diff --git a/.travis.yml b/.travis.yml
index d24ddab..317b657 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,5 @@
 # Copyright 2016, 2017 Peter Dimov
+# Copyright 2019 Andrey Semashev
 # Distributed under the Boost Software License, Version 1.0.
 # (See accompanying file LICENSE_1_0.txt or copy at http://boost.org/LICENSE_1_0.txt)
 
@@ -24,13 +25,66 @@ matrix:
     - env: BOGUS_JOB=true
 
   include:
+# gcc, Linux
     - os: linux
-      compiler: g++
-      env: TOOLSET=gcc CXXSTD=03,11
+      dist: trusty
+      compiler: gcc-4.4
+      env: TOOLSET=gcc COMPILER=g++-4.4 CXXSTD=98,0x
+      addons:
+        apt:
+          packages:
+            - g++-4.4
+          sources:
+            - ubuntu-toolchain-r-test
 
     - os: linux
-      compiler: g++-5
-      env: TOOLSET=gcc-5 CXXSTD=03,11,14,1z
+      dist: trusty
+      compiler: gcc-4.6
+      env: TOOLSET=gcc COMPILER=g++-4.6 CXXSTD=03,0x
+      addons:
+        apt:
+          packages:
+            - g++-4.6
+          sources:
+            - ubuntu-toolchain-r-test
+
+    - os: linux
+      dist: trusty
+      compiler: gcc-4.7
+      env: TOOLSET=gcc COMPILER=g++-4.7 CXXSTD=03,11
+      addons:
+        apt:
+          packages:
+            - g++-4.7
+          sources:
+            - ubuntu-toolchain-r-test
+
+    - os: linux
+      dist: xenial
+      compiler: gcc-4.8
+      env: TOOLSET=gcc COMPILER=g++-4.8 CXXSTD=03,11
+      addons:
+        apt:
+          packages:
+            - g++-4.8
+          sources:
+            - ubuntu-toolchain-r-test
+
+    - os: linux
+      dist: xenial
+      compiler: gcc-4.9
+      env: TOOLSET=gcc COMPILER=g++-4.9 CXXSTD=03,11
+      addons:
+        apt:
+          packages:
+            - g++-4.9
+          sources:
+            - ubuntu-toolchain-r-test
+
+    - os: linux
+      dist: xenial
+      compiler: gcc-5
+      env: TOOLSET=gcc COMPILER=g++-5 CXXSTD=03,11,14,1z
       addons:
         apt:
           packages:
@@ -39,8 +93,9 @@ matrix:
             - ubuntu-toolchain-r-test
 
     - os: linux
-      compiler: g++-6
-      env: TOOLSET=gcc-6 CXXSTD=03,11,14,1z
+      dist: xenial
+      compiler: gcc-6
+      env: TOOLSET=gcc COMPILER=g++-6 CXXSTD=03,11,14,1z
       addons:
         apt:
           packages:
@@ -49,8 +104,9 @@ matrix:
             - ubuntu-toolchain-r-test
 
     - os: linux
-      compiler: g++-7
-      env: TOOLSET=gcc-7 CXXSTD=03,11,14,17
+      dist: xenial
+      compiler: gcc-7
+      env: TOOLSET=gcc COMPILER=g++-7 CXXSTD=03,11,14,17
       addons:
         apt:
           packages:
@@ -59,12 +115,249 @@ matrix:
             - ubuntu-toolchain-r-test
 
