Travis: add gcc-9, clang-7,8,9, upgrade to xenial

Author: ryanhaining

.travis.yml

@@ -1,5 +1,5 @@
 language: cpp
-dist: trusty
+dist: xenial
 sudo: require
 
 matrix:
@@ -10,14 +10,15 @@ matrix:
         apt:
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-5.0
+            - llvm-toolchain-xenial
           packages:
             - clang-5.0
             - clang++-5.0
             - valgrind
             - gcc-8-base
             - libc6
             - libgcc1
+            - scons
       env:
         - COMPILER=clang++-5.0
         - USE_LIBCXX=1
@@ -27,17 +28,75 @@ matrix:
         apt:
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-6.0
+            - llvm-toolchain-xenial
           packages:
             - clang-6.0
             - clang++-6.0
             - valgrind
             - gcc-8-base
             - libc6
             - libgcc1
+            - scons
       env:
         - COMPILER=clang++-6.0
         - USE_LIBCXX=1
+    - os: linux
+      compiler: clang
+      addons:
+        apt:
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-xenial-7
+          packages:
+            - clang-7
+            - clang++-7
+            - valgrind
+            - gcc-8-base
+            - libc6
+            - libgcc1
+            - scons
+      env:
+        - COMPILER=clang++-7
+        - USE_LIBCXX=1
+    - os: linux
+      compiler: clang
+      addons:
+        apt:
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-xenial-8
+          packages:
+            - clang-8
+            - clang++-8
+            - valgrind
+            - gcc-8-base
+            - libc6
+            - libgcc1
+            - scons
+      env:
+        - COMPILER=clang++-8
+        - USE_LIBCXX=1
+    - os: linux
+      compiler: clang
+      addons:
+        apt:
+          sources:
+            - ubuntu-toolchain-r-test
+              # travis complains about an unlisted source here if I do it with a plain
+              # llvm-toolchain-xenial-9
+            - sourceline: 'deb https://apt.llvm.org/xenial/ llvm-toolchain-xenial-9 main'
+              key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'
+          packages:
+            - clang-9
+            - clang++-9
+            - valgrind
+            - gcc-8-base
+            - libc6
+            - libgcc1
+            - scons
+      env:
+        - COMPILER=clang++-9
+        - USE_LIBCXX=1
     - os: linux
       addons:
         apt:
@@ -46,6 +105,7 @@ matrix:
           packages:
             - g++-7
             - valgrind
+            - scons
       env:
         - COMPILER=g++-7
     - os: linux
@@ -56,8 +116,20 @@ matrix:
           packages:
             - g++-8
             - valgrind
+            - scons
       env:
         - COMPILER=g++-8
+    - os: linux
+      addons:
+        apt:
+          sources:
+            - ubuntu-toolchain-r-test
+          packages:
+            - g++-9
+            - valgrind
+            - scons
+      env:
+        - COMPILER=g++-9
 
 script:
   - ${COMPILER} --version

README.md

@@ -13,7 +13,7 @@ Follow [@cppitertools](https://twitter.com/cppitertools) for updates.
 #### Build and Test Status
 Status | Compilers
 ---- | ----
-[![Travis Build Status](https://travis-ci.com/ryanhaining/cppitertools.svg?branch=master)](https://travis-ci.com/ryanhaining/cppitertools) | gcc-7  gcc-8 clang-5.0 clang-6.0
+[![Travis Build Status](https://travis-ci.com/ryanhaining/cppitertools.svg?branch=master)](https://travis-ci.com/ryanhaining/cppitertools) | gcc-7 gcc-8 gcc-9 clang-5.0 clang-6.0 clang-7 clang-8 clang-9
 [![Appveyor Build Status](https://ci.appveyor.com/api/projects/status/github/ryanhaining/cppitertools?svg=true)](https://ci.appveyor.com/project/ryanhaining/cppitertools) | MSVC 2017 MSVC 2019
 
 #### Table of Contents