Require C++11 and CMake 3.10

[akohlmey]

Summary

This adds tests and documents the new requirements for C++ compiler and CMake.

Related Issues

Closes #1659
Closes #1729

Author(s)

Axel Kohlmeyer (Temple U)

Licensing

By submitting this pull request, I agree, that my contribution will be included in LAMMPS and redistributed under either the GNU General Public License version 2 (GPL v2) or the GNU Lesser General Public License version 2.1 (LGPL v2.1).

Backward Compatibility

This deliberately breaks compatibility with old compilers and CMake versions

Post Submission Checklist

• The feature or features in this pull request is complete
• Licensing information is complete
• Corresponding author information is complete
• The source code follows the LAMMPS formatting guidelines
• Suitable new documentation files and/or updates to the existing docs are included
• The added/updated documentation is integrated and tested with the documentation build system
• The feature has been verified to work with the conventional build system
• The feature has been verified to work with the CMake based build system

[junghans]

With cmake-3.10 we can also get rid of LAMMPS_LINK_LIBS and LMP_SOURCES as one can simply create the library/executable target at the beginning of the CMake file with e.g. add_excutable(lmp) (no source files) and then add source files with target_sources(lmp foo.cpp), similar for linking with target_link_libraries(lmp foo::foo).

[akohlmey]

With cmake-3.10 we can also get rid of LAMMPS_LINK_LIBS and LMP_SOURCES as one can simply create the library/executable target at the beginning of the CMake file with e.g. add_excutable(lmp) (no source files) and then add source files with target_sources(lmp foo.cpp), similar for linking with target_link_libraries(lmp foo::foo).

Feel free to submit a pull request with those changes. Either to this branch or to master.

[junghans]

Modules/Testing.cmake makes use of a cmake-3.11 feature, so we might want make that the minimum.

[akohlmey]

Modules/Testing.cmake makes use of a cmake-3.11 feature, so we might want make that the minimum.

No. #1723 has the reasoning why 3.10 was chosen. lammps-testing is still an ad hoc package and not something that we should encourage non-expert users to use. I think including it in the CMake configuration at this stage is not a good idea.