diff --git a/.travis.yml b/.travis.yml
index da64807c..5b38f3bc 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,8 @@ language: cpp
 
 sudo: false
 
+dist : xenial
+
 branches:
   only:
     - master
@@ -26,6 +28,7 @@ matrix:
       env: TOOLSET=gcc COMPILER=g++ CXXSTD=03,11
 
     - os: linux
+      dist: trusty
       compiler: g++-4.4
       env: TOOLSET=gcc COMPILER=g++-4.4 CXXSTD=98,0x
       addons:
@@ -36,6 +39,7 @@ matrix:
             - ubuntu-toolchain-r-test
 
     - os: linux
+      dist: trusty
       compiler: g++-4.6
       env: TOOLSET=gcc COMPILER=g++-4.6 CXXSTD=03,0x
       addons:
@@ -46,6 +50,7 @@ matrix:
             - ubuntu-toolchain-r-test
 
     - os: linux
+      dist: trusty
       env: TOOLSET=gcc COMPILER=g++-4.7 CXXSTD=03,11
       addons:
         apt:
@@ -55,6 +60,7 @@ matrix:
             - ubuntu-toolchain-r-test
 
     - os: linux
+      dist: trusty
       env: TOOLSET=gcc COMPILER=g++-4.8 CXXSTD=03,11
       addons:
         apt:
@@ -64,6 +70,7 @@ matrix:
             - ubuntu-toolchain-r-test
 
     - os: linux
+      dist: trusty
       env: TOOLSET=gcc COMPILER=g++-4.9 CXXSTD=03,11
       addons:
         apt:
@@ -117,10 +124,22 @@ matrix:
           sources:
             - ubuntu-toolchain-r-test
 
+    - os: linux
+      dist: trusty
+      compiler: g++-9
+      env: TOOLSET=gcc COMPILER=g++-9 CXXSTD=03,11,14,17,2a
+      addons:
+        apt:
+          packages:
+            - g++-9
+          sources:
+            - ubuntu-toolchain-r-test
+
     - os: linux
       env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11
 
     - os: linux
+      dist: trusty
       env: TOOLSET=clang COMPILER=clang++-3.5 CXXSTD=03,11,14,1z
       addons:
         apt:
@@ -131,6 +150,7 @@ matrix:
             - llvm-toolchain-precise-3.5
 
     - os: linux
+      dist: trusty
       env: TOOLSET=clang COMPILER=clang++-3.6 CXXSTD=03,11,14,1z
       addons:
         apt:
@@ -141,6 +161,7 @@ matrix:
             - llvm-toolchain-precise-3.6
 
     - os: linux
+      dist: trusty
       env: TOOLSET=clang COMPILER=clang++-3.7 CXXSTD=03,11,14,1z
       addons:
         apt:
@@ -151,6 +172,7 @@ matrix:
             - llvm-toolchain-precise-3.7
 
     - os: linux
+      dist: trusty
       env: TOOLSET=clang COMPILER=clang++-3.8 CXXSTD=03,11,14,1z
       addons:
         apt:
@@ -161,6 +183,7 @@ matrix:
             - llvm-toolchain-precise-3.8
 
     - os: linux
+      dist: trusty
       env: TOOLSET=clang COMPILER=clang++-3.9 CXXSTD=03,11,14,1z
       addons:
         apt:
@@ -179,7 +202,7 @@ matrix:
             - clang-4.0
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-4.0
+            - llvm-toolchain-xenial-4.0
 
     - os: linux
       compiler: clang++-5.0
@@ -190,11 +213,11 @@ matrix:
             - clang-5.0
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-5.0
+            - llvm-toolchain-xenial-5.0
 
     - os: linux
       compiler: clang++-libc++
-      env: TOOLSET=clang COMPILER=clang++-libc++ CXXSTD=03,11,14,1z
+      env: TOOLSET=clang COMPILER="clang++-5.0 -stdlib=libc++" CXXSTD=03,11,14
       addons:
         apt:
           packages:
@@ -202,7 +225,7 @@ matrix:
             - clang-5.0
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-5.0
+            - llvm-toolchain-xenial-5.0
 
