[iwanders]

This implements the proposed workaround to get the target fetaures to work on CMake versions before 3.8. I've confirmed this works on CMake 3.5.1, which is shipped with Ubuntu 16.04.

This relates to the discussion in #1428. And replaces pending PR #1440.

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• Changes are described in the pull request, or an existing issue is referenced.
• The test suite compiles and runs without error.
• Code coverage is 100%. Test cases can be added by editing the test suite.
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Please don't

• The C++11 support varies between different compilers and versions. Please note the list of supported compilers. Some compilers like GCC 4.7 (and earlier), Clang 3.3 (and earlier), or Microsoft Visual Studio 13.0 and earlier are known not to work due to missing or incomplete C++11 support. Please refrain from proposing changes that work around these compiler's limitations with #ifdefs or other means.
• Specifically, I am aware of compilation problems with Microsoft Visual Studio (there even is an issue label for these kind of bugs). I understand that even in 2016, complete C++11 support isn't there yet. But please also understand that I do not want to drop features or uglify the code just to make Microsoft's sub-standard compiler happy. The past has shown that there are ways to express the functionality such that the code compiles with the most recent MSVC - unfortunately, this is not the main objective of the project.
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[iwanders]

Had to update the PR, I didn't modify the benchmark CMakeLists. The workaround didn't work because there's some weird stuff going on in the benchmark/thirdparty folder. The main CmakeLists there requires cmake version 2.8.12, yet the cmake at the source files uses the FILTER directive on a list, which was only added in CMake 3.6.3. I chose to revert the benchmark folder to require CMake 3.8 again.

[coveralls]

Coverage remained the same at 100.0% when pulling 4fd9b52 on iwanders:support-cmake-older-than-3-8-with-if into dffae10 on nlohmann:develop.

[iwanders]

Reopened as per discussion on #1440

[iwanders]

@nlohmann , friendly ping, this one is good for merge. @pboettch has approved this after our discussoin on #1440, that PR can be closed when this goes in.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[iwanders]

This should not be marked stale imo, we've had discussion on @1440 about this PR and decided that this is the best way of solving the problem. @pboettch has approved this a month ago. @nlohmann , if you have comments / concerns I'd be happy to address them, otherwise this can go in.

[nlohmann]

Sorry, but I am quite busy right now, so I did not find the time to check at this repo lately :-/

[iwanders]

Ok, I understand, we've prevented the issue from getting closed which is good enough for today 👍

[nlohmann]

Looks good to me.

[nlohmann]

Thanks a lot!!!