Re: Initializing: class within structure

From:

Richard Herring <junk@[127.0.0.1]>

Newsgroups:

comp.lang.c++

Date:

Tue, 11 Jul 2006 15:52:00 +0100

Message-ID:

<f$pZoDuQs7sEFw7t@baesystems.com>

In message <1152627913.652846.13320@35g2000cwc.googlegroups.com>, ScottM
<scott@mayo.name> writes

I expect this has been covered somewhere, but I can't find it. Given:

class A { public:
A() {...does stuff...}
};

struct S {
A a;
};

If I create an instance of S, is A's initializer guaranteed to run? Put
differently, is the compiler committed to search down through many
levels to find things with constructors? (I know it will, of course, if
S is a class.)

Yes.

I've run across verbiage that claims that struct is the same as class
with an initial public: specification,

And default public inheritance.

but I thought I recalled that
structs and classes differed more than that.

You're possibly thinking of another, slightly related, language with C
in its name.

If they don't, if the
intent is to write a POD with public data, just a few simple
constructors

If it has constructors it isn't a POD!

and no use of virtual, does it simply make more sense to
use struct, to make that intention clearer?

Yes. It's a common convention in some circles -- but if you're going to
use it consistently as a documentation tool you need to spell out
exactly what your chosen rules will be.

--
Richard Herring