFELSE(PROGRAM, [ACTION-IF-TRUE], [ACTION-IF-FALSE])
@@ -851,22 +1534,25 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 # rm -f conftest.$ac_objext in between to really different tests, otherwise
 # you will try to link a conftest.o left behind by a previous test.
 # Used to aggressively optimize BOOST_FIND_LIB (see the big comment in this
-# macro)
+# macro).
+#
+# Don't use "break" in the actions, as it would short-circuit some code
+# this macro runs after the actions.
 m4_define([_BOOST_AC_LINK_IFELSE],
 [m4_ifvaln([$1], [AC_LANG_CONFTEST([$1])])dnl
 rm -f conftest$ac_exeext
-boost_ac_ext_save=$ac_ext
+boost_save_ac_ext=$ac_ext
 boost_use_source=:
 # If we already have a .o, re-use it.  We change $ac_ext so that $ac_link
 # tries to link the existing object file instead of compiling from source.
 test -f conftest.$ac_objext && ac_ext=$ac_objext && boost_use_source=false &&
   _AS_ECHO_LOG([re-using the existing conftest.$ac_objext])
 AS_IF([_AC_DO_STDERR($ac_link) && {
-	 test -z "$ac_[]_AC_LANG_ABBREV[]_werror_flag" ||
-	 test ! -s conftest.err
+         test -z "$ac_[]_AC_LANG_ABBREV[]_werror_flag" ||
+         test ! -s conftest.err
        } && test -s conftest$ac_exeext && {
-	 test "$cross_compiling" = yes ||
-	 $as_executable_p conftest$ac_exeext
+         test "$cross_compiling" = yes ||
+         $as_executable_p conftest$ac_exeext
 dnl FIXME: use AS_TEST_X instead when 2.61 is widespread enough.
        }],
       [$2],
@@ -874,6 +1560,8 @@ dnl FIXME: use AS_TEST_X instead when 2.61 is widespread enough.
          _AC_MSG_LOG_CONFTEST
        fi
        $3])
+ac_objext=$boost_save_ac_objext
+ac_ext=$boost_save_ac_ext
 dnl Delete also the IPA/IPO (Inter Procedural Analysis/Optimization)
 dnl information created by the PGI compiler (conftest_ipa8_conftest.oo),
 dnl as it would interfere with the next link command.