[boost] Reporting accurate code coverage

General Code Coverage Tip (for everyone): Measure your coverage using branches, not lines. Branch coverage tells you how well error cases are tested and therefore a far better measure of quality than line-based. I have seen over 90% line coverage but the branch coverage is more like 60% to 70% on average over the boost CMT-managed repositories. Here's the shell script I use on travis to generate the data and feed it to codecov.io: https://github.com/jeking3/boost-ci/blob/master/ci/travis/codecov.sh The trick is to feed --rc lcov_branch_coverage=1 to the correct commands to generate and preserve the branch information. Thanks, - Jim