.travis.yml

matrix:
  include:
    # works on Precise and Trusty
    - os: linux
      addons:
        apt:
          sources:
            - ubuntu-toolchain-r-test
          packages:
            - g++-4.9
      env:
         - MATRIX_EVAL="CC=gcc-4.9 && CXX=g++-4.9"

    # works on Precise and Trusty
    - os: linux
      addons:
        apt:
          sources:
            - ubuntu-toolchain-r-test
          packages:
            - g++-5
      env:
         - MATRIX_EVAL="CC=gcc-5 && CXX=g++-5"

    # works on Precise and Trusty
    - os: linux
      addons:
        apt:
          sources:
            - ubuntu-toolchain-r-test
          packages:
            - g++-6
      env:
        - MATRIX_EVAL="CC=gcc-6 && CXX=g++-6"

    # works on Precise and Trusty
    - os: linux
      addons:
        apt:
          sources:
            - ubuntu-toolchain-r-test
          packages:
            - g++-7
      env:
        - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"

    - os: osx
      osx_image: xcode8
      env:
        - MATRIX_EVAL="CC=gcc-4.9 && CXX=g++-4.9"

    - os: osx
      osx_image: xcode8
      env:
        - MATRIX_EVAL="brew install gcc5 && CC=gcc-5 && CXX=g++-5"

    - os: osx
      osx_image: xcode8
      env:
        - MATRIX_EVAL="brew install gcc6 && CC=gcc-6 && CXX=g++-6"

    - os: osx
      osx_image: xcode8
      env:
        - MATRIX_EVAL="brew install gcc && CC=gcc-7 && CXX=g++-7"

    # works on Precise and Trusty
    - os: linux
      addons:
        apt:
          sources:
            - ubuntu-toolchain-r-test
            - llvm-toolchain-precise-3.6
          packages:
            - clang-3.6
      env:
        - MATRIX_EVAL="CC=clang-3.6 && CXX=clang++-3.6"

    # works on Precise and Trusty
    - os: linux
      addons:
        apt:
          sources:
            - ubuntu-toolchain-r-test
            - llvm-toolchain-precise-3.7
          packages:
            - clang-3.7
      env:
        - MATRIX_EVAL="CC=clang-3.7 && CXX=clang++-3.7"

    # works on Precise and Trusty
    - os: linux
      addons:
        apt:
          sources:
            - ubuntu-toolchain-r-test
            - llvm-toolchain-precise-3.8
          packages:
            - clang-3.8
      env:
        - MATRIX_EVAL="CC=clang-3.8 && CXX=clang++-3.8"

    # works on Trusty
    - os: linux
      addons:
        apt:
          sources:
            - llvm-toolchain-trusty-3.9
          packages:
            - clang-3.9
      env:
        - MATRIX_EVAL="CC=clang-3.9 && CXX=clang++-3.9"

    # works on Trusty
    - os: linux
      addons:
        apt:
          sources:
            - llvm-toolchain-trusty-4.0
          packages:
            - clang-4.0
      env:
        - MATRIX_EVAL="CC=clang-4.0 && CXX=clang++-4.0"

    # works on Trusty
    - os: linux
      addons:
        apt:
          sources:
            - llvm-toolchain-trusty-5.0
          packages:
            - clang-5.0
      env:
        - MATRIX_EVAL="CC=clang-5.0 && CXX=clang++-5.0"

    - os: osx
      osx_image: xcode10.1

    - os: osx
      osx_image: xcode9.4

before_install:
    - eval "${MATRIX_EVAL}"