This is what is called API and ABI stability. Most well-known C and C++ libraries have been API and ABI stable for years.
In practice, this hasn't been a problem for my C++ projects for years, except on OS X where there have been too many changes in a couple of years (gcc -> gcc-llvm -> clang, libstdc++ -> libc++).
In practice, this hasn't been a problem for my C++ projects for years, except on OS X where there have been too many changes in a couple of years (gcc -> gcc-llvm -> clang, libstdc++ -> libc++).