     - os: linux
-      compiler: clang++
-      env: TOOLSET=clang CXXSTD=03,11,14,1z
+      dist: xenial
+      compiler: gcc-8
+      env: TOOLSET=gcc COMPILER=g++-8 CXXSTD=03,11,14,17,2a
+      addons:
+        apt:
+          packages:
+            - g++-8
+          sources:
+            - ubuntu-toolchain-r-test
+
+    - os: linux
+      dist: bionic
+      compiler: gcc-9
+      env: TOOLSET=gcc COMPILER=g++-9 CXXSTD=03,11,14,17,2a
+      addons:
+        apt:
+          packages:
+            - g++-9
+          sources:
+            - sourceline: "ppa:ubuntu-toolchain-r/test"
+
+    - os: linux
+      dist: bionic
+      compiler: gcc-UBSAN
+      env: UBSAN=1 TOOLSET=gcc COMPILER=g++-9 CXXSTD=03,11,14,17,2a UBSAN_OPTIONS=print_stacktrace=1 LINKFLAGS=-fuse-ld=gold
+      addons:
+        apt:
+          packages:
+            - g++-9
+          sources:
+            - sourceline: "ppa:ubuntu-toolchain-r/test"
+
+# clang, Linux
+    - os: linux
+      dist: trusty
+      compiler: clang-3.5
+      env: TOOLSET=clang COMPILER=clang++-3.5 CXXSTD=03,11
+      addons:
+        apt:
+          packages:
+            - clang-3.5
+            - libstdc++-4.9-dev
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: "deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-3.5 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: trusty
+      compiler: clang-3.6
+      env: TOOLSET=clang COMPILER=clang++-3.6 CXXSTD=03,11
+      addons:
+        apt:
+          packages:
+            - clang-3.6
+            - libstdc++-5-dev
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: "deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-3.6 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: trusty
+      compiler: clang-3.7
+      env: TOOLSET=clang COMPILER=clang++-3.7 CXXSTD=03,11
+      addons:
+        apt:
+          packages:
+            - clang-3.7
+            - libstdc++-5-dev
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: "deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-3.7 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: xenial
+      compiler: clang-3.8
+      env: TOOLSET=clang COMPILER=clang++-3.8 CXXSTD=03,11,14,1z
+      addons:
+        apt:
+          packages:
+            - clang-3.8
+            - libstdc++-6-dev
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-3.8 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: xenial
+      compiler: clang-3.9
+      env: TOOLSET=clang COMPILER=clang++-3.9 CXXSTD=03,11,14,1z
+      addons:
+        apt:
+          packages:
+            - clang-3.9
+            - libstdc++-6-dev
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-3.9 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: xenial
+      compiler: clang-4
+      env: TOOLSET=clang COMPILER=clang++-4.0 CXXSTD=03,11,14,1z
+      addons:
+        apt:
+          packages:
+            - clang-4.0
+            - libstdc++-6-dev
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-4.0 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: xenial
+      compiler: clang-5
+      env: TOOLSET=clang COMPILER=clang++-5.0 CXXSTD=03,11,14,1z
+      addons:
+        apt:
+          packages:
+            - clang-5.0
+            - libstdc++-7-dev
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-5.0 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: xenial
+      compiler: clang-6
+      env: TOOLSET=clang COMPILER=clang++-6.0 CXXSTD=03,11,14,17,2a
+      addons:
+        apt:
+          packages:
+            - clang-6.0
+            - libstdc++-8-dev
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-6.0 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: xenial
+      compiler: clang-7
+      env: TOOLSET=clang COMPILER=clang++-7 CXXSTD=03,11,14,17,2a
+      addons:
+        apt:
+          packages:
+            - clang-7
+            - libstdc++-8-dev
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-7 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: xenial
+      compiler: clang-8
+      env: TOOLSET=clang COMPILER=clang++-8 CXXSTD=03,11,14,17,2a
+      addons:
+        apt:
+          packages:
+            - clang-8
+            - libstdc++-8-dev
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-8 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: xenial
+      compiler: clang-9
+      env: TOOLSET=clang COMPILER=clang++-9 CXXSTD=03,11,14,17,2a
+      addons:
+        apt:
+          packages:
+            - clang-9
+            - libstdc++-9-dev
+          sources:
+            - sourceline: "ppa:ubuntu-toolchain-r/test"
+            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-9 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: xenial
+      compiler: clang-UBSAN
+      env: UBSAN=1 TOOLSET=clang COMPILER=clang++-9 CXXSTD=03,11,14,17,2a UBSAN_OPTIONS=print_stacktrace=1
+      addons:
+        apt:
+          packages:
+            - clang-9
+            - libstdc++-9-dev
+          sources:
+            - sourceline: "ppa:ubuntu-toolchain-r/test"
+            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-9 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: xenial
+      compiler: clang-libc++
+      env: TOOLSET=clang COMPILER=clang++-9 CXXSTD=03,11,14,17,2a CXXFLAGS="-stdlib=libc++" LINKFLAGS="-stdlib=libc++"
+      addons:
+        apt:
+          packages:
+            - clang-9
+            - libc++-9-dev
+            - libc++abi-9-dev
+          sources:
+            - sourceline: "ppa:ubuntu-toolchain-r/test"
+            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-9 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+    - os: linux
+      dist: xenial
+      compiler: clang-libc++-UBSAN
+      env: UBSAN=1 TOOLSET=clang COMPILER=clang++-9 CXXSTD=03,11,14,17,2a UBSAN_OPTIONS=print_stacktrace=1 CXXFLAGS="-stdlib=libc++" LINKFLAGS="-stdlib=libc++"
+      addons:
+        apt:
+          packages:
+            - clang-9
+            - libc++-9-dev
+            - libc++abi-9-dev
+          sources:
+            - sourceline: "ppa:ubuntu-toolchain-r/test"
+            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-9 main"
+              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
+
+# clang, OS X
+    - os: osx
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
+      osx_image: xcode9.4
 
