For certain task, I didn't manage to get away without macro. Now I'd like to add at least some protection from misuse.
I'd like to static_assert that MYMACRO() is used
- in a subclass of Base class,...
- ...namely, in
run()method
A naive approach fails:
static_assert(std::is_base_of<Base, typeid(*this)>::value, "Use MYMACRO() only in subclass of Base.");// =============// SubOne would work, but not typeid(*this)//static_assert(__func__ == "run", "Use MYMACRO() only in run() method.");// ========// not a constexpr?//To reproduce:
#ifndef __GNUG__#error "Needs GCC C++"#endif#define MYMACRO() \{\ do { \ /*> > > want static_assert'ions here < < <*/\ /*here comes stuff I coudn't put into an [inline] function,*/ \ /*because it contains GCC Labels-as-Values and */ \ /*conditional return;*/ \ } while(false);\}class Base {public: virtual int run() = 0;};class SubOne : Base {public: int run() override { // ... MYMACRO(); // ... };};class SubTwo : Base {public: int run() override { // ... MYMACRO(); // ... };};int main(void) { SubOne sub1; SubTwo sub2; //a little embedded app while (true) { sub1.run(); sub2.run(); }}Anticipating possible questions:
What is it for? - http://dunkels.com/adam/dunkels06protothreads.pdf
Labels as values: - https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
Why not "proper"RTOS with context switching? - I expect the above solution to simplify unit testing under native architecture, side-stepping the need for native (POSIX) port or QEMU/renode or target board. (Not for all, but for many tests)
