Can C++ compilers optimize “if” statements inside “for” loops?

Question

Consider an example like this:

if (flag)
  for (condition)
    do_something();
else
  for (condition)
    do_something_else();

If fla

Answer 1

As many have said: it depends.

If you want to be sure, you should try to force a compile-time decision. Templates often come in handy for this:

for (condition)
  do_it();