     - os: osx
-      compiler: clang++
-      env: TOOLSET=clang CXXSTD=03,11,14,1z
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
+      osx_image: xcode10.3
+
+    - os: osx
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,17
+      osx_image: xcode11.2
 
 install:
   - GIT_FETCH_JOBS=8
@@ -85,8 +378,10 @@ install:
   - ./b2 headers
 
 script:
+  - |-
+    echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
   - BUILD_JOBS=`(nproc || sysctl -n hw.ncpu) 2> /dev/null`
-  - ./b2 -j $BUILD_JOBS libs/iterator/test toolset=$TOOLSET cxxstd=$CXXSTD
+  - ./b2 -j $BUILD_JOBS libs/iterator/test toolset=$TOOLSET cxxstd=$CXXSTD ${UBSAN:+cxxflags=-fsanitize=undefined cxxflags=-fno-sanitize-recover=undefined linkflags=-fsanitize=undefined define=UBSAN=1 debug-symbols=on visibility=global} ${CXXFLAGS:+cxxflags="$CXXFLAGS"} ${LINKFLAGS:+linkflags="$LINKFLAGS"}
 
 notifications:
   email:
diff --git a/appveyor.yml b/appveyor.yml
index 447a667..2249a0a 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,4 +1,5 @@
 # Copyright 2017 Edward Diener
+# Copyright 2019 Andrey Semashev
 # Distributed under the Boost Software License, Version 1.0.
 # (See accompanying file LICENSE_1_0.txt or copy at http://boost.org/LICENSE_1_0.txt)
 
@@ -14,13 +15,43 @@ branches:
 
 environment:
   matrix:
-    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
-      TOOLSET: msvc-9.0,msvc-10.0,msvc-11.0,msvc-12.0
-    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-      TOOLSET: msvc-14.0
-    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-      TOOLSET: msvc-14.1
+    - TOOLSET: msvc-9.0,msvc-10.0,msvc-11.0,msvc-12.0
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    - TOOLSET: msvc-14.0
+      ADDRMD: 32,64
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    - TOOLSET: msvc-14.1
       CXXSTD: 14,17
+      ADDRMD: 32,64
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+    - TOOLSET: msvc-14.2
+      ADDRMD: 32,64
+      CXXSTD: 14,17
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+    - TOOLSET: clang-win
+      ADDRMD: 32,64
+      CXXSTD: 14,17
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+    - TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+      ADDPATH: C:\cygwin\bin;
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    - TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+      ADDPATH: C:\cygwin64\bin;
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    - TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+      ADDPATH: C:\mingw\bin;
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    - TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+      ADDPATH: C:\mingw-w64\x86_64-6.3.0-posix-seh-rt_v5-rev1\mingw64\bin;
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    - TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+      ADDPATH: C:\mingw-w64\x86_64-7.3.0-posix-seh-rt_v5-rev0\mingw64\bin;
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
 
 install:
   - set GIT_FETCH_JOBS=8
@@ -43,5 +74,7 @@ install:
 build: off
 
 test_script:
+  - PATH=%ADDPATH%%PATH%
   - if not "%CXXSTD%" == "" set CXXSTD=cxxstd=%CXXSTD%
-  - b2 -j %NUMBER_OF_PROCESSORS% libs/iterator/test toolset=%TOOLSET% %CXXSTD%
+  - if not "%ADDRMD%" == "" set ADDRMD=address-model=%ADDRMD%
+  - b2 -j %NUMBER_OF_PROCESSORS% libs/iterator/test toolset=%TOOLSET% %CXXSTD% %ADDRMD%