extern "C"
/// This macro doesn't panic. Instead it tries to call a non-existing function. If the compiler can
/// prove it can't be called and optimizes it away, the code will compile just fine. Otherwise you get
/// a linking error.
///
/// This should be used only in cases you are absolutely sure are OK and optimizable by compiler.
/// This macro is active only with `panic` feature turned on and it will really panic, instead of
/// causing a linking error. The purpose is to make development easier. (E.g. in debug mode.)