     - os: linux
       compiler: clang++-6.0
@@ -213,7 +236,7 @@ matrix:
             - clang-6.0
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-6.0
+            - llvm-toolchain-xenial-6.0
 
     - os: linux
       compiler: clang++-libc++
@@ -225,11 +248,37 @@ matrix:
             - libc++-dev
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-6.0
+            - llvm-toolchain-xenial-6.0
+
+    - os: linux
+      compiler: clang++-7
+      env: TOOLSET=clang COMPILER=clang++-7 CXXSTD=03,11,14,1z
+      addons:
+        apt:
+          packages:
+            - clang-7
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-xenial-7
+
+    - os: linux
+      compiler: clang++-8
+      env: TOOLSET=clang COMPILER=clang++-8 CXXSTD=03,11,14,17,2a
+      addons:
+        apt:
+          packages:
+            - clang-8
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-xenial-8
+
+    - os: osx
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,17,2a
+      osx_image: xcode10.2
 
     - os: osx
       env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
-      osx_image: xcode9.1
+      osx_image: xcode9.4
 
     - os: osx
       env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
@@ -271,9 +320,7 @@ script:
   - if [ $TEST_INTEL ]; then source ~/.bashrc; fi
   - |-
     echo "using $TOOLSET : : $COMPILER : <cxxflags>$EXTRA_FLAGS <linkflags>$EXTRA_FLAGS ;" > ~/user-config.jam
-  - IFS=','
-  - for CXXLOCAL in $CXXSTD; do  (cd libs/config/test && ../../../b2 config_info_travis_install toolset=$TOOLSET cxxstd=$CXXLOCAL $CXXSTD_DIALECT && echo With Standard Version $CXXLOCAL && ./config_info_travis && rm ./config_info_travis)  done
-  - unset IFS
+  - ./b2 libs/config/test//print_config_info toolset=$TOOLSET cxxstd=$CXXSTD $CXXSTD_DIALECT
   - ./b2 -j3 libs/config/test toolset=$TOOLSET cxxstd=$CXXSTD $CXXSTD_DIALECT
 
 notifications:
diff --git a/appveyor.bat b/appveyor.bat
deleted file mode 100644
index fb6d5279..00000000
--- a/appveyor.bat
+++ /dev/null
@@ -1,12 +0,0 @@
-IF NOT DEFINED CXXSTD (
-ECHO %ARGS:"=%
-..\..\..\b2 config_info_travis_install %ARGS:"=%
-config_info_travis
-del config_info_travis.exe
-)
-IF DEFINED CXXSTD FOR %%A IN (%CXXSTD%) DO (
-ECHO %ARGS:"=%
-..\..\..\b2 -a -d2 config_info_travis_install %ARGS:"=% cxxstd=%%A
-config_info_travis
-del config_info_travis.exe
-)
\ No newline at end of file
diff --git a/appveyor.yml b/appveyor.yml
index a6fdbc9c..445ac97e 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -22,6 +22,10 @@ environment:
       ARGS: --toolset=msvc-14.1 address-model=32
     - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
       ARGS: --toolset=msvc-14.1 address-model=64 cxxflags=-std:c++latest cxxflags=-permissive-
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+      ARGS: --toolset=clang-win address-model=64
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+      ARGS: --toolset=clang-win address-model=32
     - ARGS: --toolset=msvc-9.0  address-model=32
     - ARGS: --toolset=msvc-10.0 address-model=32
     - ARGS: --toolset=msvc-11.0 address-model=32
@@ -65,5 +69,5 @@ build: off
 
