Proper way to set compiler and language standard in CMake

[ben.boeckel (Ben Boeckel (Kitware))]

@adaldev

the best way is so to delete the build tree before calling cmake again with a -DCMAKE_CXX_COMPILER=… for instance?

I would make a build tree per compiler instead of starting from scratch each time.

@adaldev

But I had also surprises with target_compile_feature and gcc 5.5 (sorry I can’t upload an example) as the requested language level was not set. When should I use target_compile_feature (with respect to project, add_library/add_executable?)

add_library(mytarget) # or add_executable()
target_compile_features(mytarget PRIVATE cxx_std_14) # or PUBLIC if you use C++14 in headers.

@adaldev

I must support xenial versions as my users may not be able to upgrade their applications.

CMake’s downloads do not require special permissions to install; one extracts the tarball and uses it in-place.