The latter does not require any name mangling. Any function that is called, was first created by the programmer. You might not like it, but it certainly fits an

The latter does not require any name mangling. Any function that is called, was first created by the programmer. You might not like it, but it certainly fits any C code that wants to interface with other languages. Furthermore, I could only find this feature in the clang-compiler and references to it outside of the online-docs in gcc.