 test_script:
   - cd libs\config\test
-  - ..\appveyor.bat
+  - ..\..\..\b2 print_config_info %ARGS% cxxstd=%CXXSTD%
   - ..\..\..\b2 -j3 %ARGS% cxxstd=%CXXSTD%
diff --git a/checks/architecture/Jamroot.jam b/checks/architecture/Jamroot.jam
index 03f59534..0d3b5e7b 100644
--- a/checks/architecture/Jamroot.jam
+++ b/checks/architecture/Jamroot.jam
@@ -22,3 +22,4 @@ obj power    : power.cpp ;
 obj riscv    : riscv.cpp ;
 obj sparc    : sparc.cpp ;
 obj x86      : x86.cpp ;
+obj s390x    : s390x.cpp ;
diff --git a/checks/architecture/s390x.cpp b/checks/architecture/s390x.cpp
new file mode 100644
index 00000000..a3630706
--- /dev/null
+++ b/checks/architecture/s390x.cpp
@@ -0,0 +1,11 @@
+// s390x.cpp
+//
+// Copyright (c) 2012 Steven Watanabe
+//
+// Distributed under the Boost Software License Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#if !defined(__s390x__)
+#error "Not S390x"
+#endif
diff --git a/include/boost/config/auto_link.hpp b/include/boost/config/auto_link.hpp
index d0079d9b..e74f3c10 100644
--- a/include/boost/config/auto_link.hpp
+++ b/include/boost/config/auto_link.hpp
@@ -99,7 +99,8 @@ BOOST_LIB_VERSION:    The Boost version, in the form x_y, for Boost version x.y.
 #if defined(BOOST_MSVC) \
     || defined(__BORLANDC__) \
     || (defined(__MWERKS__) && defined(_WIN32) && (__MWERKS__ >= 0x3000)) \
-    || (defined(__ICL) && defined(_MSC_EXTENSIONS) && (_MSC_VER >= 1200))
+    || (defined(__ICL) && defined(_MSC_EXTENSIONS) && (_MSC_VER >= 1200)) \
+    || (defined(BOOST_CLANG) && defined(BOOST_WINDOWS) && defined(_MSC_VER) && (__clang_major__ >= 4))
 
 #ifndef BOOST_VERSION_HPP
 #  include <boost/version.hpp>
@@ -203,6 +204,11 @@ BOOST_LIB_VERSION:    The Boost version, in the form x_y, for Boost version x.y.
      // Metrowerks CodeWarrior 9.x
 #    define BOOST_LIB_TOOLSET "cw9"
 
+#  elif defined(BOOST_CLANG) && defined(BOOST_WINDOWS) && defined(_MSC_VER) && (__clang_major__ >= 4)
+
+     // Clang on Windows
+#    define BOOST_LIB_TOOLSET "clangw" BOOST_STRINGIZE(__clang_major__)
+
 #  endif
 #endif // BOOST_LIB_TOOLSET
 
diff --git a/include/boost/config/detail/suffix.hpp b/include/boost/config/detail/suffix.hpp
index 2550239c..86f6081e 100644
--- a/include/boost/config/detail/suffix.hpp
+++ b/include/boost/config/detail/suffix.hpp
@@ -999,7 +999,7 @@ namespace std{ using ::type_info; }
 #if __has_cpp_attribute(nodiscard)
 # define BOOST_ATTRIBUTE_NODISCARD [[nodiscard]]
 #endif
-#if __has_cpp_attribute(no_unique_address)
+#if __has_cpp_attribute(no_unique_address) && !(defined(__GNUC__) && (__cplusplus < 201100))
 # define BOOST_ATTRIBUTE_NO_UNIQUE_ADDRESS [[no_unique_address]]
 #endif
 #endif
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 41aadf1b..cfc42ade 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -8,6 +8,7 @@
 # the template defined in options_v2.jam.
 #
 
+import feature ;
 import testing ;
 
 project
@@ -114,7 +115,26 @@ obj has_clang_implicit_fallthrough : cmd_line_check.cpp :
 
 explicit has_clang_implicit_fallthrough ;
 
+exe config_info_printer : config_info.cpp ;
+explicit config_info_printer ;
+
+actions print-run
+{
+      echo With Standard Version $(STANDARD:E=default)
+      echo =====================================================================
+      $(>)
+}
+
+rule print-run ( target : sources * : properties * )
+{
+    STANDARD on $(target) = [ feature.get-values <cxxstd> : $(properties) ] ;
+}
+
+notfile print_config_info : @print-run : config_info_printer ;
+explicit print_config_info ;
+
+# Backwards compatibility:
 exe config_info_travis : config_info.cpp ;
 install config_info_travis_install : config_info_travis : <location>. ;
 explicit config_info_travis_install ;
-explicit config_info_travis ;
+
diff --git a/test/boost_no_cxx11_hdr_atomic.ipp b/test/boost_no_cxx11_hdr_atomic.ipp
index 171dcc3d..ceabb650 100644
--- a/test/boost_no_cxx11_hdr_atomic.ipp
+++ b/test/boost_no_cxx11_hdr_atomic.ipp
@@ -21,72 +21,78 @@
 
