C++ compile-time constant detection

Question

There\'re cases when a library source is available, and it has to support variable parameters in general, but in practice these parameters are commonly constants.

Th

Answer 1

If you're working with GCC, use __builtin_constant_p to tell you whether something is a compile time constant. The documentation includes examples like

static const int table[] = {
  __builtin_constant_p (EXPRESSION) ? (EXPRESSION) : -1,
  /* ... */
};