Travis-CI: Also build and test with GCC 9.x

Author: ubruhin

.travis.yml

@@ -38,6 +38,14 @@ matrix:
           packages:
              - g++-8
       env: COMPILER=g++-8 CXXSTD=11
+    - compiler: gcc
+      addons:
+        apt:
+          sources:
+             - ubuntu-toolchain-r-test
+          packages:
+             - g++-9
+      env: COMPILER=g++-9 CXXSTD=11
     - compiler: gcc
       addons:
         apt:
@@ -168,6 +176,14 @@ matrix:
           packages:
              - g++-8
       env: COMPILER=g++-8 CXXSTD=14
+    - compiler: gcc
+      addons:
+        apt:
+          sources:
+             - ubuntu-toolchain-r-test
+          packages:
+             - g++-9
+      env: COMPILER=g++-9 CXXSTD=14
     - compiler: clang
       addons:
         apt:

README.md

@@ -100,6 +100,7 @@ Tested on:
   * clang 3.7
   * clang 3.6
   * clang 3.5
+  * g++ 9.1.0
   * g++ 8.0.1
   * g++ 7.3
   * g++ 6.4