 namespace boost_no_cxx11_hdr_atomic {
 
-int test()
-{
-   std::memory_order m = static_cast<std::memory_order>(std::memory_order_relaxed | std::memory_order_consume | std::memory_order_acquire | std::memory_order_release 
-                           | std::memory_order_acq_rel | std::memory_order_seq_cst);
-   (void)m;
+   void consume(std::memory_order)
+   {}
 
-   std::atomic<int> a1;
-   std::atomic<unsigned> a2;
-   std::atomic<int*>    a3;
-   a1.is_lock_free();
-   a1.store(1);
-   a1.load();
-   a1.exchange(2);
-   int v;
-   a1.compare_exchange_weak(v, 2, std::memory_order_relaxed, std::memory_order_relaxed);
-   a1.compare_exchange_strong(v, 2, std::memory_order_relaxed, std::memory_order_relaxed);
-   a1.fetch_add(2);
-   a1.fetch_sub(3);
-   a1.fetch_and(3);
-   a1.fetch_or(1);
-   a1.fetch_xor(1);
-   a1++;
-   ++a1;
-   a1--;
-   --a1;
-   a1 += 2;
-   a1 -= 2;
-   a1 &= 1;
-   a1 |= 2;
-   a1 ^= 3;
+   int test()
+   {
+      consume(std::memory_order_relaxed);
+      consume(std::memory_order_consume);
+      consume(std::memory_order_acquire);
+      consume(std::memory_order_release);
+      consume(std::memory_order_acq_rel);
+      consume(std::memory_order_seq_cst);
 
-   a2 = 0u;
+      std::atomic<int> a1;
+      std::atomic<unsigned> a2;
+      std::atomic<int*>    a3;
+      a1.is_lock_free();
+      a1.store(1);
+      a1.load();
+      a1.exchange(2);
+      int v;
+      a1.compare_exchange_weak(v, 2, std::memory_order_relaxed, std::memory_order_relaxed);
+      a1.compare_exchange_strong(v, 2, std::memory_order_relaxed, std::memory_order_relaxed);
+      a1.fetch_add(2);
+      a1.fetch_sub(3);
+      a1.fetch_and(3);
+      a1.fetch_or(1);
+      a1.fetch_xor(1);
+      a1++;
+      ++a1;
+      a1--;
+      --a1;
+      a1 += 2;
+      a1 -= 2;
+      a1 &= 1;
+      a1 |= 2;
+      a1 ^= 3;
 
-   a3.store(&v);
-   a3.fetch_add(1);
-   a3.fetch_sub(1);
-   ++a3;
-   --a3;
-   a3++;
-   a3--;
-   a3 += 1;
-   a3 -= 1;
+      a2 = 0u;
 
-   std::atomic_is_lock_free(&a1);
-   // This produces linker errors on Mingw32 for some reason, probably not required anyway for most uses??
-   //std::atomic_init(&a1, 2);
-   std::atomic_store(&a1, 3);
-   std::atomic_store_explicit(&a1, 3, std::memory_order_relaxed);
-   std::atomic_load(&a1);
-   std::atomic_load_explicit(&a1, std::memory_order_relaxed);
-   std::atomic_exchange(&a1, 3);
-   std::atomic_compare_exchange_weak(&a1, &v, 2);
-   std::atomic_compare_exchange_strong(&a1, &v, 2);
-   std::atomic_compare_exchange_weak_explicit(&a1, &v, 2, std::memory_order_relaxed, std::memory_order_relaxed);
-   std::atomic_compare_exchange_strong_explicit(&a1, &v, 2, std::memory_order_relaxed, std::memory_order_relaxed);
+      a3.store(&v);
+      a3.fetch_add(1);
+      a3.fetch_sub(1);
+      ++a3;
+      --a3;
+      a3++;
+      a3--;
+      a3 += 1;
+      a3 -= 1;
 
