C != C++. Really wish people would stop lumping them together. Compilers support both, but many compilers also support D, Obj-C, Obj-C++, assembly, etc.
This article focuses almost entirely on C++, but the title would have you think otherwise.
Hi, I don't agree to the end as most of the options are equally applicable to C language except libcxx and others. ThinLTO, inline threshold -- they also can be turned on for C compilation units