language: cpp
compiler:
  - clang
  - gcc
script: ./scripts/run-tests.sh

language: cpp
matrix:
  include:
    - os: linux
      addons:
        apt:
          sources:
            - ubuntu-toolchain-r-test
          packages:
            - g++-4.9
      env:
        - MATRIX_EVAL="CC=gcc-4.9 && CXX=g++-4.9"
    - os: linux
      addons:
        apt:
          sources:
            - ubuntu-toolchain-r-test
          packages:
            - g++-5
      env:
        - MATRIX_EVAL="CC=gcc-5 && CXX=g++-5"
    - os: linux
      addons:
        apt:
          sources:
            - ubuntu-toolchain-r-test
          packages:
            - g++-6
      env:
        - MATRIX_EVAL="CC=gcc-6 && CXX=g++-6"
    - os: linux
      addons:
        apt:
          sources:
            - ubuntu-toolchain-r-test
          packages:
            - g++-7
      env:
        - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"
    - os: linux
      env:
        - MATRIX_EVAL="CC=clang && CXX=clang++"
before_install:
  - eval "${MATRIX_EVAL}"
script:
  - ./scripts/run-tests.sh

Test against more modern versions of GCC
Test against more modern versions of GCC

Modify Travis CI configuration so that it tests against more modern
versions of GCC, as the one used by default is lacking of C++11 support.
