Easy way find uninitialized member variables

Question

I am looking for an easy way to find uninitialized class member variables.

Finding them in either runtime or compile time is OK.

Currently

Answer 1

Beware! Compiler options proposed here are neither reliable, nor version-independent. Consider the simple example:

class A {
  int a;
public:
  void mA() {
    printf("haha");
    ++a;
    int g = 2/a;
    printf("%i\n",g);
  }
};

int main() {
  A a;
  a.mA();
}

Compiled with g++ -O3 -Weffc++ -Wuninitialized this thing reports uninitialized on gcc versions up to 4.6 inclusive, and passess happily on 4.7 and 4.8 (tested on MacPorts). Then, curiously, if we remove the printf("haha");, both 4.7 and 4.8 suddenly see uninitialized A::a. Clang is a little better, since it somehow assigns rubbish (instead of convenient 0) to uninitialized vars, so you see their disastrous effect easier/sooner.

I didn't have much luck in spotting the above uninitialized A::a with valgrind either; maybe the gentlement suggesting valgrind could provide appropriate options to spot this error.

Bottom line: great question, not much reliable solutions at the moment... (the way I see it).