fix compilation in Kinetic

[facontidavide]

No description provided.

[svwilliams]

There is a build server running that tests Xenial/Kinetic builds, but I believe that build server has a set of default compile flags that get added. So these errors slipped through the cracks. So thanks for this PR.

I am going to attempt to fix this the "correct" way by specifying the needed target_compile_features(). If I can work it out, I'll post a link to an alternate PR for you to try in a day or two. And if I can't, I'll get this merged.

[efernandez]

This looks more like it's trying to disable gnu extensions, which it's something I encountered trying to use Ceres 2.0, although I'm not using it at the moment: https://cmake.org/cmake/help/v3.15/variable/CMAKE_CXX_STANDARD.html, https://cmake.org/cmake/help/v3.15/prop_tgt/CXX_STANDARD.html#prop_tgt:CXX_STANDARD, https://cmake.org/cmake/help/v3.15/prop_tgt/CXX_EXTENSIONS.html#prop_tgt:CXX_EXTENSIONS

If that's the intention, we should do set(CMAKE_CXX_EXTENSIONS OFF), as it's already done in fuse_constraints and fuse_core.

👍 for using target_compile_features. IIRC only newer versions of CMake propagate this stuff properly though. FYI I'm using version 3.5.1 in my system. I wonder which version are you guys using.

[svwilliams]

@facontidavide Can I get some more details about the compilation issue you are experiencing?

I created a virtual machine running Ubuntu 16.04 + ROS Kinetic, made a workspace containing the fuse packages and tf2_2d, and installed all dependencies using rosdep. Everything compiled without error, and all of the unit tests passed.

I want to make sure I can reproduce the issue, so that I know any compilation changes I make will fix it.

@efernandez target_compile_features was introduced in Cmake 3.1. Ubuntu 16.04's default version of CMake is 3.5.1. I feel safe increasing the required cmake version to 3.1.

[facontidavide]

For some reason it was complaining about variadic lambdas. But this happened only on one of my two laptops, so it might be hard to reproduce

[svwilliams]

My attempt at using target_compile_features() was not particularly successful. I am reverting to the suggestion here to set CMAKE_CXX_STANDARD instead. I have a test branch, if you have time to give it a try. It starts with your PR and cleans up some additional compile flags. If that works for you, I'll add my changes to this PR and get it merged in.