initialization list question, with emphasis on std vector

Question

newbie here, in order to help sort out problems in my C++ project, I am compiling with the -Weffc++ option in g++.

It's giving me hundreds of warnings about "warning ... should be initialized in the member initialization list"

Is this really necessary seeing as it will a) take a bit of time to write them all in, and b) make make things messier when I was happy initialising variables when they are need only.

But more specifically, how do I initialise a std::vector?

Is this the way, ie just putting a 0 in brackets? My header:

class Blade;
class Postpro {
   public:
     Postpro(string fName) : theFileName(fName),
                             blade(NULL),
                             sizes(10),
                             t(std::vector<double>(0){};
     ~Postpro(){};
     void test();

   private:
     string theFileName;
     Blade* blade;
     int sizes;
     std::vector<double> t;
}

And then in the cpp I just resize the vector if I want to use it?

void Postpro::test() {
    blade = new Blade;
    t.resize(37);
}

Thanks

Answer 1

It does not take that much time to type, because you have typed too much:

Instead of

t(std::vector<double>(0))

you could write

t(0)

which should be the same as

t()

---

The warning might be a bit too pedantic. Classes with a default constructor will be automatically initialized anyway. A warning flag to alert you only of uninitialized POD members would seem more valuable (otherwise you get too much noise).

May-be the use is that it shows the reader that you indeed meant to use the default constructor to initialize that member.