-   std::atomic_flag f = ATOMIC_FLAG_INIT;
-   f.test_and_set(std::memory_order_relaxed);
-   f.test_and_set();
-   f.clear(std::memory_order_relaxed);
-   f.clear();
+      std::atomic_is_lock_free(&a1);
+      // This produces linker errors on Mingw32 for some reason, probably not required anyway for most uses??
+      //std::atomic_init(&a1, 2);
+      std::atomic_store(&a1, 3);
+      std::atomic_store_explicit(&a1, 3, std::memory_order_relaxed);
+      std::atomic_load(&a1);
+      std::atomic_load_explicit(&a1, std::memory_order_relaxed);
+      std::atomic_exchange(&a1, 3);
+      std::atomic_compare_exchange_weak(&a1, &v, 2);
+      std::atomic_compare_exchange_strong(&a1, &v, 2);
+      std::atomic_compare_exchange_weak_explicit(&a1, &v, 2, std::memory_order_relaxed, std::memory_order_relaxed);
+      std::atomic_compare_exchange_strong_explicit(&a1, &v, 2, std::memory_order_relaxed, std::memory_order_relaxed);
 
-   std::atomic_thread_fence(std::memory_order_relaxed);
-   std::atomic_signal_fence(std::memory_order_relaxed);
+      std::atomic_flag f = ATOMIC_FLAG_INIT;
+      f.test_and_set(std::memory_order_relaxed);
+      f.test_and_set();
+      f.clear(std::memory_order_relaxed);
+      f.clear();
 
-   return 0;
-}
+      std::atomic_thread_fence(std::memory_order_relaxed);
+      std::atomic_signal_fence(std::memory_order_relaxed);
+
+      return 0;
+   }
 
 }
diff --git a/test/boost_no_unicode_literals.ipp b/test/boost_no_unicode_literals.ipp
index bbf865ec..0faf9b7d 100644
--- a/test/boost_no_unicode_literals.ipp
+++ b/test/boost_no_unicode_literals.ipp
@@ -17,7 +17,7 @@ void quiet_warning(const CharT*){}
 
 int test()
 {
-#ifdef _­_­cpp_­char8_­t
+#if defined(__cpp_char8_type) || defined(__cpp_char8_t)
    // The change to char8_t in C++20 is a breaking change to the std:
    const char8_t* c8 = u8"";
 #else
diff --git a/test/config_info.cpp b/test/config_info.cpp
index bb3ef249..f5ec470d 100644
--- a/test/config_info.cpp
+++ b/test/config_info.cpp
@@ -1231,25 +1231,6 @@ void print_boost_macros()
    PRINT_MACRO(BOOST_NO_USING_TEMPLATE);
    PRINT_MACRO(BOOST_NO_VOID_RETURNS);
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
    // END GENERATED BLOCK
 
    PRINT_MACRO(BOOST_INTEL);
@@ -1267,12 +1248,26 @@ void print_boost_macros()
    PRINT_MACRO(BOOST_FALLTHROUGH);
    PRINT_MACRO(BOOST_MAY_ALIAS);
    PRINT_MACRO(BOOST_NO_MAY_ALIAS);
+   PRINT_MACRO(BOOST_ATTRIBUTE_NO_UNIQUE_ADDRESS);
+   PRINT_MACRO(BOOST_ATTRIBUTE_UNUSED);
+   PRINT_MACRO(BOOST_UNLIKELY);
+   PRINT_MACRO(BOOST_NORETURN);
 }
 
 void print_sd6_macros()
 {
     // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0096r5.html
 
+    // C++20:
+    PRINT_MACRO(__cpp_aggregate_paren_init);
+    PRINT_MACRO(__cpp_char8_t);
+    PRINT_MACRO(__cpp_char8_type);
+    PRINT_MACRO(__cpp_conditional_explicit);
+    PRINT_MACRO(__cpp_coroutines);
+    PRINT_MACRO(__cpp_impl_destroying_delete);
+    PRINT_MACRO(__cpp_impl_three_way_comparison);
+    PRINT_MACRO(__cpp_nontype_template_parameter_class);
+
     // C++17:
     PRINT_MACRO(__cpp_hex_float);
     PRINT_MACRO(__cpp_inline_variables);