+ addons:
+ apt:
+ packages: ['gcc-6', 'g++-6']
+ sources: &sources
+ - ubuntu-toolchain-r-test
+
+ - env: PLATFORM=Unix COMPILER=gcc-7
+ compiler: gcc
+ os: linux
+ addons:
+ apt:
+ packages: ['gcc-7', 'g++-7']
+ sources: &sources
+ - ubuntu-toolchain-r-test
+
+ - env: PLATFORM=Unix COMPILER=clang-3.6