Question

If I code this

std::map<int, char> example = {
                                (1, 'a'),
                                (2, 'b'),
                                (3, 'c') 
                              };

then g++ says to me

deducing from brace-enclosed initializer list requires #include <initializer_list>
in C++98 ‘example’ must be initialized by constructor, not by ‘{...}’   

and that annoys me slightly because the constructor is run-time and can, theoretically fail.

Sure, if it does, it will fail quickly and ought to do so consistently, so that I ought to quickly locate & correct the problem.

But, still, I am curious – is there anyway to initialize map, vector, etc, at compile time?

---

Edit: I should have said that I am developing for embedded systems. Not all processors will have a C++0x compiler. The most popular probably will, but I don’t want to encounter a gotcha & have to maintain 2 versions of the code.

As to Boost, I am undecided. They are wishy-washy on the use of their Finite State Machine classes in embedded systems, so that is actually what I am coding here, Event/State/Fsm classes.

Sigh, I guess I’d better just play it safe, but I hope that this discussion has been helpful for others.

Answer 1

Not in C++98. C++11 supports this, so if you enable C++11 flags and include what g++ suggests, you can.

Edit: from gcc 5 C++11 is on by default