Uses of C comma operator [duplicate]

Answer 1

I often use it to run a static initializer function in some cpp files, to avoid lazy initalization problems with classic singletons:

void* s_static_pointer = 0;

void init() {
    configureLib(); 
    s_static_pointer = calculateFancyStuff(x,y,z);
    regptr(s_static_pointer);
}

bool s_init = init(), true; // just run init() before anything else

Foo::Foo() {
  s_static_pointer->doStuff(); // works properly
}