Question

My code is below. However before main() is run something simple such as a static std::string globalvar; will call new. Before MyPool mypool is initialized.

MyPool mypool;
void* operator new(size_t s) { return mypool.donew(s); }

Is there anyway I can force mypool to be initialized first? I have no idea how overloading new is suppose to work if there is no way to initialize its values so I am sure there is a solution to this.

I am using both visual studios 2010 and gcc (cross platform)

Answer 1

Make mypool a static variable of your operator new function:

void* operator new(size_t s) {
   static MyPool mypool;
   return mypool.donew(s);
}

It will be initialized upon first call of the function (i.e. the operator new).

EDIT: As the commenters pointed out, declaring the variable as static in the operator new functions limits its scope and makes it inaccessible in the operator delete. To fix that, you should make an accessor function for your pool object:

MyPool& GetMyPool() {
  static MyPool mypool;
  return mypool;
}

and invoke it in both operator new and operator delete:

void* operator new(size_t s) {
    return GetMyPool().donew(s);
}
// similarly for delete

As before, declaring it as static local variable guarantees initialization upon first invocation of GetMyPool function. Additionally, it will be the same pool object in both operators which likely what you want.