Re: POD initialization

From:

pallav <pallavgupta@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Wed, 20 Jun 2007 01:06:39 -0000

Message-ID:

<1182301599.669546.218470@p77g2000hsh.googlegroups.com>

On Jun 19, 8:26 pm, "Victor Bazarov" <v.Abaza...@comAcast.net> wrote:

The struct above is not a POD-struct. It contains a 'vector',
which is non-POD. When an object of this struct is default-
initialised, each member is default-initialised. For the 'pins'
vector it means to default-initialise (invoke the constructor),
for built-ins it means to NOT initialise.

If you look at 'dc->wltable' _right_here_, what would it be?
I would say that both 'slope' and 'npinset' would have garbage.

Yes I see it now. Since it is allocating from the heap it is not
initialized and hence contains garbage.

dc->wltable.slope = DELAY_VALUE_NOT_GIVEN;
dc->pipomodel = PinDelayPtr(new
PinDelay(*unspecifiedPipoDelayModel));
}

Since the struct contain POD (plain old data), I would think they
should be initialized to 0.

No.

It's not supposed to. Add a constructor to your 'DelayCircuitImpl'
_and_ to 'DelayWireLoadTable'.

Right I understand now.

How about this:
------------------------------
#include <vector>
struct A {
    int a;
    std::vector<int> vi;

};

#include <iostream>
struct B {
    A *pa;
    B() : pa(new A()) {
        std::cout << pa->a << ' ' << pa->vi.size() << std::endl;
    }

};

int main() {
    B b;}

-----------------------------
It should print something non-zero and then 0.

Yes, it does.

Many thanks for the time/help everybody.